development of naso maxillary complex / orthodontic courses by indian dental academy

Growth and Development of Nasomaxillary complex

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

www.indiandentalacademy.com

Source: JCO on CD-ROM (Copyright © 1998 JCO, Inc.), Volume 1983 Oct(669 - 679): JCO/lnterviews: Dr. Donald H. Enlow on Craniofacial Growth

DR. GOTTLIEBIs there good growth and bad growth? DR. ENLOW Well, no. Growth for any individual is "normal",

given the circumstances that exist for that individual. Growth is a process striving toward a state of functional equilibrium, and it is always responsive to the conditions that occur, unless pathology is involved. Most structural dysplasias, of course, are in "equilibrium".


Growth and development of Nasomaxillary complex

Anatomy Pre natal growth Post natal growth Theories Nasomaxillary remodeling Clinical implications Articles Summary


Area of Nasomaxillary Complex


AnatomySkeletal Tissues / Bones• Maxilla• Zygomatic• Palatine• Lacrimal• Vomer• Nasal spine, septum• Ethmoid• Sphenoid


AnatomySinuses

• Maxillary• Frontal• Ethmoid• Sphenoid• Nasal cavity

Radiological appearance


Anatomy

• External anatomy of the nose• Muscles attachments• Blood supply• Nerve supply• Lymphatic• Histological features• Relation to surrounding structures


Anatomy Of Maxilla Two maxillae articulate to form

1. Whole upper jaw.2. Roof of oral cavity.3. Greater part of buccal roof, floor and

lateral wall of nasal cavity and part of nasal bridge.

4. Greater part of floor of the orbit.5. Infratemporal and ptergyopalatine

fossae6. Inferior orbital and pterygomaxillary

fissures


Anatomy Of Maxilla Parts of Maxilla

1. Body –Large and pyramidal in shape .

2. Four processesFRONTAL

ZYGOMATICALVEOLARPALATINE

MAXILLA HOUSES THE LARGEST SINUS OF THE FACE THE MAXILLARY SINUS


Palatine process[maxilla]

Maxillary sinus

Frontal process

Maxillary process [palatine]

Alveolar process

Maxilla – Medial View

Horizontal plate of palatine


Nasal notch

Zygomatic process

ANS

Alveolar process

Maxilla - Lateral View

Frontal process


Maxilla


http://biology.clc.uc.edu/fankhauser/Labs/Anatomy_&_Physiology/A&P201/Skeletal/skull/maxilla_R_medial_PA281038.JPG

http://biology.clc.uc.edu/fankhauser/Labs/Anatomy_&_Physiology/A&P201/Skeletal/skull/maxilla_R_lateral_PA281037.JPG

Anatomy Of Maxilla


http://en.wikipedia.org/wiki/Image:Gray154.png

Anatomy Of Maxilla1. nasal 2. frontal 3. ethmoid 4. sphenoid 5. maxilla 6. horizontal process of

palatine 7. superior concha

(ethmoid) 8. middle concha (ethmoid) 9. inferior concha 10. sphenopalatine foramen 11. medial pterygoid plate 12. pterygoid hamulus of

medial plate


Anatomy Of Maxilla

At birth Adultwww.indiandentalacademy.com

http://en.wikipedia.org/wiki/Image:Gray161.png

Palatine bone


Palatine Bone

Horizontal platePerpendicular platePyramidal processOrbital processSphenoidal process


Zygomatic BoneCheek prominenceLateral wall of orbitInfratemporal fossa3 Foramen3 MusclesFrontal process – lateral palpebral, suspensory ligament.Temporal process


Zygomatic Bone


Lacrimal Bone

Smallest – most fragileArticulates with

Maxilla Frontal

boneEthmoid

boneNasal

concha


Nasal SeptumThe nasal septum is made up of the following: perpendicular plate of ethmoid vomer maxilla septal cartilage Muscles attached to Nasal bones – Procerus and nasalis.


Vomer

TrapezoidPosterior part of

nasal septum


EthmoidLateral masses with air cells ossified at birthNasal septum part ossifies during 1styrCribriform laminae ossify in 2nd yrCrista galli between 2nd &4thyrThese cartilages fuse with the lateral masses in the 6thyr


SphenoidThree parts

BodyLesser wingGreater wing

with the pterygoid processes fuse during the 1st yrSpheno-occipital synchondrosis begins after puberty


External nose• Covered by the integument, and lined by

mucous membrane • The bony frame-work occupies the upper part of

the organ; it consists of the nasal bones, and the frontal processes of the maxillæ.

• The cartilaginous frame-work (cartilagines nasi) consists of five large pieces cartilage of the septum, two lateral and the two greater alar cartilages, and several smaller pieces, lesser alar cartilages

The cartilage of the septum (cartilago septi nasi) is quadrilateral termed the septum mobile nasi. www.indiandentalacademy.com

External nose


Para nasal Sinuses

Maxillary sinusFrontal sinus

Ethmoidal sinusSphenoidal sinus


Maxillary sinusPyramidal shaped Base - lateral wall of the nasal cavityApex - into the zygomatic processAverage - 14.75ccFloor of sinus is above that of nasal cavity at birthSinus increases 3times ant-post & 5times in height and widthIn the inferior end of the uncinate process, is the ostium maxillare, or opening from the maxillary sinus


Frontal sinus• The Frontal Sinuses (sinus frontales)• Behind the superciliary arches• Average measurements are as follows:• Height, 3 cm• Breadth, 2.5 cm• Depth from before backward, 2.5 cm• Opens into middle meatus of the nose

through the frontonasal duct • Absent at birth, they are generally fairly

well developed between the seventh and eighth years

• Reach their full size after pubertywww.indiandentalacademy.com

Ethmoidal sinusThe Ethmoidal Air Cells (cellulae ethmoidales)Ethmoidal labyrinth and completed by the frontal, maxilla, lacrimal, sphenoidal, and palatine bonesThree groups, anterior, middle, and posteriorThe anterior and middle groups open into the middle meatus of the noseThe posterior cells open into the superior meatus Develop during fetal life.


Sphenoidal sinus• The Sphenoidal Sinuses (sinus

sphenoidales)• Average measurements• Vertical height, 2.2 cm• Transverse breadth, 2 cm• Antero-posterior depth, 2.2 cm• Communicates with the

sphenoethmoidal recess • Minute cavities at birth• Development takes place after puberty


Nasal CavityThe nasal chambers are situated one on either side of the median planeThey open in front through the nares, and communicate behind through the choanæ with the nasal part of the pharynxNares are somewhat pear-shaped apertures, each measuring about 2.5 cm - antero-posteriorly and 1.25 cm - transversely at its widest part Choanae are two oval openings each measuring 2.5 cm. in the vertical, and 1.25 cm. in the transverse direction in a well-developed adult skull


Radiological appearance


Indices• Cephalic index• Total facial index• Upper facial index• Nasal index• Orbital index• Palatal index• Gnathic index


Para nasal Sinuses


Relations with surrounding tissues

• Infratemporal fossa• Ptergyopalatine fossa• Basicranium• Middle ear• Oral cavity• Nasopharynx


Muscle attachments


Blood vessels, Nerves & Lymphatics

External carotid arteryV & VII cranial nerveSubmandibular lymphnodes


Histological Appearance

Olfactory cells, olfactory hairs and glands of Bowman, are identical in structure with serous glands The epithelial cells of the nose, fauces and respiratory passages play an important role in the maintenance of an equable temperature


Development of Embryo

• 1st week – 3rd week• Ovum Zygote Blastocyst Gastrula

Neurulation


Development of Embryo 4th weekSomitesNeural tube formation24th day 1st and 2nd arch are

distinct26th day – 3 pairs of

branchial arches otic pits appear 4th pair of branchial arches and lens placodes are visible

• C shaped curvature of the embryo


Branchial Arches 1st Arch - Mandibular Arch• 2 prominences - mandibular prominence

- maxillary prominence• Bones – mandibular,

maxilla, zygomatic squamous part of the temporal bonemalleusincus


Branchial Arches 1st Arch - Mandibular Arch• Muscles of mastication• Mylohyoid and anterior belly of digastric• Tensor tympani• Tensor veli palatine Anterior ligament of malleus Sphenomandibular ligament Trigeminal nerve except the opthalmic

division Maxillary artery Meckel’s cartilage


Branchial Arches2nd Arch - Hyoid Arch• Bone - hyoid

stapes styloid process lesser cornu of hyoid upper part of body of

hyoidwww.indiandentalacademy.com

Branchial Arches 2nd Arch - Hyoid Arch• Muscles of facial expression

stapedius stylohyoidposterior belly of digastricstylohyoid ligament

Facial nerve Stapedial artery Reichert’s cartilage


Branchial Arches Third Arch• Bone – greater cornu and the inferior

part of the body of the hyoid bone• Stylopharyngeus Glossopharyngeal nerve Common carotid artery Internal carotid artery Carotid body


Branchial Arches Fourth Arch• Thyroid cartilage

corniculatecunieform cartilage

• Muscles – cricothyroid, constrictors of pharynx, palatopharyngeus, uvular muscles of soft palate, palatoglossus

Superior laryngeal nerve Left – arch of aorta & Right –

subclavian and brachiocephalic arteries


Branchial Arches Sixth arch• Cricoid cartilage

arytenoid cartilage• Recurrent laryngeal nerve


Pre natal growth and development


Prenatal embryology

• Face - Upper - Frontonasal - Middle - Maxillary - Lower - Mandibular

Organizing centersProsencephalic - Upper third of faceRhombencephalic - Middle third of

face

1/3rd Prominence


4th week IUL

• Shallow depression - Primitive mouth - Stomodeum

• Floor of the stomodeum is formed by the Buccopharyengeal membrane


Pre-natal growth At fourth week of of IUL- 1.migration of neural crest cells 2.formation of brachial arches

STOMODEUM

FRONTONASAL MAXILLARYMAXILLARY

MANDIBULAR MANDIBULARwww.indiandentalacademy.com

Medial nasal process

Lateral nasal process

Maxillary process

Mandibular process


Maxillary and Mandibular processes-

first branchial arch Frontonasal processes- downward

proliferation of mesenchyme of developing brainMedial nasal Lateral nasal

Mesenchyme of first arch

maxilla

palatine

mandible

zygomatic

Part of temporalwww.indiandentalacademy.com

Nasal process

Median nasal

process

Lateral nasal

process


At Seventh Week IUL- 1.Formation of upper lip 2.Intramembranous Bone

ossification Takes Place 3.Formation of Nasal Septum 4.Nasolacrimal Duct 5.Formation of Primary Palate


At Seventh Week IUL Primary ossification center -for

each maxilla at termination of infraorbital nerve above canine tooth dental lamina.

Secondary centerzygomaticorbitonasal

intermaxillarynasopalatine


At Eighth Week IUL Two intermaxillary ossification centers

generate the alveolar ridge and primary palate

Intramembranous ossification centers appear for;

-Nasal and lacrimal bones.-Medial pterygoid plate of sphenoid.-Vomer.-Zygomatic bone


Anteroposterior maxillo- mandibular relationship approaches that of newborn infant

Maxilla increases in height

Twelfth Week


Growth of palate

1st trimester-narrow 2nd trimester-moderate width 3rd trimester- wide Breadth>length Height changes less dramatic


Growth of palate

• Two primordia, primary palate and secondary palate


Pre-natal Growth and development of palate

Formation of primary and secondary palate

Elevation of palatal shelves

Fusion of palatal shelves


Early palate formation 28th day of IUL -disintegration of buccopharangeal

membrane stomadeal chamber

Horizontal extensions

Oral cavity

Nasal cavity

2 palatal shelves

Single primary palatewww.indiandentalacademy.com

Structure of palate

PALATOGENESIS

Secondary palatePrimary palate

5 TH week IUL

12 TH week IUL

6 9

CRITICAL PERIODwww.indiandentalacademy.com

Primary palateFrontonasal process

Medial nasal

Mesenchyme

Wedge shaped mass between internal surface of maxillary prominence

Primary palatePre-maxilla


Primary palate

Primary palate


Secondary palate

2 horizontal mesenchymal projections

Maxillary prominence

Lateral palatine process

Fuse-With each otherPrimary palateNasal septum

Secondary palatewww.indiandentalacademy.com

Secondary palate

Palatal Shelveswww.indiandentalacademy.com

Elevation of palatal shelves At 6 weeks1. Tongue {undifferentiated tissue} pushes dorsally2. palatal shelves become vertical3. Elevation occurs from vertical to

horizontal position


Elevation of palate

Nasal septum

Palatal shelves

Tongue

Histological section


At 8 weeks

Elevation of palatal shelves

Muscular movement

Pressure differences

Biomechanical transformation

Intrinsic shelf force

Differential mitotic growth

Withdrawal of embryo’s face

Vascular changes

Increase in tissue turger


Elevation of head and lower jaw


Fusion of palatal shelves


Fusion of palate

Incisive foramen

Mid palatine raphe


Formation of palate [summary]Primordiu

m ofFormed by

Derived from

Primary palate

Secondary

palate

Pre maxill

a

Hard and soft

palate

Median palatine process

Lateral palatine process

Frontonasal process

Maxillary process


Ossification of the palate• Premaxillary centres• Primary ossification centres of

each palatine bone• Y shaped midpalatal suture• T shaped midpalatal suture• No ossification at the soft palate

region

8th wk

10th wk

Childhood


Musculature of palate

Tensor veli palatini 40 days 1st arch Palatopharangeous 45 days Levator veli palatini 8th week 2nd

arch Palatoglossus 9th week Uvular muscle 11thweek 2nd

arch


Growth in dimensions

Length - 7-8 weeks IUL Width - 4th month onwards

heightwidthlength

Arched palate


Growth in dimensions Pre natal life (appositional growth in the alveolar

margin)

length > width

At birth (appositional growth in the maxillary tuberosity)

length = width

Post natal life width > lengthwww.indiandentalacademy.com

Factors affecting growth of palate

Elevation of head and lower jaw Oxygen and nutritional deficiency Excess endocrine substances Drugs Irradiation Vascularity

teratogens


Maxillary sinus PRE NATAL lateral evagination of mucous

membrane in middle meatus –3rd month IUL

AT BIRTH 2mm -long, 1mm in width +

height PNEUMATISATION

PRIMARY SECONDARYwww.indiandentalacademy.com

Neonatal Skull


Cleft Lip and Palate


Genesis of cleft lip and palate Associated with more than 150

syndromes Aetiology• Mutant gene or chromosomal

aberrations - Monogenic - Polygenic


Etiology of cleft lip / palate

Infectious agents

Irradiation

Drugs

Nutritional deficiency

Excess hormones

Smoking and alcohol


• Separation due to wide growing brain and cranial floor

• Separation due to tongue• Biochemical or tissue barrier

intercedes between the fusing parts

• Primary failure in the fusion

Genesis of cleft


Cleft lip usually seen at the philtrum and the lateral part of the upper lip

Harelip

Bifid nose


Prenatal anomalies

Formation of germ layers

Day 17

Fetal alcohol syndrome[mid face deficiency]Migration

and proliferation of cell population

Day 19-28

Treacher Collin syndrome


Prenatal anomalies

Primary palate formation

28-38 days

Cleft lip /cleft palate other facial clefts

Secondary palate formation

42-55 days

Cleft palate/synostosis Crouzon syndromeEpithelial pearlsTorus palatinusHigh arched palatewww.indiandentalacademy.com

Other syndromes• Downs syndrome• Hurlers syndrome• Cebocephaly• Scaphocephaly• Apert syndrome• Cyclops• Van der Woude syndrome• Craniostenosis


ANOMALIES OF PALATE Epithelial pearls


ANOMALIES OF PALATE

Torus palatinus


ANOMALIES OF THE PALATE

High arched palate

MARFANS SYNDROME CROUZON

SYNDROMECLEIDOCRANIAL DYSOSTOSIS


Genesis of cleft palate Delay in shelf elevation Disturbance in

mechanism of shelf elevation

Failure of shelves to contact due to lack of growth

Failure to displace the tongue during closure [Pierre Robin syndrome]


ANOMALIES OF PALATE Cleft palate

Failure of fusion of the lateral palatine process with each other or with the median palatine processwww.indiandentalacademy.com

Genesis of cleft palate Failure to fuse

after contact as epithelium does not break down

Rupture after fusion

Defective merging www.indiandentalacademy.com

Types of cleft palate

Bifid uvula

Unilateral cleft palate

Bilateral cleft palatewww.indiandentalacademy.com

Bilateral cleft palate

Bifid uvula

Unilateral cleft palate


Classifications Davis and Ritchie’s : (1922)

Group I – prealveolar clefts

Group II – postalveolar clefts : cleft involving hard and soft

palate

Group III – Cleft of both primary and secondary palate


Veau’s classification : (1931)

A. Cleft lip

class I : U/L notching of vermillion border, not extending into the lip.

class II : cleft extending into the lip, but not including the floor of the nose.

class III: extending into the floor of the nose.

class IV: any b/l cleft of the lip, whether incomplete or complete.


• B. Cleft palate

• class I : soft palate

• class II : soft/hard palate extending no further than incisive foramen

• class III: complete u/l cleft, extending from uvula to incisive foramen, then

deviating to one side

• class IV: two clefts extending forward from the incisive foramen into the alveolus


Fogh Anderson’s Classification (1946)

1. Hare lip cleft

2. Hare lip cleft associated with cleft palate

3. Isolated cleft palate


Kernahan / Stark’s (1958)

1. Cleft of primary palate

2. Cleft of secondary palate

3. Cleft involving both primary and secondary palate.


Interdisciplinary approach• Genecist• Orthodontist• Oral Maxillofacial Surgeon• Prosthodontist• Plastic Surgeon• Paediatrician • Social workers• Psychiatrist / Psychologist • Speech Pathologist / Therapist• Audiologist• Nursing serviceswww.indiandentalacademy.com

Stage I

• Maxillary Orthopedic stage – Birth to 18 months

• Mc Neil – 1950 prosthetic devices• Obturator

False plateMaxillary cross arch stabilityMaxillary orthopedic molding


• Premaxillary orthopaedics – birth to 5 months

• 1686 – Hofman• Use of headcap and premaxillary

strap to reposition the premaxilla


• Cheiloplasty• Rule of Tens

10 weeks of age10 pounds of body weight10 grams of hemoglobin


• Maxillary orthopaedics – 3 to 9 months

Obturator to provide cross arch stability


Stage II - Primary dentition - 18 months to 5 yrs

Stage III - Late primary or mixed dentition – 6 to 11 yrs

Stage IV – Permanent dentition – 12 to 18yrs


Grafting procedures• Palatoplasty - 1 to 2 yrs• Primary bone grafting < 2 yrs• Early secondary bone grafting – 2 to 4 yrs• Secondary bone grafting – 6 to 15 yrs• Late secondary bone grafting – Adult

• Graft from RIB - 2cms is harvested


Clinical features of cleft palate

Feeding problems particularly in infants in whom suckling process demands intact palate

Nasal regurgitation/nasal twang in voice

Collapsed arch

Difficulty in speech and swallowingwww.indiandentalacademy.com

Dental deformities• Natal or neonatal teeth• Congenitally missing teeth• Supernumerary teeth• Ectopic eruptions• Altered tooth morphology• Deficient alveolar bone support• Rotations, deviations in axial root

inclinations• Posterior cross bite• Mobile and protuberant premaxilla• Convex profile


Post natal growth of Nasomaxillary

complex


• General features• Three dimensional growth of maxilla

Height (Vertical)Width (Transverse)Length (Ant-Post)

• Theories of growthSuturalCartilaginousFunctional matrix theory

• Key factors in Nasomaxillary remodelling www.indiandentalacademy.com

Displacement• Primary

displacement

• Secondary displacement


Reversal line• Directions of growth

sequentially undergo reversals

• A reversal line showing the crossover between resorptive and depository growth fields seen in microscope

• Factors affecting reversalshape of bonemuscle attachmentsrotationsgrowthfeilds


Post natal growth of maxilla Surface remodeling

Displacement

CRANIAL BASE MAXILLA

apposition

resorption

MOSS

Transformation

Translation

SUTURES


Post natal growth of maxilla Mechanism of growth• Sutural • Nasal septum• Surface apposition and resorption on

periosteal and endosteal surfaces• Alveolar process • Spheno occipital synchondrosis


• In contrast to cranial base maxilla is dominated by intra membranous ossification

• Endochondral bone growth seen at the ethmoid bone and nasal septum


Surface apposition


Spheno occipital synchondroses


Post natal growth


Post natal growth At Birth

Hard palate : length = widthmaxillary sinus : not visible radiographically

1 – 2 years

Extensive remodeling descent of palate /enlargement of nasal cavity

Mid palatine suture growth ceases

No synostosiswww.indiandentalacademy.com

Post natal growth

Mid palatine suture starts closing at 9- 10 years

RME Best done between 9-14 yrs

THE MIXED DENTITION YEARS

Growth in width of the dental arch anterior to the first molar

Ceases by 5-6 yrs

Inter canine width completed

12 yrs - females

18 yrs - males


Post natal growth

The depository growth potential of the tuberosity allows for arch expansion by moving the teeth posteriorly into the area of bone deposition

Extensive scope for growth modification before adolscent growth spurt

THE MIXED DENTITION YEARS


Post Natal Growth THE EARLY PERMANENT DENTITION YEARS

•Growth modification still possible in boys

•RME can still be tried till 12 -15 yrs

•>15 years complete closure[synostosis]

Orthognatic surgerywww.indiandentalacademy.com

Age changes All para nasal sinuses increase in

size Vertical height decreases

Vertical changes > AP > width Soft tissue changes > skeletal Nose growth continues till 25 years Inclination of palatal plane

increases[post downwards]

Alveolar process resorbed

Tooth loss


Effects of Dentition and Occlusion

• Bimolar width in the 1st molar region correlates- Vertical growth of maxilla- Growth in the midpalatal suture- growth in height


Effects of Dentition and Occlusion

• Maxilla drifts – 5mm forward in molar region (by adolscence)- 2.5mm in incisor region

• Shortening of the arch perimeter – associated with eruption of 2nd molar

• Initiation of eruption of 3rd molar occurs after the greatest shortening of length in the maxillary dental arch

• Shortening of anterior segment – mesial drift of teeth – crowding of ant segment – convergence and narrowing of the bone basewww.indiandentalacademy.com

Post natal growth of maxilla

Growth in height vertical

Growth in width transverse

Growth in length A - Pwww.indiandentalacademy.com

Vertical growth • Bjork and Skieller implant

studies - height increases because of sutural growth toward the frontal and zygomatic bones- appositional growth in the alveolar bone, floor of orbit, on hard palate and resorption on nasal floor


HEIGHT

Deposition on the oral side

Resorption on the nasal side

ENLOW AND BANG ‘V’ PRINCIPLE


V principle of Bang and Enlow

Entire ‘v’ shaped structure moves in a direction towards the wide end of the ‘v’

Remodeling of palate


H EIGHT

APPOSITION IN THE ALVEOLAR PROCESS

ERUPTION OF TEETHwww.indiandentalacademy.com

Sagittal view

Coronal view

HEIGHT - V’ PRINCIPLE


Primary

displacement

HEIGHT


WIDTH Finished earlier in postnatal life

WIDTH GROWTH IN MID PALATINE SUTURE

REMODELING IN THE LATERAL SURFACE OF ALVEOLAR PROCESS

Mutual transverse rotations of maxillary halves give palate ‘u’ shape www.indiandentalacademy.com

WIDTH• This growth mimics the general

growth curve

• Mutual transverse rotation of the two maxillae results in more separation of the halves in the posterior than the anterior segment


LENGTH Begins rapidly in the 2 nd year of life

Maxillary tuberosity

Palato maxillary suture

primary

secondary

displacement


LENGTH• Resorption in the anterior region of

the maxilla• Maxilla rotates in relation to the

anterior cranial base• Bjork and Skieller implant studies

have shown that anterior surface is stable sagittally


Timing

• Alveolar process – eruption of teeth• Overall height – along with

- Vertical growth of mandible- General body growth curve


Compensatory mechanism• Narrow palate – alveolar process

compensates for width and heightDeep bite – Occ plane parallel to mandibular planeLong anterior surface – Steep occlusal plane

• Adaptive nature Class I molar relation though skeletally retrognathic

• Orthodontic correction totally dependent on the adaptive capacity of alveolar process remodelling


Theories of growth

SUTURAL THEORY

CARTILAGENOUS THEORY

FUNCTIONAL MATRIX HYPOTHESIS


Sutural Theory Sutures have innate

growth potential Push bones apart Oblique in nature Sliding effect Resultant thrust in

the anterior and inferior direction

Weinman & Sicher


Sutural Theory

• Shortcomings- Bone tissue in not capable of growth in a

field that requires level of compression needed to produce a pushing type of displacement

- Suture is essentially a ‘tension’ adapted tissue

- Sutures do not have inbuilt growth potential


Cartilagenous theory Nasal septum – innate growth potential

Thurst effect – septomaxillary ligament – growth in fields of compression

More of forward and downward force than vertical

Bone enlarges at the sutures in response to the tension created by displacement

Surgical removal of Nasal septum…

Scott


Removal of nasal septum –mid face deficiency


Cartilagenous theory

Shortcomings • Nasal septum functions to support the roof of the

nasal chamber• Doesn’t displace the palate by itself

Reasons• Source of maxillary displacement is multifactorial• Exptl studies merely show that groeth process

functions in its absence rather than in its presence


Functional matrix hypothesis

Basal body Infraorbital

nerve

Orbital unit Eyeball

Nasal unit Septal cartilage

Alveolar unit Teeth

MossSKELETAL UNITS FUNCTIONAL MATRIX


Functional matrix hypothesis

Height

Enlarging orofacial capsule

Remodelling changes in the orbit

Soft tissues give control signals to genic tissues

response seen in the hard tissue www.indiandentalacademy.com

The Counterpart Analysis

Growth of any given facial or cranial Growth of any given facial or cranial part relates specifically to other part relates specifically to other structural and geometric counterparts structural and geometric counterparts in the face and cranium” – Enlowin the face and cranium” – EnlowAs the cranial flexure decreases, the maxilla is translated or displaced forward and downward to give a more protrusive maxillary position.www.indiandentalacademy.com

The Nasomaxillary Complex Remodeling

• The Lacrimal Suture• The Maxillary tuberosity • Key ridge• Vertical drift of teeth• Nasal airway• Palatal remodelling• Downward maxillary displacement• Maxillary sutures• The Cheekbone and Zygomatic Arch• The paranasal sinuses• Orbital Growth


Lacrimal bone• Bounded by sutural connective tissue• Undergoes remodelling rotation – medial superior

part remains with the nasal bridge, - inferior part moves outwardly with the ethmoidal sinuses

• Provides slippage of multiple bones along sutural interfaces ‘ perilacrimal sutural system’

• Maxilla slides downwards along its orbital contacts• Developmental gridlock would develop without this

system


Maxillary tuberosity Established by the posterior

boundary of anterior cranial fossa Helps in posterior and horizontal

lengthening of archAnterior displacement= posterior lengthening

lateral widening downward deposition Contributes to maxillary sinus

enlargementwww.indiandentalacademy.com

Key ridgeVertical crest below the malar protuberence ‘muzzle’Reversal occurs at the key ridgePosterior - appositionAnterior - resorption


Vertical drift of teeth• Vertical drift – significant intrinsic

growth factor• provides intramembranous bone

remodelling • Moves the tooth in its socket – usually

called extrusion• mesial drift well known process –

‘Vertical drift’ not a part of everyday vocubulary


Nasal airwayLining surface of bony wall and floor

Resorptive(except olfactory fossae)

Downward relocation of palate

Lateral and anterior expansion

Downward cortical remodelling of entire anterior cranial floor & lateral and inferior depositions on ethmoidal conchae www.indiandentalacademy.com

Nasal airway Ethmoidal conchae - lateral + inferior

deposition- medial + superior resorption

Inter nasal septum- lengthens vertically at sutural junctions


Palatal remodelling• V principle• Bone deposition on the inside of the

arch• Growth along the mid palatal suture• Grows inferiorly exchange of old

palate for new hard and soft tissues occurs


Downward maxillary displacement

• Primary displacement of the ethmomaxillary complex inferiorly

• New bone is added at all sutures and these sutures accompany displacement produced by the soft tissues


Downward maxillary displacement

• The balance of > or < growth in posterior and anterior maxilla is due to clockwise/counterclockwise rotatory displacement caused by downward and forward growth of the middle cranial fossa

• Nasomaxillary complex undergoes

compensatory remodelling rotation to sustain its position relative to the vertical reference line and to the neutral orbital axis


Maxillary sutures• Sutures slide or slippage of bones along the

interface

• Remodelling and relinkage of the collagenous fiber connections within the sutural connective tissue causes the displacement process


Cheek and zygomatic bone• Posterior side of malar protuberence within the

temporal fossa is depository• Cheek bone relocates posteriorly as it enlarges• Posterior relocation slows after dental arch

length is achieved during childhood• Zygomatic arch moves laterally by resorption

on the medial side• Zygoma and cheekbone complex are displaced

anteriorly and inferiorly in the same directions as the maxilla


Zygomatic regionPosterior relocation

anterior

posteriorIncrease in height

frontozygomatic

Inferior border

Lateral growth

displacementZygomaticotemporal [anterior]Frontozygomatic [inferior]


Maxillary sinusAge changesExpands - 2mm vertically 3mm A-P - every year> in size - resorption in walls + alveolus


Maxillary sinus POST NATAL All internal

surfaces resorption

[expect medial]

Rapid continuous downward growth

close proximity to buccal maxillary teeth


Orbital growth• Most of the lining roof and floor are depository• Lateral wall remodels by deposition and medial by

resorpition• i)Forward remodelling of the nasal and superior

orbital rim,• ii) backward remodelling of the inferior orbital rim and

the malar area • iii) downward remodelling of the premaxillary region• combine to produce rotation and alignment of the

midface and upper facial regions


References Contemporary orthodontics - PROFFIT Principles and practice of orthodontics - GRABER Essentials of facial growth - ENLOW Craniofacial embryology - SPERBER The developing human - MOORE and PERSAUD Oral histology and embryology - TENCATE Handbook of orthodontics – MOYERS A Text Book of Oral Pathology – SHAFER, HINE,

LEVY JCO/lnterviews: Dr. Donald H. Enlow on

Craniofacial Growth Volume 1983 Oct (669 - 679)


References Moyers – 3rd edition Dentistry for child and adolescent -

MAC DONALD Clinical pedodontics - FINN Color atlas of Embryology-

MOORE,PERSUAD Hand Book of Facial Growth-ENLOW Grays Anatomy – 38th Edition Previous Seminars By - Dr.Chatura

Hegde, Dr Ravi Tej, Dr.Harshavardhan Kidiyoor and Dr Jaya Kothari.


Ability is what you’re capable of doing. Ability is what you’re capable of doing. Motivation determines what you do.Motivation determines what you do.Attitude determines how well you do Attitude determines how well you do

it.it. - Lou Holtz- Lou Holtz


QUANTITATION OF MAXILLARY REMODELING

Uniform displacement of all 3 pts in vertical direction [downward displacement –0.3mm/year]

Horizontal direction posterior displacement of all 3 pts [however the displacement of PNS was greater than ANS and pt A ]

THE INCREASE IN LENGTH IS PRIMARILY BECAUSE OF GROWTH IN POSTERIOR BORDER

Sheldon Baumrind,Edward Korn

AJO JAN 1987


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