orthodontics for its patients, by dr claude mauclaire

ORTHODONTICS FOR ITS PATIENTS

By Dr. Claude MAUCLAIRE, Orthodontist

14, rue Ravelin 10000 Troyes

FRANCE [email protected]

March 2010

mailto:[email protected]

Orthodontics for its patients

© Dr.Claude Mauclaire 2010. All rights reserved 2

Table of Contents

CHAPTER I: INTRODUCTION ............................................................................................................ 5

Good Dental Health = Well Placed Teeth ................................................................................... 5

The Position of the Teeth is the Result of the Overall Way the Mouth Functions ...................... 5

Simple Principles of Hygiene to Keep Teeth Healthy................................................................. 6

Eating Well Means Good Health ................................................................................................. 6

Establishing a Good, Balanced Diet ............................................................................................ 7

Giving Up Dietary Excess ........................................................................................................... 7

Well Placed Teeth Throughout Life ............................................................................................ 8

BASIC PRINCIPLES .............................................................................................................................. 8

- A: Malformed Dentition is Not a Fatality ............................................................................... 8

- B: The Origin of Problems is Essentially Functional.............................................................. 8

- C: The Various Functions of the Mouth ................................................................................. 9

Chewing and Swallowing Food ...................................................................................... 9

Swallowing Saliva ........................................................................................................... 9

Speech ............................................................................................................................. 9

Breathing ....................................................................................................................... 10

Facial Expression .......................................................................................................... 10

- D: The Importance of Swallowing ........................................................................................ 10

Suction Swallowing in Babies and Toothless Elderly People ....................................... 11

Mature Swallowing in the Older Individual .................................................................. 11

The Importance of Mature Swallowing for the Teeth ................................................... 12

- E: The Flesh Sculpts the Bone and Positions the Teeth ........................................................ 12

- F: The Key Role of the Tongue in the Way the Mouth Functions ........................................ 13

The "Orchestra Conductor" of the Mouth ..................................................................... 13

Its Role in Articulating Words ...................................................................................... 14

Its Role in Swallowing .................................................................................................. 14

Its Role in Breathing...................................................................................................... 14

- G: Voluntary and Unconscious Movements ......................................................................... 15

- H: An Attractive Profile: the Decisive Role of the Lower Incisors ...................................... 16



CHAPTER II: PROGNATHISM .......................................................................................................... 18

- A: Prognathism, Alveolar Protrusion and Retrusion ............................................................ 18

Of the Upper Jaw or "Horse Teeth" .............................................................................. 18

Of the Lower Jaw or "Protruding Chin" ........................................................................ 22

- B: Labioversion without Prognathism .................................................................................. 25

Only in the Lower Jaw (Labioversion of the Mandibular Incisors) .............................. 25

Only in the Upper Jaw (Labioversion of the Maxillary Incisors).................................. 26

In Both Jaws at Once (Double Protrusion of the Incisors) ............................................ 26

CHAPTER III: WIDTH DEFORMITIES ............................................................................................. 29

- A: Upper Molars Wider Apart Than Lower Molars (Maxillary Expansion) ........................ 29

- B: Upper Molars Not as Wide Apart as Lower Molars (Maxillary Contraction) ................. 30

CHAPTER IV: VERTICAL DEFORMATION OF THE FACE .......................................................... 33

- A: Long Face (Vertical Growth) ........................................................................................... 33

- B: Square Face (Horizontal Growth) .................................................................................... 35

CHAPTER V: GENETIC ABNORMALITIES .................................................................................... 37

- A: Agenesis ........................................................................................................................... 37

- B: Supernumerary Teeth and Odontomas ............................................................................. 38

- C: Microdontia ...................................................................................................................... 38

- D: Crowding.......................................................................................................................... 38

- E: Impacted Teeth and Wisdom Teeth .................................................................................. 40

Impaction of the Upper Canines .................................................................................... 40

Wisdom Teeth ............................................................................................................... 42

- F: Cleft Lips .......................................................................................................................... 42

CHAPTER VI: FUNCTIONAL DEFORMITIES ................................................................................ 44

- A: Retained and Ankylosed Teeth ........................................................................................ 44

- B: Open Bite ......................................................................................................................... 45

The Three Main Types of Open Bite ............................................................................. 45

- 1: Unilateral Open Bite.............................................................................................. 45

- 2: Bilateral Open Bite ................................................................................................ 46

- 3: Total Open Bite ..................................................................................................... 47

Consequences of Open Bites ......................................................................................... 48

- 1: Jaw Joint Dysfunction ........................................................................................... 50

- 2: Tooth Grinding or Bruxism ................................................................................... 50

- C: Supraocclusion ................................................................................................................. 52

- D: Diastema or a Gap Between the Teeth ............................................................................. 55

- E: Neuralgia or Toothache .................................................................................................... 56

- F: Receding Gums or Periodontal Disease ........................................................................... 56

CHAPTER VII: CURING BY FUNCTIONAL RETRAINING .......................................................... 59



- A: Restoring Correct Function .............................................................................................. 59

Establishing Mature Swallowing ................................................................................... 60

Restoring Correct Articulation of Sounds ..................................................................... 61

Exercises ........................................................................................................................ 61

Establishing Correct Chewing ....................................................................................... 62

- B: Gaining a Beautiful Smile ................................................................................................ 64

By Correct Positioning of the Teeth on the Bone .......................................................... 64

By Correct Intercuspation and Good Alignment of the Teeth ...................................... 64

- C: Stabilizing the Results ................................................................................................... 65

Through Appropriate Exercises ..................................................................................... 65

By Fitting a Tooth Positioner ........................................................................................ 66

- D: The Use of Corrective Appliances ................................................................................... 67

The Activator ................................................................................................................. 67

The Crib ......................................................................................................................... 69

The Quad Helix ............................................................................................................. 70

The Delaire Mask .......................................................................................................... 71

CONCLUSION ..................................................................................................................................... 73

Theory Proven by the Results ................................................................................................... 73

The Case of Caroline O. ............................................................................................................ 73

In Support of Functional Retraining Orthodontics .................................................................... 76

SHORT GLOSSARY ............................................................................................................................ 78

INDEX

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CHAPTER I: INTRODUCTION

Good Dental Health = Well Placed Teeth

Having well placed teeth is not just a matter of aesthetics. Above all it guarantees that your dentition is strong and, consequently, healthy. Orthodontics, which literally means "the science of straight teeth,” is not satisfied with simply establishing an attractive smile but takes effective action in cases where there are oral and dental health problems.

During my many years' experience as an orthodontist I have become convinced that good dental health depends on certain basic principles that can be explained to anyone, and this is what I propose to do in this book.

The idea of writing this book came to me recently while I was reading an archeological report on examination of the skulls of our early ancestors. This report was considering some 600 prehistoric skulls exhumed from a necropolis in the southwest of France. In the skulls where the jaws were correctly aligned with the teeth in their right positions (they "interacted correctly"), the teeth were healthy: there were no caries or loose or missing teeth. In contrast, the jaws that were misshapen in any way had lost all their teeth.

What conclusion should we draw from that? Quite simply, that there is an undeniable relationship between the health of our teeth and how they are placed in the bone. What was true for our ancestors is also true for us.

The Position of the Teeth is the Result of the Overall Way the Mouth Functions

Marie Hélène G.

Olivier G.



We still need to understand what is meant by the teeth being in their correct position, and what the causes are, particularly of their not being so.

Is it Nature that places our teeth in a good or bad position right from birth? Many people believe this to be the case, but they are wrong since congenital abnormalities (abnormalities present from the time of birth) are not the most frequent cause of correct or incorrect positioning. Might it not instead be the individual himself who, day after day, shapes his own dentition, so that his teeth become well or badly placed in their bony support?

This is where we touch on the root of the problem of which most of us are unaware. My clinical experience has awakened me to the irrefutable fact that, apart from in rare cases, the positioning of the teeth is not innate and certainly not permanent, but results from the overall way the oral cavity functions.

Even if we must all make do with what Nature gives us at birth, we shape our own dentition. We need to be aware that the mouth is not a rigid system: the organs forming it have a certain plasticity or are even malleable—including the bony parts. We will see later what is meant by this.

The function or role of each part of the mouth—the tongue, lips, cheeks, jaws, teeth—helps shape the oral cavity as a whole. All the parts work together and should therefore be considered as a unified entity and not, as many believe, as separate items. The relationships between the parts of the mouth determine whether the teeth are well or badly positioned and consequently whether oral health is good or not.

Teeth with caries, receding gums, teeth poorly fixed in their bony base or not fitting together well (known as poor "intercuspation"), or even abnormal differences in level between the teeth which create open bite (i.e., space between the upper and lower teeth, which cannot therefore intercuspate), must not be treated as isolated problems. The functional defects of the other parts of the mouth which are the source of the problem must be examined and corrected.

The orthodontist will therefore seek to reestablish good overall function for all the elements of the mouth, in order to correct abnormal positioning and thus any health problems that may have developed as a consequence.

Simple Principles of Hygiene to Keep Teeth Healthy

After several decades of practice, I have gradually compiled a number of simple principles which, once understood and applied, make it possible to maintain healthy dentition throughout life. It is the simplicity of these principles and their empirical validation (which I will illustrate with dramatic examples) that made me decide to write this book for parents, particularly those whose children are going through the prime period of dental development. Good dentition can be achieved by following a few pieces of advice which can be perfectly understood by anyone.

Eating Well Means Good Health

The principles of dental hygiene that have come to the fore are based above all on the patient’s ordinary, everyday behavior. We need to analyze the way we usually do certain things, remembering that while our habits may be "second nature,” they are often bad and have been inflicted on us more by society than by Nature, particularly where eating is concerned.

The interests of the food industry are not necessarily compatible with good dental hygiene, nor with the interests of the human body as a whole, which must be constantly fed for it to develop, survive and defend itself against the bacterial and viral attacks that constantly assail it.

It is not fate that causes a large number of minor viral infections to affect certain individuals who are thought to be predisposed to becoming ill. In a great many cases, illness in fact results from a deficiency in the body's defenses, the efficacy of which depends on the food ingested each day and



with which the organism renews itself. If it relies on an unbalanced diet the body will naturally be poorly protected and will not be able to defend itself adequately against bacterial or viral attack.

Establishing a Good, Balanced Diet

Our diet has become very unbalanced relative to what is naturally essential for our organism. We often eat too much and inappropriately: too much sugar, salt and saturated fats, particularly at the expense of fruit and vegetables. This leads to excess weight and obesity, a scourge unfortunately becoming more and more widespread in children, the main target of manufacturers of sweets, sodas, hamburgers and pizzas.

The disastrous consequences of childhood obesity for the adult are well known. In the United States the upsurge in cardiovascular diseases and cancers caused by incorrect diet is becoming a real "epidemic," according to statements by health authorities. Obesity has even begun to reduce life expectancy for the first time in the history of the country.

In addition, doctors have developed the habit of readily prescribing many medicinal products to combat repeated colds and sore throats, attacking the consequences and not the causes of the problem. The frequent recurrence of such illnesses in many patients should nevertheless alert medical practitioners to the problem, which is actually structural, due above all to bad dietary habits, and not linked to climate or pollution in cities.

It is essential to teach our fellow citizens to eat correctly again, considering the implications of an unbalanced diet. Poor habits have repercussions for their dental health, both before and after encountering problems.

Giving Up Dietary Excess

A female patient consulting her doctor for digestive disorders or for being overweight is not so much motivated by health as by aesthetic reasons. Putting on too much weight affects the image she has of her body in relation to the models of perfect slimness and beauty impressed on our minds by advertisements, fashion and the media.

It is not just chance that causes many adolescent girls to feel torn between the desire to give in to the consumerist temptation fostered by the food industry and the wish to conform to the models of slimness, or even utter skinniness, displayed each day in magazines and on screens. One minute they stuff themselves with sweets and industrial foods saturated with fats and salt, and the next they think they can compensate for it by creating nutritional deficiencies through excessive dieting, which is often harmful to health and completely ineffective. Rather than bulimia and anorexia, it is better to opt for a varied, balanced diet, combined with regularly practicing a suitable sporting activity.



The Role of Diet in Dental Health

These observations may seem remote from dental problems, but that is not at all the case, for it is to the diet that we should be looking to discover one of the explanations for the good dental health of our prehistoric ancestors, mentioned earlier, whose skulls retain their dentition intact. The nature of the healthy and natural food consumed at that time, and also its physical consistency, must be considered: our prehistoric ancestors had to chew their food well, as it was often raw and therefore harder than the food we consume today.

The fact that nowadays we willingly consume foods that have been softened (mainly by successive cooking, freezing and reheating), as well as food that is often doughy or even liquefied, has had an impact on our dental health and explains the fact that toothless jaws are more frequent now than in earlier times, and in younger and younger people.

The basic reason has to do with chewing (mastication), which has become increasingly inadequate, if not altogether disregarded. The sacrosanct hamburger is a good example of this: the ground meat and soft bread encourage the eater to swallow without chewing.

Well Placed Teeth Throughout Life

The observations and recommendations that follow are intended to help anyone keep his or her teeth intact throughout life, as long as the bones in which they are placed are not deformed and the teeth themselves are squarely in those bones. This is the raison d'être of orthodontics. We are going to show you how to achieve this result, in cases where it has not "spontaneously" occurred, by using the forces exerted naturally by the various constituent parts of the mouth. Our method aims to reestablish correct functioning of these parts so as to naturally reestablish good positioning of the teeth, without having to resort to major and intrusive surgery, the effects of which, in the long term, may prove to be worse than the problems themselves.

BASIC PRINCIPLES

- A: Malformed Dentition is Not a Fatality

Individuals' dentition and, more generally, their facial appearance, varies so much that it is not always easy to know how to define "good" dentition or "correct" jaw position.

The wide variety in facial appearance is usually attributed to the random hand of Nature, and thus to the laws of genetics: each person is said to have his own dentition, just as he is said to have inherited his precise eye or hair color. A protruding chin or the opposite, prominent upper teeth known as "horse teeth," are very often considered to be "natural." When correction is envisaged, it is essentially for aesthetic reasons, as these profiles are considered to be unsightly.

Just as a cosmetics surgeon is called upon to modify some part of the body, the orthodontist is often asked to provide a solution to problems perceived to be more aesthetic than functional, consisting of correcting natural malformation, rather than retraining poor mouth function, due to bad habits acquired.

- B: The Origin of Problems is Essentially Functional

The aim of orthodontics is not just to realign the teeth so that they are straight and consequently pleasant to see, producing a beautiful Hollywood smile with the teeth in a row like piano keys. Its purpose, above all, is to reestablish correct functioning of each of the different parts of the mouth to prevent future health problems, which could prove serious. Aesthetics, here, goes hand in hand with good health, with "correct function" being the common denominator.



Our dentition was not created exclusively to be seen when we smile but to serve the vital function of mastication. Our teeth break down the food we consume and grind it like a mill. Solid, well positioned teeth are needed to perform this function satisfactorily. Yet it is perfectly commonplace to see many of us with receding gums (that is to say, teeth moving within the bony alveolus or socket), teeth with caries and, in the worst cases, teeth requiring extraction or spaces where they have already fallen out —all of which shows that the functions of the mouth are not being fulfilled as they should be.

The orthodontist's role is not therefore limited to fitting braces to mechanically correct the position of the teeth and "straighten" them; above all he must try to identify the dysfunction that has caused the teeth to be poorly positioned and the health problems that have developed as a consequence. What is the point of mechanically straightening the teeth by temporarily fitting a brace if the dysfunction of the mouth has not been corrected? As soon as the brace is removed, the teeth will just move out of alignment again, since the problems related to function have not been resolved.

We know, for example, that the effect of a child habitually sucking his or her thumb hollows the palate, preventing certain teeth from developing normally and sometimes pushing the upper incisors forwards into the position known as "buckteeth." It is obvious that if the thumb-sucking is not stopped, any corrective device will only have a short-lived effect and will not serve any useful purpose.

For the teeth to be straight and well positioned, the many forces at work inside the mouth must be considered as a whole, not individually, the teeth being only one of the components involved, even if they are the most visible. The orthodontist uses the natural forces in the mouth to restore its correct functioning and straighten the teeth.

- C: The Various Functions of the Mouth

The situation is clear: problems generally seen as aesthetic are in fact functional, since they are the result of poor functioning within the oral area. If we want to understand the mechanisms affecting the teeth, the way they are fixed in their sockets and how they wear, we need to consider the main functions of the oral cavity.

Chewing and Swallowing Food

It is here in the oral cavity that food is chewed or masticated (mastication being the action of shredding and grinding food) and swallowed (the action of the ground food passing through the esophagus to the stomach). These functions are the most obvious because we are most aware of them.

Swallowing Saliva

We swallow our saliva on average 2000 times per day without noticing it; this function is virtually automatic and therefore we are not conscious of it, in the same way that we blink our eyes and breathe. We become aware of it when in a moment of emotional stress we notice that our mouth has become dry.

Saliva continually moistens the mouth (just as tears moisten the eyes), even when we are asleep.

Swallowing, when it occurs correctly, leads to pressure between the jaws, involving contact between the upper and lower teeth. This mechanical action has decisive consequences on whether the teeth become correctly or poorly positioned in the jaws.

Speech

The mouth is an important organ of speech.

Spoken language appeared in humans about 100,000 years ago.

We articulate phonemes, the basic sounds from which we form words. We pronounce thousands of phonemes a day, and each of them involves the tongue being in a specific position and then making



contact with the teeth and palate. Each language produces its particular effects on the oral cavity, depending on the particular phonemes that it uses.

It is highly probable that the major cause of the so-called "horse-toothed" dentition of English-speaking people, a physical characteristic greatly exaggerated by cartoonists, is, among other factors, the intensive use of the phoneme “the,” which is produced by touching the upper incisors with the tip of the tongue, producing what the French consider a lisp. The incisors are thus pushed forwards hundreds of times a day, from childhood onwards. The "horse teeth" observed among English speakers cannot be attributed to excessive love for the animal of the same name.

Breathing

This most important vital function normally occurs through the nose (nasal passages). We know that some children do not breathe through their noses because their nostrils are narrow, owing to infections, allergies or growths which frequently block the nasal passages. As the air is unable to pass through easily, such children breathe through their mouths, keeping them permanently partly open, with the tongue low and slightly protruding. This has an effect on the overall functioning of the mouth and consequently on the way the teeth develop.

Facial Expression

Facial expression is also one of the functions of the oral cavity, as our mouth allows us to communicate our emotions and reactions. Depending on our dentition we may have a wide, toothy smile or a thin-lipped or crooked smile. We can even make our emotions visible by moving our cheek muscles.

These many functions are related to the complex organization of the oral cavity. The latter has no less than 34 joints: these are the joints of the 32 teeth in the two jaws and the two temporomandibular joints, i.e., the joints connecting the mandibles to the rest of the skull in the temporal region. Besides these 34 joints, the mouth includes a large number of muscles, with the tongue alone having seventeen. The oral cavity also provides communication with the external environment (via the lips). The cranial nerves are nearby and can be the cause of all sorts of pain or neuralgia.

For the teeth to be well positioned and able to carry out their functions correctly, all the elements of the mouth must be taken into account as a single unified functioning unit.

Apart from problems of genetic origin, there are two primary causes of most problems concerning tooth position, both linked to bad habits:

- Inadequate swallowing

- Poor tongue posture

- D: The Importance of Swallowing

When we swallow, the food bolus (the chewed food) and the saliva pass from the oral cavity into the esophagus and stomach to be digested. Surprisingly, the way we swallow may be the root of dental problems.

Swallowing consists of two distinct phases:

- The food/saliva is conveyed onto the tongue—a conscious, voluntary movement.

- The food/saliva is evacuated by the tongue into the esophagus— an unconscious reflex.



While swallowing food is an intermittent process and happens at particular times, evacuating saliva is a continuous process. The salivary glands constantly produce saliva, so that as a result, swallowing continues even during sleep.

Individuals swallow in different ways, depending on whether they have teeth or not (babies, for example, and elderly people who have lost their teeth).

There are two types of swallowing in humans:

- Suction swallowing (infantile swallowing)

- Mature swallowing

Suction Swallowing in Babies and Toothless Elderly People

This is essentially the way small babies swallow. It is explained by the fact that babies have no teeth and consume an exclusively liquid diet. Infantile swallowing is important not only for feeding purposes but also for promoting the development and growth of the lower jaw, which is mobile, the upper jaw, or maxilla, being fixed. The baby needs a sufficiently long sucking time to make his or her lower jaw “work,” which is achieved when he or she is breastfed.

In contrast, bottle feeding takes much less time because the milk is sucked out and drunk more easily, which explains why the baby compensates by sucking his or her thumb or a pacifier given for the purpose.

An infant swallows by contracting his cheeks, projecting his tongue forwards and sucking with his lips. Toothless elderly people who can no longer chew return to these baby reflexes to consume food which, of necessity, comes in liquid form.

Mature Swallowing in the Older Individual

This is normal adult swallowing and develops as the teeth take their place in the oral cavity. At the same time, food becomes more and more solid, requiring chewing before being swallowed.

The mastication needed for solid food is an important function for correct dental equilibrium since it is the only time the teeth exert considerable force, in order to grind and soften the food before it is swallowed. During this process, as long as the teeth intercuspate correctly and the temporomandibular joints are properly aligned, the food is crushed by the molars acting like a mill.

While the food is being crushed, a special reflex comes into play called the proprioceptor reflex (specific to muscles), which prevents the teeth from striking each other, so that it is only when swallowing itself occurs that the upper and lower teeth come into direct contact with each other, providing a necessary leverage point for the tongue, to assist swallowing.

While this is occurring the teeth are subjected to a strong vertical force, the consequences of which are vital for the health and solidity of the teeth. This pressure, correctly exerted, strengthens the periodontal tissues (those connecting the teeth to the bone), particularly the ligaments that surround the roots of the teeth and connect them to the bone of the jaw.

In mature swallowing, the lips and cheeks do not participate in the movement in which the food/saliva from the oral cavity passes into the esophagus. Everything occurs inside the mouth, which is like a closed box: the teeth are clenched and the tongue sucks up the saliva while pressing against the palate, occupying the whole area without coming into contact with the teeth (particularly the incisors). The tongue alone draws the food/saliva into the depression created in its centre, triggering the muscular swallowing reflex. The movement of the food bolus downwards is evident as it passes the "Adam's apple," which makes an up-and-down movement during swallowing.



The Importance of Mature Swallowing for the Teeth

Mature swallowing plays a decisive functional role in dental equilibrium. Indeed, every time we swallow saliva or eat, the repeated pressure exerted on the teeth produces two positive effects:

- It stabilizes the teeth by strengthening their establishment in the sockets of the bone. - It stimulates blood circulation in the gums and periodontal tissues.

Natural development in the growth of any individual means that infantile swallowing becomes mature as the teeth develop and solid food gradually replaces liquid food.

Only mature swallowing ensures a harmonious balance in a mouth containing teeth.

However, there are many people who, at an age when the swallowing process should be mature, for various reasons, including heredity, but particularly related to bad functional habits, continue to swallow by suction—they habitually sucked a thumb, finger or pacifier until quite late, consumed lollipops during adolescence, have a lisp, etc. There can be many consequences of poor swallowing habits such as caries, teeth that loosen, bleeding gums, etc. Grinding the teeth while sleeping and wearing them down, known as bruxism, is probably due to poor swallowing of saliva associated with a badly positioned tooth. Since the upper teeth cannot properly exert pressure on the lower ones during swallowing, the circulation of blood in the gums and around the roots of the teeth is poor and the subject compensates, as it were, by making the uncomfortable tooth or teeth work. The blood circulation is reactivated by grinding the teeth, but they suffer abnormal wear.

- E: The Flesh Sculpts the Bone and Positions the Teeth

To understand everything that happens in the oral cavity, we must first be aware that it is the soft tissues (the tongue, lips and cheeks) that control the hard tissues (the bones, teeth), and not, as is generally thought, the other way around. This has actually been known for a long time. Did not Lao-Tzu say, "The soft overcomes the hard, the weak overcomes the strong"? Did not La Fontaine compare the solid oak tree to the supple reed? In fact, this phenomenon is very broadly applicable. We know for example that the orbit without its eye will close up and be reduced to the size of an eye of a needle, as I was personally able to witness in India in a young blind beggar.

By their slight but constant and continual action, the muscles of the tongue and cheeks and the position of the lips have an effect on the position of the teeth, just as, day after day, the water traces the bed and banks of a river, eroding the hardest of soils. The sinuous nature of the flow of water causes the formation of meanders: the phenomenon, hardly begun, is amplified by erosion (hollowing) of the concave bank and silting up (refilling) of the convex bank. Water sculpts shorelines and mountains through its physical and chemical action on rocks. The same is true of all fluids including the wind, with its effect on vegetation, shaping even the largest trees, or on the hardest of rocks.

Identical natural processes are at work inside the mouth. There is no doubt that the muscles forming the tongue fundamentally control how the teeth are positioned, so that we can say without exaggeration that most dental problems occur through poor use of the tongue, from which it follows that, in the particular case, the tongue is badly positioned. This explains why restoring correct posture of the tongue in the oral cavity is necessary and will usually be sufficient to permanently correct the position of the teeth.

The teeth take up their positions according to the muscle forces exerted around them. They find a "neutral", or, even better, a "neutralized" position, that is to say, a point where opposing muscle forces acting on them cancel each other out. Each tooth thus assumes a position of equilibrium and occurs at the point where the forces exerted by the fleshy parts of the mouth have placed it. This is an individual equilibrium, individual to each tooth, since there are a great many complex forces acting within the mouth.

The teeth have to be mutually interdependent for the functions they fulfill to be properly performed and for the entire dentition to be firmly and permanently established. If everything is to function



correctly, there must be overall equilibrium throughout the oral cavity, not just as concerns the position of one specific tooth.

For the environment of the teeth to remain stable, they must only be subjected to vertical forces, namely the forces of mastication and swallowing. In these conditions the mandibular and maxillary bones (the jawbones) and the periodontal tissues (the connective tissue attaching the teeth to the jawbones) are able to become strong and create suitable conditions for a set of solid, healthy, stable teeth which are well aligned, vertical, close together, with no open bite, and which, in addition, but less importantly, are aesthetically pleasing.

To sum up, the shape of the jawbones and the position of the teeth results from the pressure exerted by the functional forces produced by the various groups of muscles which make up the oral cavity:

- The cheeks, with the zygomatic muscles in particular, which, for example, pull the mouth backwards and allow us to smile

- The tongue, the real orchestra conductor of the mouth

- The lips

- The chin muscles, known as the mentalis muscles

- The pharynx

- The masseter muscles which raise the mandible, particularly to close the mouth

- The medial pterygoid muscles which move the mandible for mastication These muscles are the most powerful in the body. It is the tongue, however, which is the real conductor of the oral cavity's orchestra.

- F: The Key Role of the Tongue in the Way the Mouth Functions

The "Orchestra Conductor" of the Mouth

Some people wrongly think that the position of the teeth determines the position of the tongue in the mouth but, on the contrary, it is the tongue that plays the most important role in positioning the teeth. The tongue is very much the "conductor of the oral orchestra." It is so powerful that it can cause dental or even bone deformities when used incorrectly.

To discover how the tongue is being used in a particular case, it must be examined at rest to see whether it rests between the upper and lower teeth on one side, or on both sides at once, at the front or throughout the entire length of the dental arches. Its position (whether low, centered or even high in the mouth), its volume (whether thick, pointed or flattened) should also be observed, as well as whether the insertion of the lingual frenulum is towards the front or not. If the lingual frenulum is inserted too far forwards, movement of the tongue is greatly reduced: it can only move at the bottom of the mouth, and from back to front, causing the lower jaw to move forwards as a consequence (prognathism).

The behavior of the tongue must also be observed as it functions in order to assess whether its mobility is strong or normal, how far it extends over the dental arches (to the side, to the front, and over the entire arch), and its position when swallowing saliva. Interposition of the tongue at the side prevents the teeth from developing completely (they do not fully erupt), which leads to the height of the molars and premolars being inadequate and the incisors being excessively covered (supraocclusion). At rest, since the teeth do not intercuspates, the space left free between the upper and lower molars increases, allowing the tongue to occupy it.

Thrusting the tongue forwards between the teeth (sticking one's tongue out) can deform the mandible due to torsion, and sometimes leads to open bite of the incisors, with cessation of growth of the alveolar bone (the bone holding the teeth).



Its Role in Articulating Words

When we speak, the tongue is positioned in a way that is almost identical to its position when we swallow. Articulating sounds is therefore affected if tongue posture is poor.

To pronounce the dental sounds ([d], [t] and [n]) the tongue must not touch the incisors: just a small area of the tip of the tongue must be raised and touch the palate behind the incisors. There is a hiss when the tongue is interposed at the sides.

For the sibilants ([s], [z]), the tongue must not be in the middle between the two arches, but must remain still, at the bottom in the lower arch.

Its Role in Swallowing

Let us recall, first, that there are different forms of swallowing depending on whether or not the oral cavity has teeth. Infants and edentulous elderly people do not swallow in the same way as young children or adults (see below).

There are several indications that an individual is swallowing in an adult manner. Firstly, the cheeks must not relaxed when saliva is swallowed; secondly, the lips, regardless of how thick or thin they are, should come together when at rest and have normal tonicity; and finally, when swallowing, the lips should be relaxed and touch without effort.

In contrast, swallowing in the older individual is atypical, still resembling that seen in the infantile stage, when the lips are strongly contracted, as an effect of residual original suction, or quiver slightly. At the same time, contraction of the chin muscles can be seen, with abnormal swelling of the sublabial muscles. Indeed, the purpose of contracting the lips is to accumulate saliva behind the incisors in order to apply suction, using the tongue in the same way as a baby does when sucking at the breast. Tartar deposited behind the lower incisors is a clear sign of swallowing that has remained infantile. If the lips were to be separated during this type of swallowing, it would be seen that the teeth are not closed together as they should normally be and that the tongue is thrust forwards.

Adult swallowing should occur without any movement other than that of the tongue, which moves up and down, and the masseters, which contract; the molars should remain in contact.

Its Role in Breathing

Normal breathing takes places through the nose (nasal breathing), but a large number of individuals breathe through the mouth (mouth breathing). This is the cause of many problems often considered to be of unknown origin, such as a dry mouth when sleeping, sleep disturbed by frequent waking, allergic rhinitis, snoring and sleep apnea.

Mouth breathing is caused by hindered nasal breathing, due either to the presence of adenoid growth resulting from repeated infection or to having a palate that is too deep or too narrow, which decreases the volume of the nasal fossae. The quantity of air drawn in via the nose is not sufficient for pulmonary ventilation.

A deep palate may be the consequence of sucking a thumb or finger, but also the consequence of

high tongue posture at rest, and therefore also when functioning. This posture can be corrected by wearing a device that forces the tongue to occupy a lower position. With the tongue retrained the palate is remodeled; air passing through the nostrils helps enlarge its own passage and is filtered by the hairs in the nose, thus improving allergic rhinitis.

The same applies to too narrow a palate, which is easily treated with a Quad Helix (see chapter VII) or a Tongue Right Positioner, thus improving nasal breathing and correct posture of the tongue.

Once nasal breathing is reestablished, sleep problems disappear, providing relaxation and a sense of well-being. Colds are less frequent and allergies subside.



- G: Voluntary and Unconscious Movements

Malocclusion becomes apparent when an individual closes his teeth and the two jaws, fitting poorly together, leave an open bite or exhibit imperfect intercuspation or interlock between the upper and lower teeth. Many of these cases of malocclusion originate from abnormal neuromuscular functioning of the mouth. The results of treatment to reestablish good occlusion will only be sustained if corrective dental devices are fitted associated with retraining sessions to correct the muscle behavior at fault, which is almost always the source of the problem. The difficulty is that these incorrect behavior patterns will have been present from birth and have therefore become unconscious.

Nature provides for the neuromuscular activities of the mouth and face to be present from birth so that the infant can survive by being able to breathe and consume food (sucking and swallowing his or her mother's milk). Studies have shown that these neuromuscular reflexes appear in the fetus at 11 weeks for the nose/mouth region and at 16 weeks for breathing movements. At about 29 weeks, stimulation of the mouth already provokes sucking movements.

When a baby is born, the tactile acuity of the lips and tongue is already highly developed. The tongue extends beyond the toothless jaws and projects between the lips. The infant will follow a finger that touches his lips with his mouth; indeed his entire relationship with his environment is via his mouth, pharynx and larynx. These parts of the body are the site of a very high concentration of nerve receptors. When stimulated, they pass information to the brain, which regulates respiration, sucking and the position of the head and neck during breathing and breast-feeding. At this stage, the tongue and lips are the most sensitive reflex area of the body and many external sensory signals are concentrated here.

Later, with acquisition of mastication and spoken language, development of the neuromuscular functions will be determined by the teeth. Mastication becomes mature therefore when the incisors come into contact and stimulate the muscles that control the position of the jawbones. When the upper (maxillary) and the lower (mandibular) incisors begin to touch, the jaw musculature gradually adapts how it functions to the arrival of the teeth. Since the incisors erupt first, the mouth acquires its closure position from the front towards the back following the direction of suction, before closing laterally when the premolars appear at the sides of the mouth.

The child thus learns in stages to shut his mouth, or acquire his occlusal functions. There is a cause and effect link between maturation of the central nervous system and maturation of the musculature of the face, mouth and jaw. The development of the jaws and dentition is synchronized, with the first mastication movements being irregular and still poorly coordinated. When the first dentition (the milk teeth) is complete, mastication stabilizes and becomes increasingly effective as foods offered become more solid, but it is only when the deciduous molars are present and making contact that true mastication movements appear and mature (adult) swallowing replaces infantile swallowing.

The young child stops feeding from the breast and begins to learn to talk and express himself. This transition, which takes several months, is helped by the maturation of the neuromuscular components. It has usually been completed by the time the child is about two years old. The change which has to take place is considerable, because the mature swallowing process is virtually the opposite of the infantile process: the jaws are brought together, the end of the tongue is drawn back and no longer touches the front teeth or those at the side, and the lips are relaxed because they no longer play the active role they had in sucking.

When this transition fails to occur or is only partial, the result is "atypical swallowing." In this case the orthodontist does not simply have to retrain the patient, but has to teach him a movement that he has not naturally acquired. In particular, the tongue must remain supple and immobile. It normally "knows" what it has to do to swallow if the environment is correct. The muscles connecting it to its bony base have to be sufficiently developed to allow it to move so that chewed food is carried towards the esophagus. This also applies to the muscles that control vertical movement of the lower jaw (the only mobile jaw) and allow mastication, and, moreover, provide the tongue with support as it performs its backwards swallowing movement. Closing the teeth together is normally enough for this movement to occur.



Just as singers, for instance, keep their tongues in a low position to allow sound to pass, actors are taught to articulate clearly by making them talk with a pencil between their teeth to keep the tongue relaxed and in a low position. The tongue should only move in the mouth to pronounce the dental consonants ([t], [d], [n] and [1]).

- H: An Attractive Profile: the Decisive Role of the Lower Incisors

The position of the lower incisors is decisive for the profile and therefore for treatment too, because the upper jaw fits over the lower jaw, enveloping it. Because the tooth and the bone form an interdependent unit, the lower incisors must be stable, so that the forces arising during mastication do not put a strain on them but rather strengthen them. Once the lower incisors are stable, the upper incisors must fit in front of and slightly overlap them to properly fulfill their role as scissors, cutting and "incising" food, hence their name.

The profile should be straight, with the upper and lower lips well defined and displaying slight concavity. The nose and chin are included in the profile.

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It is clear that the aim of orthodontic treatment is to obtain correct occlusion, with the teeth coming into contact properly when the jaw is closed, that occlusion stabilizing over time with the teeth firmly in place. Occlusion is not a purely mechanical phenomenon, but the result of diverse, discontinuous and dynamic forces acting in particular on the teeth. The growth of bone, the force of muscle contraction during mastication and the natural tendency of teeth to move are decisive factors. Finally, functions performed abnormally can influence the shape and direction of growth of the facial skeleton and skull, and therefore even the physical appearance of the face.

The volume of the soft tissues and the way they function depend on the brainstem of the central nervous system, which induces unconscious mouth reflexes. The latter are inherited, as has been shown by the most recent discoveries in the field of embryology. Indeed, the genes which control these reflexes in particular are present from the third week of embryonic life and are inherited from the parents. Nevertheless, heredity is not a fatality, because tissues are continually being renewed

A long face should have a flatter profile, with the incisors positioned further inwards, whereas a square face can take incisors more inclined towards the exterior so that the lips are more visible in profile.

Long face Square face

Position of the lower incisor depending on whether the face is long or square



during the course of existence. We know, for instance, that the body's entire store of calcium is completely renewed in less than three months.

It follows from this perpetual activity that while incorrect functioning of the tongue, cheeks and lips may ideally be corrected during the period of growth, it may also be rectified after the growth period, since tissue remodeling is a process that occurs throughout life.

Everything is dependent on continual remodeling of the hard tissues (bones and teeth) by the soft tissues (the tongue, lips and muscles of the mouth and face) with which they are in contact.

Normally, when the muscle forces of the mouth are balanced, the teeth will grow straight and perpendicular to the bony base. However, lips exerting too much pressure on the teeth (excessive labial force) will push the incisors inwards, and, conversely, a constantly moving tongue thrusting forwards will push the incisors and sometimes even the jaws forwards.

As surprising as it may seem to the non-specialist, the functioning of the tongue has considerable impact on the position of the teeth and the shape of the face. The resulting deformations create particularly what are known as facial disharmonies: endognathism, retrognathism, prognathism, etc. Deformations to the front or rear, in width or height, are again functional, and may have serious consequences for oral health in general unless they are corrected in time. These malformations depend on the point of application of the harmful forces in question (the precise point of action in the mouth) and on their intensity and duration.

It is easy to see that the problems posed are not simply aesthetic: the harmony or disharmony of the jaw is only a visible reflection of the state of dental health, intimately related to the good or poor functioning of the different components of the mouth.

Aesthetics is the tip of a much larger medical iceberg than it was first perceived to be.

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CHAPTER II: PROGNATHISM

Prognathism is deformation of the basal bone, causing the upper and/or lower jaw to project forwards abnormally. The jaws are therefore no longer aligned one with the other, one of the two being offset forwards.

Forward projecting teeth (alveolar protrusion) or the opposite, posteriorly projecting teeth (alveolar retrusion), may be added to this problem, complicating still further the orthodontist's task of correcting the position.

- A: Prognathism, Alveolar Protrusion and Retrusion

Of the Upper Jaw or "Horse Teeth"

This results from excessive pressure of the tongue on the upper jaw. When the tongue also exerts strong pressure on the upper incisors, the alveolar bone, which holds the teeth in the jaw, projects too far forwards. Alveolar protrusion, (also known as labioversion) of the upper incisors is added to the maxillary prognathism, so that not only does the upper bone project forwards, but so do the teeth.

An abnormal space is created between the upper and lower incisors: the upper incisors are long and protrude from their alveoli because there are no antagonist teeth with which they are able to make contact. The lower incisors rest against the palate instead of against the upper incisors. Because they are thus weaker, these teeth loosen in adulthood, and a child will not use his incisors because they are sensitive, preferring to cut up his food with his side teeth.

Damien P

Interposition of the lower lip exerts pressure on the lower incisors, which are pushed backwards. While the chin has continued to grow, the mandibular incisors are obstructed and

rest against the palate. The maxilla markedly protrudes and the upper incisors rest on the lower lip. The space between the teeth equals the thickness of the upper lip.

If, in addition, the lips are very tonic and strong, the upper incisors can be pushed back inwards so that the canines, the last teeth to emerge in the anterior part of the arch, erupt very high in the gum or may not even be able to emerge at all (they are "impacted"). The lateral incisors pivot sideways due to lack of space, and the central incisors more or less completely cover the lower ones, resting against the lower gum. The upper arch is caught between two powerful muscle forces. In such cases upper alveolar retrusion complicates the maxillary prognathism: the top bone protrudes while the corresponding incisors incline inwards.



Example of a smile showing the gums; the upper incisors are inclined inwards, but protrude; they completely cover the lower incisors, so that the smile line has moved downwards.

The roots of these incisors become prominent and deform the bone of the maxilla at the base of the nose, pushing it forwards (the gums become clearly visible when smiling).

Françoise G: Before treatment After treatment

Xavier P: Before treatment

Françoise G



In the case of Françoise G. (above), it was not possible to put the canine back into place because of fears of serious damage, surgery proving to be impossible. The canine remains within the palate. The root of the lateral incisor was being worn away by the development of the canine, but the treatment undertaken should allow it to be repositioned.

If the lower lip is interposed between the upper and lower incisors, mandibular alveolar retrusion is added to the maxillary prognathism: the maxillary bone projects, while the lower incisors are abnormally directed towards the interior of the mouth.

Isabelle S.

Françoise G: Before treatment After treatment

The face is long, the upper lip short and the chin long. The maxilla protrudes a long way: the distance between the upper and lower incisors is 12 mm, which is the same as the thickness of the lip interposed between the teeth. The premolars must be extracted in order to pull the upper incisors back and put them in the correct position.



The lower incisors rest against the palate. Maxillary labioversion and supraclusion can be observed in cases where the mandible is small. The growth of the mandible is slowed by the lower incisors which rest against the palate. To make contact possible between the two jaws, the mandible is

subjected to torsion. It must be freed so that its growth can catch up with that of the maxilla. This is possible here, as growth has not been completed.

In the case below, of Damien P., the distance between the upper and lower incisors was 1.4 cm. Treatment consisted of slowing the growth of the upper jaw while freeing the growth of the lower jaw and decreasing the height of the incisors by retracting them into the bone.

It was also necessary to retrain Damien's swallowing function; he sucked in his lip each time he swallowed, abnormal behavior that was responsible for the difference in bone growth between the two jaws. A banding appliance was fitted for 18 months to exert forces in opposite directions. Less than 4 mm of mandibular growth was obtained, with equivalent shortening of the maxilla, which thus became correctly superimposed over the mandible, with the teeth correctly positioned. The profile obtained was good, as the after-treatment photos show.

Damien P: Before treatment After treatment



Damien P: Before treatment After treatment

Of the Lower Jaw or "Protruding Chin"

This results from excessive pressure of the tongue on the mandible.

If the upper molars are posterior to their normal position, compared with the lower teeth, the upper incisors will also be behind those of the lower jaw. This is mandibular prognathism: the chin is prominent, forming a "protruding chin.”

The growth in length of the maxilla (and sometimes even its width) is impeded by the mandible, which, because of its mobility, is able to encircle it.

Stéphanie L.

The growth of the upper dental arch is completely hampered by the mandible, both

transversely and in the anterior-posterior direction.

The upper teeth overlap through lack of space (dental crowding), while the lower teeth develop normally and line up correctly without hindrance.



As in maxillary prognathism, mandibular labioversion can occur with mandibular prognathism: both the jaw and the lower incisors protrude.



Before treatment After treatment

A protruding lower jaw is not only unattractive but also functionally deficient. The tongue moves at

the bottom of the oral cavity and to the front of it and the teeth are positioned beyond it. Growth of the maxilla must be encouraged to reestablish normal function.

Alveolar retrusion does not occur with mandibular prognathism because the lower lip does not exert the same force as the upper lip. It is incapable of pushing the lower incisors inwards into the oral cavity.





- B: Labioversion without Prognathism

In this case, the malformation only involves the teeth and the alveolar bone, not the basal bone (as is the case in prognathism). The teeth may protrude abnormally in the upper jaw (labioversion of the maxillary incisors), in the lower jaw (labioversion of the mandibular incisors), or in both jaws at once (double protrusion of the incisors).

Only in the Lower Jaw (Labioversion of the Mandibular Incisors)

Before treatment

Before treatment

After treatment

The upper incisors project forwards by 18 mm, the thickness of the lip. Their growth is not curbed by

the lower lip. Treatment reduces this difference and repositions the incisors correctly, the upper

incisors resting against the lower ones, without completely covering them.



Only in the Upper Jaw (Labioversion of the Maxillary Incisors)

This problem is entirely functional in origin, i.e., lingual, meaning that the tongue exerts too much pressure on the lower incisors.

In Both Jaws at Once (Double Protrusion of the Incisors)

There is no bone deformity but rather a lack of bone at the base of the nose, which makes it appear flattened. The problem only involves the alveoli and the teeth they contain, which project forwards. This is the "Asian" profile. Appropriate treatment, pulling the incisors back to the correct angle, refines the nose, as the photos below show.

Bernadette N: Before treatment



Sometimes the four premolars need to be extracted before the actual

Sometimes the four premolars need to be extracted before the actual orthodontic treatment

can be undertaken to obtain substantial straightening of the incisors and the resulting

modification of the profile.

Bernadette N: After treatment

Van N: Before treatment



In the case of young Van N., banding treatment and retraining produced excellent results after the four premolars had been extracted. The wisdom teeth, once they emerge, will be retained and will hold the entire dentition of the two arches in place, stabilizing the straightened incisors.

Before treatment

Before treatment

After treatment

Advancement of the maxilla affects both the basal and the alveolar bone. If treatment is

initiated early enough, it is possible to take advantage of growth, stimulating it in the mandible

and curbing it in the maxilla.

Van N: After treatment



CHAPTER III: WIDTH DEFORMITIES

These deformities affect the upper jaw, originating in the bone rather than the teeth. Since the teeth, however, are attached to the bone, they follow the deformation it sustains. Such deformities are also linked to incorrect tongue or lingual function.

- A: Upper Molars Wider Apart Than Lower Molars (Maxillary Expansion)

Maxillary expansion occurs when the palate is wide as a result of having been shaped by a large tongue exerting pressure all around the upper jaw. The maxilla develops too greatly in width so that the first upper molars "articulate" (are sited) lateral to their normal position.

As the above diagram shows, the upper teeth are to the outside of the lower teeth, the upper jaw being wider than the lower. The consequences on how the mouth functions are generally significant. Not only are the upper incisors pushed forwards excessively, but the upper molars, being wider apart than the lower ones, are no longer in occlusion with them, i.e., they do not intercuspate to fulfill their grinding function. Chewing and crushing food is not possible, which may lead to significant digestive problems.

Palate

Huu Hoa

The upper arch is wider than the lower arch: it is impossible to chew because the molars do not

make correct contact.



Huu Hoa

- B: Upper Molars Not as Wide Apart as Lower Molars (Maxillary Contraction)

In contrast, when the tongue does not fill the entire volume of the palate during swallowing, it does not exert sufficient lateral pressure on the walls of the upper jaw. Maxillary contraction ensues, with the result that the palate narrows and the upper molars are positioned to the inside of the lower molars, whereas normally the upper dental arch circumscribes the lower.

Contraction may be unilateral, involving only one side of the jaw, or bilateral, involving both sides.

Palate



The palate is narrow; only one side is affected and articulates to the inside of the

lower molars. The midline between the incisors is off center and misaligned,

producing repercussions on the temporomandibular joints

After treatment

The tongue functions low in the mouth and does not shape the palate, which remains

small and narrow. The upper molars and premolars articulate to the inside of the

lower molars. The narrow palate is circumscribed by the mandible at the sides, and

the detrimental transverse pressure exerted on the molars causes them to loosen.

Séverine F: Before treatment After treatment

Thierry P: Before treatment




Since the palate remains narrow and deep, breathing difficulties may develop.

Florence F, 11½ years old: Before treatment

Florence F, 11½ years old: After treatment

The palate of this 11½-year-old girl, Florence F., resembled that of a 3-year-old child. The lateral incisors were hardly visible, the canines had not had enough space to erupt and the premolars had not developed. The milk teeth were still present and the tongue was spread out between the upper and lower jaw. The gums were swollen by the presence of tooth buds that had not erupted because of lack of space.

Treatment consisted of extracting the extremely damaged first molars, then fitting a Quad Helix (see chapter VII) to enlarge the palate. Subsequently, a banding appliance was fitted. Surgery to the canines allowed them to erupt. Retraining, with fitting of a directional appliance, completed the treatment.

In expansion, as in contraction, chewing cannot occur normally, that is, vertically, because the teeth do not make correct contact (they are misaligned). The individual compensates for this problem by chewing horizontally, as ruminants do. The forces then exerted on the molars are transverse and cause shocks that weaken the teeth concerned. In the adult, the molars are damaged and the very joints of the jaw may be altered. Untimely clicking sounds and pain develops, which, in the most serious cases, can prevent the person from opening his or her mouth.



CHAPTER IV: VERTICAL DEFORMATION OF THE FACE

Examination of the face and the position of the teeth in the bone must take into account the type of facial growth, which may be vertical (long face), horizontal (square face), or normal.

In the absence of treatment, the shape of the face is not modified during growth because it remains subject to the same forces: growth occurs by bone deposition and resorption, so that the shape is maintained the same throughout growth, rather than being inflated like a balloon.

Forces exerted during growth

- A: Long Face (Vertical Growth)

When the length of the face is considerable, or excessive, the lower jaw grows downwards and posteriorly, while the upper jaw grows forwards. There is a constant discrepancy between the two during growth and, as a consequence, the angle between them is abnormally open.

When the face is long and in addition, the incisors are slightly prominent, the facial profile also becomes pronounced, almost horse-like.



Before treatment



This type of deformation can nevertheless be treated by moving the lower incisors backwards so that the chewing forces are exerted vertically on the bone base.

After treatment

The angle of the lower jaw is very open. A long face requires incisors which are retracted, to avoid

having a face like Fernandel's, the French comedy star.

An excessively long face may be inherited but may also be due to tongue dysfunction and finger sucking, which exert a vertical force and consequently cause torsion of the lower jaw. In this case, while the upper jaw grows forwards, the lower jaw grows downwards, producing a discrepancy between the two and deforming the profile: the upper jaw projects while the lower jaw is retracted.

- B: Square Face (Horizontal Growth)

When facial growth is horizontal, the lower jaw grows forwards to an excessive extent, becoming square. It is strong, as is the chin, which protrudes, and the masseter muscles (which open and close the mouth).



This type of deformation can also be the consequence of the tongue being interpositioned over the sides, which slows the growth of the teeth. Incomplete eruption of the teeth causes the jaw to close more tightly, giving the impression of a flattened face. The teeth become worn and tooth grinding (bruxism) sometimes occurs during sleep.

Treatment consists of avoiding interposition of the tongue by functional retraining, and also of positioning the lower incisors to protrude slightly (with slight labioversion), to allow the teeth to withstand the forces involved in chewing.



CHAPTER V: GENETIC ABNORMALITIES

- A: Agenesis

Agenesis (in orthodontics) is the total absence of a tooth bud for a permanent tooth and the persistence of the corresponding deciduous tooth (the "milk tooth"). Instances of agenesis are generally hereditary and may involve several teeth (up to 12 or more, counting the buds of the wisdom teeth). In the majority of cases this problem concerns the lateral incisors and the wisdom teeth.

Normally, the roots of the relevant deciduous teeth are resorbed over a longer or shorter period of time, leading inevitably to the milk teeth falling out. If tooth buds are missing, the milk teeth are not replaced by permanent teeth. It is best to anticipate the situation by closing the space that will result by orthodontic treatment. The other solution is to fit implants.

Audrey P: After treatment

In the case of Audrey P., the buds of the two upper lateral incisors and a lower molar were absent and the two central incisors were very widely spaced. The treatment was designed to compensate for the lack of these teeth by closing the spaces through fitting a banding appliance. The empty spaces for the missing lateral incisors were filled by the canines, which were ground into the shape of incisors.

Owing to the banding treatment the premolars and molars could also be moved towards the front. The emergence of the wisdom teeth in due course will help establish an overall equilibrium, and the end result of the treatment will be aesthetically pleasing.

Audrey P: Before treatment: agenesis of the lateral incisors



- B: Supernumerary Teeth and Odontomas

The difference between supernumerary teeth and odontomas is that the former arise from normal tooth buds and are tooth-shaped, while the latter arise from abnormal buds and are not tooth-shaped. The origin of these extra teeth is often hereditary and the abnormality concerns particularly the incisors (upper and lower) and the wisdom teeth. Supernumerary teeth may interfere with the development of adjacent teeth, and several such tooth buds can be found in a single mouth (Crouzon's disease), although this is quite rare.

- C: Microdontia

Microdontia refers to the condition in which the teeth are too small to occupy all the space available on the jaws. When this condition affects the upper lateral incisors, they become pointed and round and detract from the attractiveness of the smile.

- D: Crowding

Crowding, or disharmony between tooth and jaw size, is basically due to the size of the teeth being too great for the bones that support them (i.e., the two jaws).



This problem is of hereditary origin, a child possibly inheriting tooth size from one parent and jaw size from the other. The jaw may thus lack sufficient space for all the teeth to erupt and assume their correct positions. The teeth overlap and/or erupt too high (or, for the lower jaw, too low) in the gum.

The case above shows that the canines have emerged high in the gum because there was not enough room, and that the lower incisors impinge on each other, and have also erupted low in their gum.

Richard R: Before treatment

This is more or less the same as the previous case. The canines are prominent and have not developed in the axis of the milk teeth canines because of lack of space.

Crowding can be easily corrected by extraction: the teeth chosen by the practitioner are removed to make room and reconstruct a harmonious dental arch, which inevitably will contain fewer teeth. The teeth removed are often the premolars and the remaining teeth are positioned correctly using various techniques, such as fitting corrective devices and functional retraining. The aim is to achieve good intercuspation (the posterior teeth fitting together well), with the incisors properly positioned on their bone base, the midline of the two jaws in alignment, facial symmetry, etc., and an attractive smile.

Claudette G: Before treatment After treatment



- E: Impacted Teeth and Wisdom Teeth

Impaction of the Upper Canines

The upper canines are the last teeth of the smile to appear. If the tooth buds (embryo teeth) do not grow in the normal position, they may cause more or less serious problems such as the root of the adjacent tooth being displaced, with the lateral incisor then slanting forwards or backwards.

Cécile E.

One of the lateral incisors has been pushed out of place by the canine tooth bud. Surgery will

be necessary to straighten the canine bud and extract the canine milk tooth.

If there is enough space for the canine, the tooth bud can be correctly repositioned by surgery. Banding treatment will then align the dental arch properly.

On the other hand, if there is insufficient space for the impacted canine to emerge, two premolars must be extracted, one on the right and the other on the left, to produce symmetry. As it grows, the canine will take up the space left by the premolar.

In other cases, the canine can destroy the root of the lateral incisor and cause its loss or at least cause its crown to be worn down.

The problem can be even more complicated when there is considerable lack of space and the canine tooth bud is crooked. In this case, the premolar must first be removed, then the canine tooth bud straightened. An orthodontic bracket must be attached to the space cleared on the crown of the impacted canine, and traction applied, using a fixed device, to position it in its normal place.



Impacted canines: The two canine tooth buds are developing behind the roots of the incisors. Surgery

will be necessary at the same time as the two premolars are extracted.

Marie-Agnès M: Before treatment

Marie-Agnès M: After treatment



Wisdom Teeth

The third molar is known as the "wisdom tooth." Its late appearance, though not abnormal in itself, can cause problems when space is lacking for its development. It must then be extracted. However, if the wisdom tooth is healthy, the first or second premolar may be extracted instead, if it is damaged, highly reconstructed or devitalized, to free space for it.

Another solution is to remove the second premolar if, by doing so, sufficient space can be reclaimed to allow the wisdom tooth to grow properly.

Sometimes there is sufficient space for the wisdom tooth, but its tooth bud is crooked. Rather than extracting it, it can be straightened to allow the tooth to grow in the right place.

- F: Cleft Lips

Harelips or cleft lips and palates are due to damage to the fetus during development. Clefts may be in the palate or lip, or both.

In cleft palate, the palate is not completely closed at birth, and the mouth and nose communicate. In dental terms, a tooth bud is lacking in the cleft and the tooth buds round about appear randomly placed.

It is essential to first perform surgery on the bone. Carried out very soon after birth, it closes the communication between the palate and the nose. To avoid the palate retracting as it heals, a small palatal obturator should be inserted, which will be modified as growth progresses.

Later, the actual dental treatment will cause the teeth to fill the gap and take up their normal positions.



Sébastien F: After treatment

As can be seen in the case of little Sébastien F., the teeth are badly positioned. They are rotated 90° relative to their normal position. In addition, this malpositioning of the teeth is maintained by poor tongue position and the manner of occlusion (closure of the mouth). Development of the tooth buds either side of the cleft is totally disordered, and a lateral incisor is missing at the site of the cleft.

After treatment, the lip has been repaired, the cleft is no longer visible in the dental arch, and the canine has taken the place of the missing incisor and been reshaped to resemble such a tooth, to establish a harmonious smile.

Sébastien F: Before treatment



CHAPTER VI: FUNCTIONAL DEFORMITIES

As their name indicates, these deformations are the result of one or more parts of the mouth malfunctioning, with the tongue once again playing a decisive role.

- A: Retained and Ankylosed Teeth

In the case of retained teeth, the cause is functional: abnormal spread of the tongue in the mouth prevents the teeth from erupting.

In the case of ankylosed teeth, the cause is accidental: the teeth are welded to the bone following a blow or reimplantation and cannot be moved.

Retained teeth develop but do not appear in the mouth. The tongue, which is always obstructing the place where they should be growing, prevents them from erupting. Consequently, the roots of retained teeth develop by penetrating into the bone of the jaws, and in extreme cases, such roots of upper teeth may reach the sinuses or those of lower teeth, the lower side of the mandible.

There are many disagreeable effects, including in particular, sinusitis following a dental infection and the risk of fracture of the mandible.

Fabien T: Before treatment: retained tooth

Fabien T: After treatment



Appropriate treatment allowed Fabien T's retained teeth to develop normally. The results obtained were stabilized by functional retraining to correct the position of the tongue in the mouth, which consequently corrected the occlusion.

- B: Open Bite

When the tongue is interposed between the two dental arches, whether at rest or when functioning, it causes open bite, or space, between the upper and lower teeth, which is visible when the jaws are clenched. The tongue may be interposed at the sides, between the premolars and molars, or be spread over the entire surface of the arches. Deformities can result, which vary depending on the areas of the mouth affected and the degree of pressure exerted by the tongue on various parts of the dental arches.

The Three Main Types of Open Bite

- 1: Unilateral Open Bite

The tongue is only interposed on one side of the mouth, producing asymmetry of the face.

In the case of Stéphane R., thumb sucking, not the tongue, is responsible for the open bite. Because of this, the canine lacks space and the incisors are deformed.

Christelle L

Here, the tongue interposed on one side of the mouth is preventing the lower teeth from developing on the mandible, which is the reason for the space observed. The face has become asymmetrical, with the chin deviating to the left. To compensate for this, the patient moves her jaw to the side to increase her area of mastication, which is decidedly inadequate. The repercussions on the joint are significant (see below).



- 2: Bilateral Open Bite

The tongue, interposed on both sides between the teeth, creates gaps on either side of the axis of the mouth.

In this case, occlusion occurs on the last molars and the incisors, that is to say, only the last molars and the incisors of the upper and lower teeth make contact. The premolars, occasionally the first molars, and from time to time the canines are infraoccluded: these teeth, having been unable to complete their vertical growth, have not completely erupted and their crowns remain short in height.

Patricia G: Before treatment

Patricia G: Before treatment

When the teeth are clenched, the upper incisors cover the lower ones to too great an extent and only the molars make contact. Interposition of the tongue is retarding the development of the premolars.

Patricia G: After treatment



Patricia G: After treatment

- 3: Total Open Bite

The tongue is spread completely between the dental arches, with only the last two molars making contact. In this case, the child swallows without chewing and is unable to articulate words.

Karine F: Before treatment After treatment

In little Karine F., the teeth are not making contact with each other at all, and are thus finding it difficult to develop. The interposition of her tongue between her teeth each time she swallows is slowing the development of her permanent teeth.

Marie Hélène G: Before treatment After treatment



Here we have an adult. When the teeth are clenched, only the last molars are in contact. The

upper canines are prominent. Since chewing is impossible, the patient simply swallows. This

open bite is due to complete interposition of the tongue

Consequences of Open Bites

In all cases of open bite, interposition of the tongue interrupts growth of the alveolar bone (which directly surrounds the teeth in the alveoli). As a result, not only does this bone fail to grow, but growth of the teeth is likewise impeded.

Before treatment

After treatment



The thumb and the tongue have been interposed between the two jaws, preventing bone, alveolar and

dental growth. A device providing a barrier against the tongue allowed growth to resume normally

and correct occlusion to be achieved.

In unilateral open bite, the face becomes asymmetrical because the individual is obliged to move his lower jaw out of line to make maximum contact with the teeth of the upper jaw and facilitate chewing, in which he uses essentially horizontal movements resembling those of ruminants. On studying the face it can be seen that the chin is no longer aligned with the nose, while both dental arches have shifted laterally to an equivalent extent. On one side, the upper molars are to the inside of the lower molars (maxillary dental arch contraction) while on the other side, the upper molars are to the outside of the lower molars (maxillary dental arch expansion). As a result, the individual has a crooked mouth without being aware of it.

Before treatment

The roots of the canines are developing towards the lower edge of the mandible

After treatment

The tongue works asymmetrically either for inherited reasons or because of prolonged sucking on a finger at the side of the mouth. Treatment consists of preventing the tongue from spreading to one side and restoring the ability of its muscles to work symmetrically, to avoid temporomandibular joint problems.

However, this is not only a problem of aesthetics. It often leads to two others, particularly in adulthood, namely dysfunctioning of the jaw joints (the temporomandibular joints) and grinding the teeth while asleep, also known as bruxism.



- 1: Jaw Joint Dysfunction

Poor functioning of the mouth can lead to wear of the temporomandibular joints (TMJ) resulting in clicking sounds, pain and, in extreme cases, the jaw becoming locked, making it impossible to eat. In cases of unilateral open bite, the upper jaw does in fact shift to fill the gap when chewing is required. The individual involuntarily compensates for the gap by moving the lower jaw sideways to increase the surface available for chewing. The joint on the open bite side is depressed inwards, and conversely the opposite joint is stretched. After several years, joint pain, clicking, locking and neuralgia occur. These problems can be treated by reducing the open bite by preventing the tongue from being interposed between the teeth on the side affected. An appliance known as an activator is used to do this. It is generally worn at night and keeps the teeth closed and correctly aligned one above the other. On the open bite side, since the teeth are no longer being hampered by the presence of the tongue, they gradually grow as they should and erupt completely. With regular readjustment of the appliance as these teeth grow, the open bite gap responsible for all the problems will be filled. A painful surgical procedure can thus be avoided, and the relief provided by this appliance is almost immediate.

The corrective effect of the activator must be reinforced by retraining for a period of six months to a year. This will consist of daily exercises, for a quarter hour with the appliance and a quarter hour without it, to strengthen the muscles of the tongue symmetrically and thus reestablish normal function during swallowing and chewing, without the tongue being interposed between the teeth.

A check is also needed to see that the tongue is not interposed between the teeth when articulating words. This requires performing exercises in articulating sounds with the lips, only moving the tongue to pronounce dental sounds.

If it is necessary to align the teeth, the activator treatment + retraining can be supplemented by fitting bands and other appliances, depending on the size of the open bite to be reduced.

Treatment ends when the upper and lower teeth come naturally into contact, having been recentered and symmetrically aligned on each side of the axis formed by the two midlines of the jaws. The teeth on the open bite side must also have fully emerged to come into contact with their antagonists. The open bite will have disappeared, the jaws will be recentered, and the patient will be using his tongue correctly to swallow saliva and food, and to speak. His pain and locking of the jaw will be no more than bad memories. The results should nevertheless be made to last by fitting a retention appliance (see the lexicon).

- 2: Tooth Grinding or Bruxism

Bruxism is grinding the teeth during sleep. It leads to premature wear on the teeth, with the enamel becoming progressively thinner.

It seems that insufficient stimulation of the soft tissues (periodontal tissues) during the day causes accumulation and congestion of blood. The resulting discomfort leads to the individual grinding his or her teeth while sleeping, to compensate for insufficient daytime stimulation.

The orthodontist will check that no obstacle is present (no tooth or extra point on a molar, called a cusp) that would prevent lateral movement or cause the teeth to shift combined with wear to the joints of the jaw. A slight open bite with midlines out of alignment may also provoke a shift and grinding

of the teeth. Treatment consists of reestablishing normal occlusion, followed by exercises in which the teeth are clenched, to encourage normal blood circulation during the day.

With a bilateral open bite, two main problems arise simultaneously:

- The first occurs in the open bite itself: the teeth are not able to grow completely on the sides of the jaw affected, resulting in lateral (meaning, on the side) infraocclusion.



- The second concerns the upper or lower incisors: when the teeth are clenched, the only contact between the molars is of those at the back, forcing the upper incisors to overlap those of the lower jaw. This is known as supraocclusion and in this case is anterior because it affects the front teeth.

Before treatment

Result obtained at the end of treatment

The tongue had to be prevented from entering the spaces so that the teeth (canines and

premolars) could develop. Banding proved effective.



As the above examples show, the treatment, which is essentially functional, consists of preventing the tongue from impeding normal growth of the bones and teeth. Functional retraining of the tongue is essential for optimizing the corrections achieved by fitting banding appliances or carrying out other orthodontic treatment.

- C: Supraocclusion

As we have just seen, the upper incisors may excessively cover the lower ones, producing what is known as supraocclusion. They are visibly projected forwards until they meet the lower lip, which hinders their growth.

Marie Ange F: Before treatment

The growth of the upper incisors has been obstructed by the lower lip, resulting in incisor

supraocclusion. The incisors are visible even with the mouth closed.

Marie Ange F: After treatment



Treatment consisted of moving the upper and lower incisors backwards by freeing the space needed

via 4 extractions, reducing advancement of the maxilla, and causing the incisors to retract into their

alveoli so that the relationship established between the jaws and the teeth would be correct.

Since the lower incisors are covered by the upper ones, they touch against the palate, which slows alveolar growth. The lower jaw finds it difficult to develop, while development of the upper jaw is exaggerated.

The upper incisors protrude, growing until they meet the lower lip. The lower incisors are

obstructed by both the palate and the lower lip.

Before treatment

After treatment



Supraocclusion may also be caused by the teeth at the side lacking height. When the teeth are clenched, the upper incisors cover the lower ones to too great an extent.

Before treatment

Results obtained after treatment

Before treatment



- D: Diastema or a Gap Between the Teeth

Poor tongue posture inside the mouth is often responsible for the formation of a space between the teeth called a diastema. During swallowing, the tongue is placed between the teeth, preventing them from closing up together.

In the case of Carine G., below, there was also a problem of thumb-sucking, which explained the size of the gap between the incisors.

With banding and the essential retraining of the tongue, the teeth have been correctly repositioned, producing a much more harmonious profile.

Before treatment

After treatment



- E: Neuralgia or Toothache

Neuralgia is pain, sometimes intolerable, which occurs in healthy teeth despite the dentist being unable to find any evidence of caries. The pain persists even when the teeth in question have been devitalized or removed.

At present, there is no clear explanation for this phenomenon. Perhaps the pain is caused by a lack of stimulation of the teeth. Perhaps the cervical spinal cord is responsible, since all nerves pass through this area on their way to the brain.

The role of the orthodontist will be to correct any malpositioned teeth and provide exercises to stimulate the periodontal tissues and blood circulation around the teeth. Four months of such exercises and fitting an activator are generally enough to make the pain disappear once the teeth start to articulate normally.

- F: Receding Gums or Periodontal Disease

Older adults are not the only ones to have this problem. Young adults, from 25-30 years old, are also affected. The first signs are gum retraction and bleeding and the accumulation of tartar around the base of the teeth. This is due to the habit of infantile swallowing still persisting. The saliva collects behind the lower incisors and the mineral salts and food debris contained in it are deposited there. As a result of the insidious interplay of forces exerted by the tongue and lips in this type of swallowing, the alveolar bone of the incisors (into which the teeth are directly fixed) is dissolved away. As it gradually does so, the pocket formed fills with the tartar deposit carried there by the saliva, which itself stagnates behind the incisors before being sucked up by the tongue and lips.

Sheltered from the saliva, which is antibacterial, it is not difficult for the bacterial flora to develop in the deposits of tartar that have accumulated in the pockets around the teeth. The gums gradually retreat, a sign of resorption of the underlying bone. This explains why gum grafts applied to teeth without using bone fail to last for more than six months.

Just as a nail knocked crookedly into wood is continually subject to transverse forces, the teeth, with demands made on them from right and left and from front and back, enlarge the holes (the alveoli) in which they are fixed. As its alveolus enlarges, the tooth loses its seating in the bone, which is resorbed around the root of the tooth. The saliva, with its load of food debris and microorganisms, penetrates the pockets around the root, causing suppuration. The teeth are finally expelled (fall out), and the bone and gum is completely resorbed.

Example of periodontal disease



On the other hand, when a nail is driven straight into a plank with perpendicular blows, each blow secures the nail further in the plank. In the case of a tooth, it must be stable in the bone and receive vertical forces to be consolidated. Orthodontic treatment will therefore be essential, once the infection has been successfully treated and the dental hygiene problems are being correctly managed by the patient (interdental brush, gum stimulator tips, dental floss, etc.). Loosening is essentially due to the teeth not being sufficiently stable on the bone base supporting them: they tilt either forwards or backwards on one or both jaws at once. As they are inclined, rather than straight, they are fragile, which explains the mechanism of their loosening.

What then is the role of the orthodontist? He will set the teeth vertically on the bone using appropriate treatment. The destroyed alveolar bone will be able to reconstruct itself through the action of the consolidation forces exerted on the now correctly repositioned teeth, which will stimulate this periodontal reconstitution.

Reconstitution of periodontal tissues by orthodontic treatment alone

On the first X-ray it can be seen that, at the beginning of treatment (March 1999), the tooth was not

surrounded by bone; one month later, the bone (gray part around the root of the tooth) had already

reached the root; by January 2000, the bone had completely surrounded the tooth, which would

serve as a pillar for a bridge to replace the missing teeth.



Once again, functional retraining will play a decisive role. Frequent exercises, consisting in particular of clenching the molar teeth tightly, followed by swallowing, will stimulate regrowth of the bone and gum. The dental arches must be in complete contact over their entire length, while the teeth must be straight, with the incisors becoming naturally stronger. A pad is created around the gum and the bone and gum gradually progress up the tooth.

It is important to maintain impeccable dental hygiene in parallel with treatment to avoid residual infection. The deposition of tartar will be found to decrease as correct swallowing is reestablished. When this is achieved saliva will no longer collect behind the incisors but will be drawn up by the tongue, so that it will no longer be able to stagnate. The pockets around the teeth will be resorbed.

Once gum recession has been successfully resolved, it is recommended to wear a night appliance (an activator) for about a year to reinforce the functional retraining, and to perform teeth clenching exercises at least ten times per day, contracting the masseters three times before swallowing. Chewing gum correctly can help strengthen the teeth.



CHAPTER VII: CURING BY FUNCTIONAL RETRAINING

The treatments mentioned in the previous chapters focus on children, individuals still in the growth stage, but this does not mean that treatment is not possible after growth has been completed. Even if growth per se no longer occurs in the adult, bone is constantly being renewed and hence there is the possibility of remodeling and correcting it. Orthodontic techniques associated with retraining avoid resorting to often major surgery, which may even be less effective than orthodontics if the causes of the problems are not treated in depth.

Orthodontic treatment is based on the idea of equilibrium within the mouth. The teeth are positioned where the various muscle forces exerted on them cancel one another out. This "point of equilibrium" determines the position of the tooth, and may be correct, or not.

The fact that the tongue is the "orchestra conductor" of the mouth means that special attention must be paid to its position at rest and to the movements it makes when the various functions of the mouth are performed, such as swallowing saliva, drinking, eating, talking, etc. We must ensure that the tongue "moves" properly and that people develop a "mature" type of swallowing, as practiced naturally in most adults and the only type worth performing if preserving the teeth is a priority.

We have seen earlier that the orthodontist can literally rebuild the dental arch so that the teeth are properly aligned without spaces between them. He will bear in mind the space available on the jaws, the number of teeth and tooth buds present, the presence of devitalized or endangered teeth, supernumerary buds, missing teeth, etc. Based on these aspects and many others, he will choose the teeth to keep, those to extract and those to be corrected, and will always consider the quality of the intercuspation of the upper and lower teeth, the shape of the face and, of course, the age of the individual regarding whether growth is complete. He will always pursue his strategy with an eye to the future, and his treatment will take into account any future changes in his patient's dentition. Each case will be individually assessed to identify the best possible solutions.

The fact remains, however, that irrespective of specific individual aspects, the orthodontist's treatment will be based on three principles mentioned earlier in this book, namely:

• 1: Functioning (correct or incorrect) of the components of the mouth, which determines its shape and, consequently, most of the situations of disharmony treated by orthodontics

• 2: The soft tissues, which exert muscle forces that control the position and possible remodeling of the bones and teeth— not the reverse.

• 3: Mature swallowing, a prerequisite for any correction. Correct functioning of the mouth implies that it will have been acquired.

To assist treatment there are corrective devices, which will be described later, and also a series of exercises aimed at retraining the functioning that has given rise to the malformations seen. Retraining also aims to stabilize and maintain the corrections achieved with the appliances, since there is no point to straightening the teeth (orthodontics) if the bad habits that are the source of the problems are not corrected. The problems will inevitably resurface, otherwise, and will be more difficult to resolve.

It should be remembered that adults as well as children may undergo orthodontic treatment.

- A: Restoring Correct Function

Any retraining can be accomplished without using an appliance if patients are sufficiently motivated. Fitting a device is not essential for achieving results; it is simply an aid to retraining.

It is difficult, however, to eliminate undesirable reflexes imprinted in our brains and replace them with new ones that are more consistent with correct functioning of the parts of the mouth. In addition, at night the subconscious takes over, especially when the phenomenon is hereditary, which is frequently the case. Yet cases of mandibular prognathism (protruding chin) have been treated without any relapse solely by retraining.



Good tongue posture can be achieved by swallowing exercises and also by exercises focused on articulating sounds and chewing, which allow patients to construct new reflexes that this time are correct. Whether talking, singing, swallowing, chewing or sometimes even breathing, tongue dysfunction equally involves both the tongue and the position of the teeth. Retraining the act of swallowing is therefore beneficial not only for swallowing per se but also for articulating speech.

Establishing Mature Swallowing

The normal swallowing process can be described as follows:

- 1: At first, the tongue is supple and fills the entire lower dental arch, without covering the teeth, while the lips are soft and parted.

- 2: Then the subject brings his teeth together (the molars in particular need to be in contact), while the tongue is flattened against the rim of the palate and the saliva drawn into the space formed in the middle.

With this in mind it is possible to create a few simple swallowing exercises:

- 1: The first is clicking the tongue in the middle of the palate, producing a clear sound (as if imitating a trotting horse) for one to two hours on the first day and half an hour on subsequent days. This exercise helps develop certain muscles of the mouth that were not working adequately before.

- 2: Another exercise consists of strongly clenching the molar teeth, keeping the lips relaxed; this exercises the muscles that are the point of support that initiates swallowing.

- 3: The next exercise combines the first two. For half an hour each day, the recommended procedure is to click the tongue ten times in succession, then clench the molars and swallow the saliva once. If swallowing does not occur, an alternative is to click the tongue ten times, then clench and release the molars on each side, and finally swallow, with the lips always soft, relaxed and parted; the cheeks should never be contracted.

For these exercises aimed at developing mature swallowing to be effective, it is important for the individual to be relaxed so that the tongue can relax as well. It should perform particular movements at particular times, but apart from these times should be at rest and relaxed. The purpose of these exercises is to reduce the volume of the tongue and ensure that the movements it makes are more precise and more limited, since the types of dysfunction seen are often the result of accidental spreading and uncontrolled use of the tongue.

With this retraining, the tongue becomes a flexible membrane able to draw up the saliva which is produced continuously and accumulates in the mouth. These exercises also help develop the muscles in the neck that connect the tongue to the skeleton, as well as those that close the mouth.

Finally, to help young children abandon the suction swallowing characteristic of infants, when the child begins to eat from a spoon at approximately six months of age we can push the spoon well into the mouth to prevent the child from sucking up the food, and force the tongue to work towards the back of the mouth rather than towards the front, as would be the case when sucking.



Restoring Correct Articulation of Sounds

Simultaneous correct use of the tongue, jaw and larynx is essential for voice production.

Because the tongue is the most important moving organ, good control of its anterior part allows the dental sounds [t] [d] [n] to be articulated correctly, the tip of the tongue being applied to the palate.

On the other hand, the tongue remains still and low during the articulation of voiceless consonants, [p], [k], [f], [s], which are produced by the lips with the soft palate (the rear, mobile, flexible part of the palate) raised.

The voiced consonants [b], [g], [v], [z] are produced by the larynx, with the soft palate raised; the tongue does not move.

The nasal consonants [m] [n] are produced by the nose, with the soft palate lowered.

For oral vowels, the lower jaw is dropped and the tongue remains low and still, whereas for the nasal vowels, the lips are slightly parted and the sound passes through the nose.

Exercises

These are different depending on whether they focus on the articulation of dental sounds ([t], [d], [n]) sibilants ([s], [z]) or fricatives ([sh]).

For the dental sounds, the tongue remains low, flat and relaxed behind the incisors; the tip of

the tongue is applied against the mucosa of the palate behind the incisors. The exercise consists of pronouncing syllables containing a dental consonant, completing the sounds with the various vowels [a], [e] [i] [o] [u], [ou], while keeping the teeth closed together (to force the tongue to work inside the mouth).

Lists of words from the dictionary made up of these phonemes can also be read aloud.

The subject needs to be aware of the position of his or her tongue, which must be behind the incisors and just touching them (with the tip pressed against the palate), not interposed between the teeth. The teeth must be closed firmly together while pronouncing the syllables [ta], [te], [ti], [to], [tu], [da] [de], [di], [do] [du] and [na], [ne], [ni] [no], [nu].

The subject should stand in front of a mirror to check that the tongue does not extend beyond the teeth. Movement of the tongue must be gentle and limited. If difficulties occur, [l] can be used as a reference (because it is naturally pronounced by raising the tongue).

For the sibilants, the tongue must be flat, supple, relaxed and still.

The subject should smile broadly and let the air pass, whistling over the tongue, which should not be raised or interposed between the teeth.

For the fricatives (e.g., the [sh] in "shirt") the tongue should not come between the teeth at the sides: the lips are pushed forward, the teeth closed together and the tongue low, with the sounds being articulated by the lips.



Establishing Correct Chewing

Chewing food is a voluntary action initiated by closing the teeth together particularly tightly. (As we have already said, the masseter muscles are the most powerful muscles in the body.) During chewing, food is crushed between the molars. When it has been ground up sufficiently, the molars need to be strongly clenched to allow swallowing. The lips should stay relaxed during the swallowing process; they are not required for sucking.

Essential advice: make sure that you chew on both sides!

The enormous force exerted when swallowing, which can be as high as 80 kg/cm2, stimulates the alveolar bone and, more broadly, the periodontal tissues (the tissues surrounding the tooth and holding it in the bone). This helps reduce periodontal disease, improving blood circulation problems around the tooth and strengthening the ligaments that attach it to the bone.

At the end of basic treatment, which will not exceed one year, an X-ray assessment is made to evaluate the effect on the growth, or the position of the lower incisors, or the reduction in the difference between the bones of the two jaws.

As the following diagram shows, the results can be seen by superimposing the profiles from before and after treatment.



-

Superimposed profiles, beginning (in black) and end of treatment (in red).



B: Gaining a Beautiful Smile

By Correct Positioning of the Teeth on the Bone

Let us briefly recall that a tooth correctly placed on its bony base is a basic component of a beautiful smile. It must be positioned straight and perpendicular to the bone. Indeed, the term orthodontics means "the science of straight teeth."

However, aesthetics is not the only consideration. As we have seen in previous chapters, having perfectly straight teeth or having them corrected by orthodontic treatment is a sign of good dental health and good health in general, since the vital functions performed by the mouth and teeth have a significant impact on the overall metabolism of the whole body. Teeth correctly placed on their bony base correctly carry out their functions.

By Correct Intercuspation and Good Alignment of the Teeth

Satisfactory intercuspation of the molars results in good occlusion, i.e., the teeth fit together properly. If, after basic treatment, intercuspation is satisfactory, there is no need for banding treatment (also known as treatment with a multiple attachment device). On the other hand, if adequate improvement has not been achieved after several months of treatment (usually 6 months), there must be a change of method for functioning to continue to be retrained.

Correct functioning is essential if the results of treatment are to last. If the permanent teeth are all present in the arch, banding treatment can be started. Otherwise it must wait until they have developed. In principle, the aim of banding is to improve tooth alignment and intercuspation mechanically, providing first that the reflexes are correct. If the reflexes have remained infantile, this banding approach, which, as has been said, is purely mechanical, has drawbacks, such as the length of time it is needed, possible pain and lack of stability.

The solution of just stabilizing the teeth by fitting a palatal (top) and lingual (bottom) wire for several years is not satisfactory. When the adhesive gives way after a few years, the teeth will resume their former incorrect position because functioning has not been corrected and the proper muscle reflexes are lacking. The teeth will move back into the neutral zone where the forces exerted on them cancel each other out. This is why it is extremely important to correct functioning so that the area where the forces cancel each other out coincides with the correct position of the teeth. Recurrence of the problem will then be avoided.

In fact, banding needs to be used to align the teeth and bring about intercuspation while at the same time retraining functioning through exercises, if this has not been done before, and the use of alert devices; intercuspation will then occur almost spontaneously.

Once functioning has returned to normal, i.e., when the tongue or lips are no longer interposed, all the problems are solved: The teeth are simply waiting to return to their correct position.

The spaces left by extracted teeth close up easily (because the tongue is not in the way), while the teeth straighten on the bone.

Chewing becomes efficient.

All periodontal tissue is consolidated: alveolar bone grows back around the teeth as do the gums, without the need for grafting.

Pockets of pus fill in after disinfection.

Pain disappears.



With proper functioning, it becomes easy to eat and swallow meat because chewing is effective again. I have often found that children or adults "who do not like meat," in fact have poor oral function. After nibbling at the meat, they try to suck the juice out. As a result all that is left in the mouth is a ball of fibers resembling straw, which is impossible to swallow. When meat is chewed, torn up by the canines and crushed by the molars, a bolus is obtained which is easy to swallow.

Banding treatment involves attaching bands or brackets onto the teeth, with arches (shape memory metal wires with the desired correction curvature), of an appropriate diameter and shape to produce the desired effect, threaded into the bands. The shape of the arch produces repositioning of the teeth, and their roots, within the bone. Elastic or metal ligatures firmly fix the arch to the band.

Fitting bands and brackets onto the teeth is meticulous and accurate work, but is widely known.

The efficacy of alert devices no longer needs to be demonstrated, even in adults and especially at night when old reflexes reappear, and fitting them in place presents no major difficulties. When making a tooth change its position is difficult because of an obstacle, such as the tongue, lips or cheeks, and exercises are not sufficient to alter the situation, we insert spikes which are painful when a movement is faulty, but painless when functioning is normal. Fear of being hurt or pricked modifies behavior. At the same time, the spikes make the individual aware that functioning, without which correction is impossible, is not occurring correctly.

- C: Stabilizing the Results

Through Appropriate Exercises

Results will be obtained even faster if exercises are done regularly and functioning has returned to normal. It is therefore essential to perform the exercises during banding treatment so as to imprint the reflexes effectively in the brain. Reflexes are indeed acquired by repetition, which makes it possible to create new reflexes to combat heredity or many years of incorrect functioning of parts of the mouth. It is true that this is neither easy nor evident, but with perseverance, determination, awareness of incorrect movements of the tongue and also the use of alert devices indicating lack of compliance with correct behavior, correct reflexes can be instilled.

When functioning has returned to normal, the treatment is not painful and the teeth are no longer sensitive. They move easily into place, as they no longer encounter obstacles to their movement. On the contrary, they are helped into position by the pressure exerted by the various muscle forces and take their place naturally in the neutral area where the opposing forces cancel each other out. Treatment is quick, painless and stable, and this stability is ensured as long as functioning is properly maintained and the muscle reflexes coincide with the position of the dental arches.

On the other hand, if there is difficulty in establishing correct functioning, alerts, such as spikes or barriers, need to be used to prevent certain abnormal movements of the tongue, lips or cheeks. These alerts are placed on the bands to make undesirable movements painful. Banding, in addition to its contribution to correctly positioning the teeth, is thus an effective aid to neuromuscular and functional retraining.



By Fitting a Tooth Positioner

If banding has yielded results easily within a year, the appliance can be removed and a tooth positioner fitted. This is a removable transparent device which takes on a whitish hue when worn (so that the orthodontist can verify whether it is being used). The purpose of this device is to stabilize the teeth and reflexes and perfect the alignment of the teeth by correcting any small defects remaining. It should be worn for a year while doing daily exercises. During the first few days, the device must be worn night and day, exercising as much as possible. After checking that nothing has changed, it should be worn for five hours a day as well as at night. The number of hours per day is then reduced by half an hour each month.

If, on the other hand, results have been difficult to obtain because of the hereditary nature of significant dysfunctioning, retention can be applied using an activator to maintain correct occlusion and reinforce a good chewing reflex. This appliance should be worn for a year or more with daily exercises. When retention ends, the reflexes must be maintained by performing correct swallowing each morning (e.g., when brushing the teeth).

As these devices are not always easy or comfortable to wear during the day, the teeth can be fitted with small, invisible appliances or transparent guards; these are practical and easy to wear but are not effective in stabilizing reflexes. The tooth positioner must therefore continue to be worn in the evening and at night and appropriate exercises performed.

Midway through retention, an X-ray examination should be performed to check not only the stability of the effects obtained and the ability of the wisdom teeth to grow normally, but also whether the procedures have been carried out correctly and are not causing a problem.

During this examination, the following aspects are checked for improvement:

The position of the upper and lower incisors The amount of displacement of the bony bases achieved The changes in direction of growth of the teeth that have been induced

All of these improvements can be seen if the profiles from before, during and after treatment are superimposed on one another.

Banding treatment is complete when occlusion has become normal, i.e., when it meets the following criteria:

The molars and canines intercuspate normally.

The incisors are correctly positioned on their bony bases: the upper incisors should be slightly in front of the lower incisors (they work like a pair of scissors).

There should no longer be gaps (diastema) between the teeth as far as the premolars and, if there is still any gap between the molars, it should be filled by the growth of the second molars and later, the wisdom teeth (except where the shape is abnormal).



- D: The Use of Corrective Appliances

The mouth must be prepared no later than eight days before the start of treatment. Germectomy (extraction of tooth buds) of the premolars is performed at between 8 and 10 years of age, and of the wisdom teeth at 14 years old and older.

To counter bone deformities during the period of growth, appliances will be fitted such as the Activator, the Crib, the Quad Helix or the Delaire Mask. These devices, which will be described below, act on growth by either slowing or stimulating it.

The Activator

Activator

In cases of maxillary prognathism (the maxilla and upper teeth projecting in front of the lower jaw), an activator is used during the growth period to slow the growth of the maxilla and increase that of the mandible (lower jaw).

The activator is a simple device that consists of a palatal plate with an arch, which passes over the upper incisors, and a mandibular plate joined to the maxillary plate in hyperpropulsion (i.e., propelled forwards), bringing the incisors edge to edge. The device works using muscle force alone, which tends to pull the maxilla backwards. It is a removable appliance and can be worn at night and for at least three hours during the day, for a period of 6 to 12 months. It not only affects the growth centers but also stretches the ligaments in the joints. This effect is offset and neutralized by daily exercises maintaining the elasticity of the ligaments. The growth obtained in the mandible reduces the space between the maxillary and mandibular bases, thus providing more room for development of all the teeth, including the wisdom teeth.

The activator also channels tongue movements for both swallowing and articulating words. Exercises are necessary on altering reflexes in order to learn how to swallow correctly. Initially the patient drools and sucks noisily, thus demonstrating his or her impairment. Very soon the behavior changes and the individual will know how to swallow and articulate sounds, applying the tongue correctly.



Words are articulated by keeping the tongue low, relaxed and still; only the lips move and articulate the sounds, except in the case of the dental consonants ([t] [d] [n], and [l]).

The entire upper arch retracts and the upper molars are able to intercuspate well with the lower molars, an effect which is remarkable because it is otherwise difficult to obtain. Wearing a device that protrudes from the mouth is avoided. It is easier with the activator than with other means to retrain swallowing and speech, and the appliance also ensures that the teeth are aligned. Wearing it regularly, combined with the exercises prescribed (see elsewhere), yields tangible results in two to three months.

The activator can also correct double protrusion of the incisors (where both the upper and lower incisors protrude and tilt forward excessively on the basal bone because they are pushed forward by the tongue). The activator combined with exercises helps make the lower incisors perpendicular again by promoting growth of the mandible. Extraction of the premolars is thus avoided. Moreover, the lower incisors, now squarely placed on the bony base, act as a reference for the profile.

The role of retraining is very important, optimizing the purpose of the appliance and stabilizing the results obtained.

Sketch of mandibular growth



Activator

The activator is fitted by adjusting the upper part to the palate, then moving the lower jaw forward until the lower incisors fit into the impressions of the teeth on the lower part of the appliance.

The swallowing exercises associated with wearing the activator consist of placing the incisors in the spaces reserved for them on the activator, swallowing while firmly closing the jaws and ensuring that the jaw muscles, particularly the masseters, contract strongly, leaving the lips relaxed, soft and slightly apart. This movement must be repeated several times until swallowing is triggered naturally, which can be observed by movement of the Adam's apple. If it is performed incorrectly, the patient drools and/or sucks in his or her saliva noisily. This exercise should be repeated for 5 minutes at least 3 times until it becomes easy, and begins to be imprinted on the brain. Furthermore, it prevents the joint ligaments from stretching, while maintaining their elasticity.

The patient should also practice articulating words properly. With his or her teeth clenching the appliance, he or she should practice speaking while keeping the tongue still; the tongue must be supple and relaxed and only move when pronouncing dental sounds ([d], [t], [n] ), which are the most difficult sounds to produce (the tip of the tongue must be raised against the palate). If there is any difficulty, the sounds can be practiced by pronouncing them with the consonant [l].

Other sounds are produced with the lips, without significantly moving the tongue. Articulation should be achieved by moving the lips, not the tongue, which should remain relaxed, still and low in the oral cavity.

These exercises are extremely important for preventing the patient from drooling, sucking noisily or speaking by opening his mouth to an exaggerated degree.

The Crib

The crib is used for open bite, i.e., when there is a vertical gap between the upper and lower teeth (the upper and lower teeth do not make contact everywhere).

Because the most frequent cause of open bite is interposition of the tongue, the aim of the appliance is to prevent the tongue from leaving its normal position by virtually enclosing it within the mouth, i.e., containing it within the dental arches. It is therefore a sort of temporary "cage" for the tongue so that it loses its poor functioning habits and remains within the dental arches. The open bite may be anterior, unilateral, bilateral, or total.

The crib allows growth of the alveolar bone, which accompanies eruption of the tooth.



Crib

The crib, which is made by a dental technician, is a palatal arch (fitted against the palate) welded onto two bands attached to the first two opposite molars in the upper jaw (see photo). It can go from canine to canine or molar to molar depending on the size of the open bite and the result desired.

The crib cannot be removed during treatment, which lasts for about three months, since complete eruption of the teeth occurs relatively quickly. For one or two days it causes discomfort that can be reduced by teaching the child to clench his or her teeth several times to swallow the saliva, the molars being kept tightly closed together. He or she must also learn to speak behind the crib and not beneath it, as this would cause it to sink into the palate, causing injury.

The Quad Helix

The Quad Helix is used to correct a palate which is too narrow, where the upper molars articulate within the span of the lower molars (maxillary contraction) and not just to the outside of it, as should normally be the case.

The Quad Helix

The Quad Helix is composed of four springs attached to two bands around the first upper molars and two lateral branches which act on the premolars. It helps widen the palate until half the surface of the upper molars is articulating to the outside of the lower molars. It also encourages wearers to move their tongue less due to the discomfort caused.

The appliance is adjusted each month to increase the width of the palate and set the lateral branches along the premolars so that they do not interfere with the tongue. The spring must follow the shape of the palate and be close enough to it to prevent the tongue from being inserted between the spring and the palate, otherwise the appliance could be detached on one side, resulting in the child being prevented from closing his or her mouth.



The Quad Helix is an improvement on the jackscrews which were previously used and which had to be adjusted each week by a quarter turn and worn for 1 to 2 years. With the Quad Helix, the result is obtained in three months, but it is better to consolidate it by continuing to wear the appliance for three additional months.

Exercises to be undertaken consist of clenching the molars ten times a day in order to straighten the roots.

The Delaire Mask

The Delaire mask is used when there is mandibular prognathism (the lower jaw protrudes in front of the upper jaw).

Delaire Mask

The object of this appliance is to encourage the upper jaw to grow forward while slowing the growth of the mandible.

It is an external appliance which is supported on the chin and forehead, connected by elastic bands to a welded vestibular bar attached by bands to the last upper molars. It is usually worn at night or for part of the day in extreme cases, until the incisors of both jaws are correctly positioned relative to each other.

This result can also be achieved with a Para-Andresen appliance, which presses on the lower incisors and causes the upper jaw to develop (see photo below).



Tangible results can be obtained in 6 months to 1 year as long as certain exercises are performed:

The patient must exercise every day by swallowing without thrusting his/her tongue onto the mandible; he/she should draw back his/her tongue slightly to swallow, with the molars firmly together;

He or she must practice speaking every day, keeping the tongue low, except when raising the tip to the palate for the dental sounds, [d], [t], [n], and as relaxed as possible for other consonants.

If the mandibular prognathism is not too pronounced, using a para-activator can slow the growth of the lower jaw and activate growth of the upper jaw, while retraining the tongue.

Para-Andresen appliance



CONCLUSION

Theory Proven by the Results

The analyses in this work would be pure speculation and imagination, at best considered appealing or original, if they were not the fruit of long observation of both young and older patients, and particularly if they had not been tested in practice. Patients expect orthodontists to provide concrete results, not extravagant theories.

The simple principles that have been identified to help us understand the proper functioning of the mouth, a very complex cavity, should assist in establishing accurate diagnoses and, consequently, help in deciding how to acquire or restore its normal functioning.

The fundamental property of the theories that can be construed in this regard is that the proof is visible and indisputable, whether positive or negative: the changes obtained by the treatments prescribed can be objectively recorded by taking photographs and X-rays before and after treatment. There is no question here of subjective impressions. To validate the effectiveness of treatment, patients are not asked "if they feel better" or "if they think they have been cured." The condition of the oral cavity at two different points in time is compared visually.

As we have seen, the mouth is a tool used for several purposes. Like any tool, it needs to be used in a particular way if the owner wishes to avoid damaging it prematurely. It is, however, a tool that does not come fully assembled at birth: the owner must steadily construct it over time from his or her parents' genes.

Two main scenarios may arise:

1. Nature (i.e., heredity) may fail to transmit to the individual all the elements required for the formation of healthy teeth. This is the case, for example, where tooth buds are abnormally absent (see the section on Agenesis).

2. The components provided by nature—and which appear progressively—are correct in number, but the individual has caused them to be poorly positioned in relation to each other through bad habits in childhood that have tended to persist into adulthood.

The work of the orthodontist is to restore the tool to its proper condition and above all to teach his patients to use it correctly, giving them appropriate instructions for its use, to ensure that it remains in good condition. The orthodontist must therefore correct nature when it is at fault (e.g., agenesis, cleft palate or diastema) or correctly reassemble the various parts of the tool when its deformation (e.g., all cases of open bite) and consequently early destruction (tooth loss or wear) has been caused by incorrect use. In every case, he must teach the individual to use this tool properly, hence the extreme importance of retraining.

The Case of Caroline O.

Before concluding, I would just like to convince you of the efficacy of orthodontic techniques when they are combined with conscientious functional retraining of the oral cavity as we have outlined above, by presenting in greater detail the particularly spectacular case of young Caroline O.

At her birth, the pediatrician warned Caroline O.'s mother that her daughter had significant mandibular prognathism and advised her to seek advice as soon as possible. She attended many consultations during which she was advised to wait until her daughter was 15 years old and then have surgery to readjust the jaws by operating directly on the mandible.



She was told that any earlier treatment would be useless because of the high risk of recurrence during puberty. There was indeed considerable prognathism, with the lower incisors 5 mm farther forward than the upper incisors. The palate was narrow, the lower jaw markedly advanced and the upper jaw underdeveloped (see below).

Caroline aged 6 years 10 months

Treatment at 6 years and 10 months consisted of increasing the width and depth of the palate and slowing the development of the lower jaw (with a retractor followed by a Delaire mask), combined with functional retraining (particularly with regard to correct positioning of the tongue). At 7 years and 10 months, the results were already significant.

Banding treatment, which only began when the permanent teeth had erupted, consisted of fitting bands and brackets and extracting the four premolars. Treatment lasted 18 months and was completed when Caroline was 13 years old, i.e., well before the age at which a major surgical operation had been envisaged.

Orthodontic treatment helped to raise the angle of the two jaws relative to the base of the nose from -3 degrees at 6 years old to 1 degree at 12 years of age. Advancement of the upper jaw relative to the mandible can be clearly seen, while the height between the base of the nose and the chin remains unchanged.

The X-ray images below show the progress of correction and its stability. By stimulating growth in the upper jaw and slowing growth in the mandible the difference between the bones was corrected.



In October 2001, when Caroline was 19 years old, a final procedure was performed, minor surgery to allow one of the wisdom teeth (lower right) to grow properly by straightening its axis, which was twisted.

Surgery on the jaw was avoided by early treatment, despite significant bone malformation. Growth has not caused recurrence of the prognathism, contrary to what had been predicted to her mother. At 23 years old her face is harmonious and she has a lovely smile.

The photos below of Caroline at 23 years of age show the great stability of the treatment.

7 years 10 months

7 years 4 months

12 years 10 months 7 years 10 months 7 years 4 months



In Support of Functional Retraining Orthodontics

From the practical perspective, five important points, based on my long experience in this area, emerge from the analyses presented in this work:

The first is that there is considerable plasticity in natural processes so that, where correcting nature is concerned, orthodontic treatment is not only almost always possible but is even preferable to major surgical procedures.

The second is that in the case of major bony malformation, treatment must begin early to be able to influence both growth—either slowing it or, conversely, stimulating it—and reflexes, which are difficult to change. It is really important to remember that the earlier treatment begins, the better and more rapid will be the results.

The third point is that stabilization is only achieved when the teeth that have been repositioned correctly by orthodontic treatment or surgery are in an area where the forces exerted on them are in equilibrium or neutralized. This is necessary for them to be maintained in their new position. In other words, the system of forces that previously existed within the oral cavity and was the source of the malpositioning also needs to be modified. There is no point to repositioning teeth if the initial causes of their incorrect positioning are not treated as well.

Point four is that in any comprehensive orthodontic treatment involving the fitting of appliances to correctly reposition the teeth, it is essential to include functional retraining.



Some practitioners try to maintain straightened teeth artificially in the "correct" position without trying to rectify the negative forces that caused the deformation and result from bad habits developed over the years by the patient. If these forces continue to act adversely, they cause even more severe relapses.

Finally, functional retraining is based on two fundamental principles: the first is that the soft tissues of the mouth and jaw (in particular the muscles and the tongue) sculpt the hard tissues (the bone and teeth), modeling them by continuously acting on them, and the second, that the older individual should master mature swallowing, quickly abandoning the type required in an infant. He should no longer swallow by sucking, but should use the tongue muscles and those necessary for chewing.

Obviously the orthodontist often needs to work in close conjunction with the dentist in treating a patient. For example, when the teeth lack space in the jaw, the dentist should extract the premolars, so that the space made in the middle of the arch can benefit both the incisors and the wisdom teeth. The wisdom teeth are solid molars which are used when chewing. If necessary, a prosthesis such as a bridge can be fitted to them, whereas the premolars are fragile teeth which develop caries and break easily. It is thus preferable to sacrifice the premolars rather than the wisdom teeth, but unfortunately this is practiced by very few.

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SHORT GLOSSARY

Activator: An appliance for correcting maxillary prognathism.

Agenesis: Absence of the tooth buds of certain permanent teeth which do not appear after the milk teeth have fallen out.

Alveolar bone: The bone which fixes the teeth to the jaw.

Alveolar protrusion: The condition in which the teeth are inclined towards the exterior.

Alveolar retrusion: The condition in which the teeth incline inwards.

Alveolus: The bone directly surrounding the tooth, appearing and disappearing with it.

Ankylosed (tooth): Said of a tooth accidentally welded to the bone that cannot therefore erupt.

Antagonists: Said of identical teeth situated on opposite jaws.

Banding (treatment): A type of treatment

Basal bone: The hard bone of the jaw

Bruxism: Synonym for grinding the teeth, especially while sleeping.

Canines: The sharp teeth used to shred food.

Cleft lip and palate: Sometimes called "harelip." Denotes a malformation in which the palate is incompletely closed, so that the nose and mouth communicate with each other.

Contraction (of the dental arch): The deformation characterized by the upper molars being offset from their normal position and occurring to the inside of the lower molars.

Crib: An appliance for correcting open bite conditions.

Deglutition: The act of swallowing.

Delaire mask: An appliance used to correct mandibular prognathism.

Dental arch: The entire set of teeth on the jaw.

Dental consonants: The category of consonants to which [t], [d] and [n] belong.

Dental crowding: Insufficient space on the jaw for the teeth.

Diastema: Abnormal space between the teeth (widely spaced teeth).

Disharmony: The size of the teeth relative to the jaw is disproportionate.

Double protrusion of the incisors: A deformation of the upper and lower incisors, which project excessively.

Eruption: A tooth emerging from the gum.

Expansion (of the dental arch): A deformation characterized by the upper molars being offset from their normal position and occurring to the outside of the lower molars.

Extraction: The operation to remove a tooth.

Fricative: A type of consonant such as the sound [sh].

Germectomy: The extraction of tooth buds.



Impacted (canine): A canine poorly positioned in the gum which cannot erupt and develop normally.

Incisors: The front teeth, whose function is to cut or incise food (hence the name), cutting like scissors.

Infraocclusion: Said of a tooth which is unable to grow fully.

Intercuspation: The term indicating interlocking of molars.

Labial: Relating to the lips.

Labioversion: Synonym for alveolar protrusion.

Lingual: Concerning the tongue.

Malposition: Abnormal placement (generally of a tooth).

Mandible: Synonym for the lower jaw.

Masseters: The muscles of the jaw joint allowing the mouth to open and close. They are the most powerful muscles in the body.

Maxilla: Synonym for the upper jaw.

Maxillary contraction: When the palate is narrow, the upper molars are located to the inside of the lower molars, whereas normally they should circumscribe them so that together they correctly perform their role of grinding while chewing.

Maxillary expansion: When the palate is wide, the span of the upper molars is much wider than that of the lower, making it impossible to use the molars for chewing.

Microdontia: A malformation characterized by teeth which are too small and do not occupy all the space available in the dental arch.

Molars: The side teeth which are used to grind food, like millstones.

Multi-attachment device (treatment): Synonym for banding

Nasal: Related to the nose.

Nasal consonants: The category of consonants to which [m] (bilabial nasal) and [n] (dental nasal) belong.

Neuralgia: In this context, dental and cervicobrachial pain.

Occlusal: Relating to occlusion.

Occlusion: The term indicating the jaws being closed.

Odontoma: A supernumerary abnormal dental bud (which is not shaped like a real tooth).

Open bite: An abnormal gap between the two jaws on one side of the mouth (unilateral or lateral open bite), on both sides (bilateral open bite) or over the entire circumference of the teeth (total open bite).

Oral: Concerning the mouth.

Orthodontics: A term of Greek origin meaning literally "the science of straight teeth," this is the branch of dentistry responsible for correcting dental deformities.

Palate: The vault of the upper jaw.

Para-Andresen appliance: An appliance for correcting mandibular prognathism.



Peg-shaped teeth: Term occasionally used to describe small, rounded, pointed upper lateral incisors that impair the appearance of the smile.

Periodontal disease: Synonymous with "receding gums." A process weakening the implantation of the root of a tooth, which is no longer held firmly in the bone. It is due to resorption of alveolar bone and gum tissue.

Periodontal tissues: All the tissues enveloping the roots of the teeth.

Premolars: The intermediate teeth between the canines and the molars.

Prognathism: The deformation of one of the two jaws which has advanced too far forward relative to the other. Prognathism can be maxillary (the upper jaw is too far forward, producing "horse teeth") or mandibular (the lower jaw is too far forward, producing a protruding chin).

Quad Helix: An appliance for correcting a palate which is too narrow.

Receding gums: A synonym for periodontal disease.

Retained tooth: A tooth which cannot erupt from the gum because the tongue is interposed.

Retract: To cause a tooth that protrudes to be gently moved back towards the interior of the mouth.

Sibilants (consonants): The sub-category of consonants to which [s] and [z] belong.

Soft palate: The soft, movable part of the back of the palate.

Supernumerary teeth: Too many tooth buds. A congenital malformation.

Supraocclusion: Excessive overlapping of the upper incisors over the lower ones, sometimes completely covering them.

Temporomandibular: Relating to the articulation of the jaw.

Voiced consonants: The sub-category of consonants to which [b], [g] [v] and [z] belong.

Voiceless consonants: The sub-category of consonants to which [p], [k], [f], [s] and [sh] belong.

Wisdom teeth: The molars at the back of the jaw, the last teeth to appear on the dental arch. Also called the third molars.

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orthodontics for its patients, by dr claude mauclaire

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