GOOD MORNING

PRESENTED BY:DEVENDRA PAL SINGH

CONTENTSy y y y y y y y y y y y y

INTRODUCTION GROWTH AND DEVELOPMENT GROSS ANATOMY OF TONGUE ---- MUSCLES OF TONGUE ---- BLOOD SUPPLY ---- INNERVATION OF TONGUE ---- TASTE BUDS HISTOLOGICAL FEATURES AGE CHANGES PATHOLOGY OF TONGUE APPLIED ANATOMY SUMMARY AND CONCLUSION REFERENCES

INTRODUCTIONTongue is a mobile muscular organ situated in the floor of mouth and is associated with functions of stomatognathic system like taste, speech, mastication and deglutition.

y it bulges upwards from the floor of mouth and its

posterior part forms the anterior wall of the oral part of pharnyx. It is covered by stratified squamous epithelium and consist of mass of striated muscles interspersed with a little fat and numerous glands.

y It is separated from teeth by alveolingual sulcus which

is filled in by the palatoglossal fold posterior to last molar tooth and extends beneath its free anterior third. Smooth mucous membrane in sulcus passes from the root of tongue across the floor of mouth on to the internal aspect of mandible and becomes continuous superiorly with gums.

Functionsy It acts as an organ of taste, and helps in mastication,

deglutition and speech. y In some lower animals (e.g. dog) it is used for thermoregulation by panting. y Sometimes tongue-prints displaying the pattern of lingual papillae are used in medico-legal purposes for personal identification. y Clinically, it acts as a mirror in various disturbances of alimentary tract. y It is sometimes utilised in gestures and postures of facial expression.

Knowledge of anatomy and functions of tongue is essential to understand morphological and functional changes in tongue associated with partial and complete edentulism

Recognition, understanding and incorporation of

mechanical, biological and physical factors are necessary for optimal prosthetic success,as tongue plays one of the significant key role in affecting stability and retention in prosthesis fabrication.

DEVELOPMENT OF TONGUEy The anterior 2/3rd of the tongue is formed by the

fusion of

y 1. Tuberculum impar y 2. Two lingual swellings. y The posterior 1/3rd is formed from the cranial part of

the hypo branchial eminence , it is a swelling seen in medial relation to the second, third, and fourth arches.

FOURTH WEEKy The tongue develops at about 4 weeks of intrauterine

y y y y

life in relation to the branchial arches in the floor of the mouth The medial most part of the mandibular arch proliferates to form two lingual swellings . These swellings are separated by another swelling , tuberculum impar , which appears in the midline Immediately behind the tuberculum impar the epithelium proliferates to form a downward growth The site of this growth is marked by an depression called foramen caecum

y The mesenchyme of 3rd arch rapidly grows over 2nd ,so

2nd arch is excluded from further involvement.y The hypobrachial eminence gives rise to mucosa

covering the root or posterior third of tongue.y The tongue separates from floor of mouth by a down

growth of ectoderm around its periphery, which subsequently degenerates to form the lingual sulcus and gives mobility to the tongue.

GROSS ANATOMY OF TONGUEy DORSUM y VENTRAL SURFACE y PAPILLAE y MUSCLES y BLOOD SUPPLY y LYMPHATICS y NERVE INNERVATION y TASTE BUD

ANATOMY OF TONGUEDIVIDED INTO TWO PARTSy SUPERIOR( DORSAL) y INFERIOR ( VENTRAL)

EXTERNAL FEATURES CONTAINSy TIP y BODY y ROOT

BODY IS FUTHER DIVIDED INTO:y Curved upper surface or Dorsum (with oral and

pharyngeal part)

y Inferior surface(confined to oral part only)

y DORSUM OF TONGUE y Extends from tip of tongue to anterior surface of the epiglottis. It is separated into palatine and pharyngeal part by a v shaped sulcus terminalis, the apex of which points posteriorly and is marked by a pit foramen caecum. y Thick mucous membrane of palatine part is roughened by the presence of papillae. In the pharyngeal part it is smooth, thin and finely nodular due to lymph follicles

y ORAL PART ALSO KNOWN AS PAPILLARY PART

y PHARYNGEAL PART ALSO KNOWN AS

LYMPHOIDAL PART

Oral or pappilary part of tongue is placed on the floor of mouth. Its margins are free and in contact with gums and teeth. The superior surface shows a median furrow and is covered with papillae which makes it rough , whereas the inferior surface is covered with smooth mucous membrane

y which shows a median furrow called frenulum

linguae and on either side of frenulum is a prominence produced by deep lingual veins. More laterally to this fold is plica fimbriata that is directed forwards and medially towards tip of tongue.

PHARYNGEAL PARTy It constitutes the base and lies posterior to the

palatoglossal arches. y The pharyngeal part of the tongue is devoid of papillae, and exhibits low elevations. There are underlying lymphoid nodules which are embedded in the submucosa and collectively termed the lingual tonsil.

LINGUAL PAPILLAEy Are discrete structures or appendages

of keratinized epithelium and lamina propria.

The four types of papilla are :y FILIFORM y FUNGIFORM y FOLIATE y CIRCUMVALLATE

First three are associated with taste buds.

y All except the filiform papillae bear taste buds. y

Papillae are best observed when the tongue is dry

FILIFORM PAPILLAE y These are most common lingual papillae located on the body of dorsal surface of tongue. They are shaped like fine pointed cones of 2 to 3 mm,with tips naturally turned towards the pharynx. They give dorsal surface of tongue a velvety appearance and are present in rows parallel to sulcus teminalis posteriorly. These are sensitive to changes in the body. y Histologically Increased amount of keratin is noted and also no taste buds are present in epithelium of these papillae

FUNGIFORM PAPILLAE y These are smaller, numerous,reddish dots that on closer inspection reveals slightly elevated mushroom shaped appearance. Though they are less numerous than filiform papillae but are present on tip and margins of tongue. y Histologicaly: a thin layer of ortho and parakertinisation of epithelium overlying a highly vascular lamina propria, with taste buds located in the superficial portion of epithelial layer.

FOLIATE PAPILLAEy These are 4 to 11 vertical ridges parallel to one another

on the lateral surface of tongue

CIRCUMVALLATE PAPILLAE y These are large sized;1-2 mm diameter; these are situated immediately in front of sulcus terminalis. Each papillae is like a cylindrical projection and is surrounded by trough into which ducts of serous Von Ebner s gland open

MUSCLES OF TONGUEDIVIDED INTO TWO GROUPS: y EXTRINSIC GROUP y INTRINSIC GROUP

INTRINSIC MUSCLES(muscles that occupyupper part of tongue and are attached to submucous fibrous layer)

EXTRINSIC MUSCLES y (connect tongue to :mandible) y :hyoid bone y :styloid process y :palate

y Tongue is divided into right and left halves by a middle

fibrous septum. Each half has four intrinsic and four extrinsic muscles. y Intrinsic muscles are located wholly within the tongue y Extrinsic muscles have attachments outside the tongue y Basic tongue movements are controlled by its attached extrinsic musculature

INTRINSIC MUSCLESySuperior longitudinal: It shortens thetongue and makes the dorsum concave,this muscle lies beneath mucous membrane.

yInferior longitudinal: It shortens thetongue and makes the dorsum convex,this muscle lies between genioglossus and hyoglossus.

y Transverse: It helps in narrowing and elongationof tongue(increase in height of tongue) ,this muscle extends from median fibrous septum towards margins.

y Verticalis: It broadens the tongue and causesflattening of tongue,this muscle is present at the borders of tongue in anterior part.

EXTRINSIC GROUPBasic tongue movements are controlled by its attached extrinsic muscules and to a certain extent by mandibular movements. The intrinsic muscles creates change in form and shape of tongue, such as elevation or depression of the blade or tip. The intrinsic musculature has the potential to make discrete changes in the shape and position of tongue independent of either mandibular movements or contraction of extrinsic musculature.(

Genioglossus:y It connects tongue to the mandible. It is a fan shaped

muscle and forms the main bulk of tongue. It arises from genial tubercle of mandible,from here fibres fan out and run backwards. y The upper fibres are inserted into tip of tongue and helps in retracting the tip. Middle fibres are inserted into dorsum of tongue and helps in depressing the tongue. Lower fibres inserts into hyoid bone and pulls the posterior PART(protrusion of tongue)

Hyoglossus:y Fibres of this muscle arise from greater cornu and

lateral part of body of hyoid bone, these run upward and forward to insert on side of tongue. It depresses tongue makes the dorsum convex and specifically it retracts the protruded tongue.

Styloglossus:y This muscle arises from the tip and anterior surface of

styloid process as well as from upper end of stylohyoid ligament. It passes downward forward to insert into side of tongue intermingling with fibres of hyoglossus. During swallowing it pulls the tongue upwards and backwards.

Palatoglossus:y Its fibres originates from oral surface of palatine

aponeurosis and inserts into side of tongue at junction of oral and pharyngeal part. This muscle pulls up the root of the tongue, approximates the palatoglossal arches and thus closes the oropharyngeal isthmus.

INFERIOR SURFACE OF TONGUEInferior surface and sides of tongue are covered with smooth, thin mucous membrane. In the midline anteriorly the mucosa is raised into a sharp fold which joins the inferior surface of tongue to the floor of mouth(frenulum linguae)

On each side of the frenulum:deep lingual vein is seen through mucous membrane and lateral to it is a fringed fimbriated fold of mucous membrane. On the floor of mouth is opening of submandibular duct on the sublingual papilla. Passing posterolaterally from this is the rounded sublingual fold on which opens number of ductules of sublingual gland. SIDES OF TONGUE(blade)

y On the side of tongue , anterior to lingual attachement

of the palatoglossal arch are five short vertical folds of mucous membrane (folia linguae). These carry taste buds and are much better developed in animals like rabbit , hare.

BLOOD SUPPLY OF TONGUEARTERIAL SUPPLY: y is from lingual artery, which is branch of External Carotid Artery. Root of tongue also get supply from tonsillar and ascending pharyngeal arteries.

VENOUS DRAINAGE: y is by Deep Lingual Vein. y Two venae comitantes accompany the lingual artery and one vena comitantes accompany the hypoglossal nerve. All veins unite at posterior border of hyoglossus to form lingual vein, which ends either in Common Facial Vein or Internal Jugular Vein.

LYMPHATIC DRAINAGE:y Tips drain bilaterally to submental nodes y Anterior 2/3rd drains unilaterally into right and left

Submandibular nodes. y Posterior 1/3rd drains bilaterally to Jugulo omohyoid nodes

. Lymphatics do not accompany the blood vessels. Tip of the tongue presents richest lymph drainage. A

cancer affecting the tip spreads to all cervical lymph nodes of both sides.

NERVE SUPPLYy MOTOR : All intrinsic and extrinsic muscles are

supplied by Hypoglossal nerve, except palatoglossus which is supplied by cranial accesory part of pharyngeal plexus. y SENSORY : y General sensory y Special sensory

General sensory:y Lingual nerve carries the general sensation.

Special sensory:y Chorda tympani carries taste sensation of anterior

2/3rd of tongue(except circumvallate papillae) y Glossopharyngeal nerve carries both general and taste sensation of posterior 1/3rd of tongue(also circumvallate papillae) y Vagus nerve through its Internal Laryngeal branch innervates posterior most part of tongue.

TASTE BUDSy Taste buds are small ovoid or barrel shaped intraepithelial

organs about 80 micron high and 40 micron thick. They extend from basal lamina to the surface of epithelium. Their outer surface is almost covered by a few flat epithelial cells, which surrounds a small opening, the taste pore. A taste bud may have more than one taste pore, it leads into a narrow space lined by supporting cells, between these cells are present 10 to 12 neuroepithelial cells,the receptor of taste stimuli. y Rich plexus of nerves is found below the taste buds.

y TASTE BUDS y Taste buds are numerous on the inner wall of trough

y y y y y

surrounding the vallate papillae, in the folds of foliate papillae,on the posterior surface of fungiform papillae, at the tip and lateral borders of tongue. CLASSICAL VIEW: Bitter taste : Vallate papillae Sour taste : Folliate papillae Sweet taste : Fungiform papillae at tip of tongue. Salty taste : Fungiform papillae at borders of tongue.

y RECENT VIEW : y According to recent concepts, it is stated that taste can

not be broken into four primary components, i.e. sweet, salt, sour and bitter. But each taste sensation is consisting of range of stimuli that form a spectrum of sensations making up all taste senses and this all is precieved by receptor cells in taste bud which is supplied by nerve fibres.

ROLE IN MASTICATION AND DEGLUTITIONy During mastication food after being adequately mixed

with saliva and chewed ,is converted into bolus and is placed on tongue in its central depression, series of muscular waves travelling posteriorly along the tongue,passes the food over epiglottis into the oesophagus.

DEVELOPMENTAL ANOMALIES AND PATHOLOGIESy Microglossia y Macroglossia y Ankyloglossia y Bifid tongue y Fissured tongue y Median rhomboid glossitis y Geographic tongue

Micr gl ssiy This is due to the failure of lingual swellings of the

first arch to develop, the tongue which is present in the posterior most part develops from the copula ie the hypobranchial eminence of third arch only.

MICROGLOSSIA

macroglossiatoo large tongue seen in Downs syndrome & Beckwith-Wiedemann syndrome

ANKYLOGLOSSIAy The apical part of the tongue may be anchored to the

floor of the mouth by an overdeveloped frenulum. This condition is called ankyloglossia or tongue-tie. It interferes with speech. Occasionally, the tongue may be adherent, to the palate (ankyloglossia superior).

ANKYLOGLOSSIA

Bifid tonguey The tongue may

be bifid because of non-fusion of the two lingual swellings.

Fiss r

tong

/Scrotal tong

:

y seen as grooves that vary in depth & are noted along

lateral & dorsal aspects of the tongue seen in Down syndrome & Melkersson-Rosenthal syndrome

M

ian Rhomboi Glossitis:

y Presents in the posterior midline of the dorsum of the

tongue ,just anterior to the V-shaped grouping of the circumvalate papilla. This is due to failure of fusion of lingual swellings with tuberculum impar.

GEOGRAPHIC TONGUEy Benign migratory glossitis is a psoriasiform mucositis of

the dorsum of the tongue .its dominant characterstics is a constantly changing pattern of serpiginious white lines surrounding the area of smooth,depappilated mucosa ,with the depappilated areas have reminded others of continental outlines on a globe ,hence the popular term geographic tongue is used

GEOGRAPHIC TONGUE

AGE CHANGESy There is tendency of taste buds to dimnish in

number in old age. Bald tongue, one in which filliform papillae are atrophic is not an uncommon finding in elderly people. Atrophy of lingual papillae may occur in patient with iron deficiency or vitamin b12 def., but in many cases no satisfactory explanation can be given for the presence of smooth tongue.

ORAL MANIFESTATION OF IRON DEFICIENCY AND PERNICIOUS ANAEMIAy The dimming of taste results from degeneration

of taste buds and reduction in their number. Sense of taste for salty and sweet food disappears first. Bitter taste receptors persist much longer. As age and xerostomia progress in senescent person, the tongue sheds its epithelial coats and become smooth(bald) and atrophic(shriveled).

XEROSTOMIAy Dry mouth, also called xerostomia (ZEER-oh-STOH-

mee-ah), is the condition of not having enough saliva, or spit, to keep the mouth wet. Dry mouth can happen to anyone occasionally for example, when nervous or stressed. However, when dry mouth persists, it can make chewing, eating, swallowing and even talking difficult. Dry mouth also increases the risk for tooth decay because saliva helps keep harmful germs that cause cavities and other oral infections in check

Prosthodontic considerations

APPLIED ANATOMYy CLINICAL EXAMINATION y CHANGES ASSOCIATED WITH PARTAIL AND y y y y y

COMPLETE EDENTULISM AGE CHANGES CLASSIFICATION OF TONGUE TONGUE AND STABILITY OF COMPLETE DENTURES NEUTRAL ZONE TONGUE PROSTHESIS

EXAMINATION OF TONGUEINSPECTION & EXAMINATION:y Inspection begins with dorsum of tongue(while it is at rest) for any swelling, ulcer, coating or variation in size, colour and texture. Observing the margins of tongue is next step, also along side other points to be noted is distribution of filiform and fungiform papillae, crenations and fasciculations, depapilated areas, fissures, ulcers, and keratotic areas. y Note the frenal attachment and any deviations as the patient pushes out the tongue and attempts to move it right and left.

Inspection can be done as under:y Wrap a piece of gauze (4*4cm) around the tip of the

protruding tongue to steady it and press warm mirror against uvula to observe the base of tongue and vallate papillae; check for any ulcer or significant swelling. Holding the tongue with gauze, gently guide the tongue to one side and retract the cheek of opposite side to observe foliate papillae and entire lateral border of tongue for ulcers, keratotic areas, red patches and then have the patient touch the tip of tongue to the palate,

y so as to display the ventral surface of tongue and also

floor of mouth; note if any variation like varicosites, tight frenal attachment, stones in wharthon s duct, ulcer, swelling and white patches. Gently palpate muscles of tongue for nodules or tumour like growths by extending the finger onto the base of tongue and pressing forward. Also take into consideration presence of tongue thrust and swallowing pattern along with movements and muscular coordinations

CHANGES ASSOCIATED WITH PARTIAL & COMPLETE EDENTULISMy Tongue size and position at times is the most crucial

and unavoidable dictating factor in fabrication of prostheses.y If patient has been without teeth or prostheses for a

long time or has worn maxillary denture against lower anterior teeth only, then the tongue can become enlarged and powerful causing instability of dentures.

CLASSIFICATION OF TONGUEAccording to House classification: y Class 1: Normal in size, development and function. Sufficient teeth are present to maintain normal form and function. y Class2: Teeth have been absent long enough to permit a change in the form and function of the tongue. y Class3: Excessively large tongue. All teeth have been absent for an extended period of time, allowing for abnormal development of the size of tongue. Inefficient dentures sometimes can lead to the development of class3 tongue

According to wright s classification: y Class1 : The tongue lies in the floor of mouth with tip forward and slightly below the incisal edges of the mandibular anterior teeth y Class2 : The tongue is flattened and broadened, but the tip is in normal position. y C lass3 : The tongue is retracted and depressed into the floor of mouth with the tip curled upwards, downwards or assimilated into body of tongue.

ROLE OF TONGUE DURING FABRICATION AND SUCCESS OF PROSTHESES

y A small tongue can facilitate impression making but may

jeopardise the lingual seal.y A relatively large tongue may act as hinderance while

making impression, but a good lingual seal is always expected out of ity Whereas a very large tongue prevents tray placement while

making impression or causes difficulty in the same and latter on contributes to the instability of the denture.

y Also tongue movements and muscular coordination are

important for a number of reasons. As proper tongue movements are necessary for border molding impressions. Tongue movements and muscular coordination are necessary in controlling the denture in mouth during normal physiological activities such as speech, deglutition, mastication.y Tongue position is important to the prognosis of

mandibular denture.

INFLUENCE AND ACTION OF FLOOR OF THE MOUTH

INFLUENCE AND ACTION OF FLOOR OF THE MOUTH

y Suprahyoid muscles are the digastric, stylohyoid, mylohyoid and the geniohyoid. y The mylohyoid and geniohyoid may influence the borders of the mandibular denture. y The right and left mylohyoid muscles together form the floor of the mouth.

The mylohyoid muscle Origin: From the whole length of mylohyoid line. Insertion: Posterior fibers to the body of the hyoid bone. Middle and anterior fibers to the median raphae that unites the right and left muscles. Nerve supply: mylohyoid nerve. Actions : Elevates the floor of the mouth during swallowing. Depress the mandible and elevate the hyoid bone.

The mylohyoid muscley The muscle lies deep to the sublingual gland in the region of 2 premolar. The posterior part of the muscle in the molar region affects the lingual impression border in swallowing and moving tongue. y If the denture flange is extended below and under the mylohyoid line, it will impinge on mylohyoid muscle and the action of the muscle can unseat the denture.

the distal-lingual extension should extend over the retro molar pad and about 3 mm below the mylohyoid ridge.

The thick lingual flange can dislodge the denture.

The mylohyoid muscley If the flange stops above the ridge, vertical forces will still cause soreness, and the seal will be broken easily.

y The denture flange can extend below, but not under the mylohyoid line.

y In cases of extensive bone loss, mylohyoid can be surgically detached and reattached inferiorly.

RETROMYLOHYOID FOSSAy This is an area posterior to mylohyoid muscles. y Bounded by retromylohyoid curtain. y Posterolateral- overlies the superior constrictor muscle. y Posteromedial- covers the palatoglossal muscle. y Inferior- overlies submandibular gland.

RETROMYLOHYOID FOSSAy The denture border should extend posteriorly to

contact retromylohyoid curtain when the tip of the tongue is placed against the front part of upper residual ridge.

RETROMYLOHYOID FOSSAProtrusion of the tongue causes the retromylohyoid curtain to move forward.

Alveololingual sulcusy The space between the residual ridge and the tongue which extends from lingual frenum to the retromylohyoid curtain.

y Can be considered in 3 regions.

y 1. Anterior region : This extends from lingual frenum to where the mylohyoid curves down below the level of the sulcus. This depression is called premylohyoid fossa.

Anterior regiony This results from the concavity of the mandible joining the convexity of the mylohyiod ridge.

y The lingual border of the impression in this anterior region should extend down to make definite contact with the mucous membrane floor of the mouth when the tip of the tongue touches the upper incisors

The middle regiony Extends from the premylohyoid fossa to the distal end of

mylohyoid ridge curving medially from body of the mandible. The curvature is caused by prominence of mylohyoid ridge.

y When the mylohyoid muscle and the tongue are relaxed, the

muscle drapes back under the mylohyoid ridge. If the impression is made under these conditions,the muscle will be trapped under the ridge when the tongue is placed against upper incisors

The middle regiony A slope of the lingual flange towards the tongue in the molar region allows the mylohyoid muscle to contract and raise the floor of the mouth without displacing the denture.

The posterior regiony This part is the retromylohyoid space or fossa. y It extends from the end of the mylohyoid ridge to the retromylohyoid curtain ( glossopalatine and superior constrictor muscles). y The denture border should extend posteriorly to contact the retromylohyoid curtain( the posterior limit of alveololingual sulcus) when the tip of the tongue is placed against the front part of upper residual ridge.

The posterior regiony The distal end of the lingual flange turns buccally to fill the retromylohyoid fossa.

y When the lingual flange is developed in this manner the border has a typical s shaped curve

y If the floor is too low ,so the dentist tends to over extend the denture flange, which leads to loss of retention because the denture flange impinges on the tissue & gets dislodged during the activation of the floor of the mouth.

y The mandibular denture should be stable enough to resist a gentle push on the mandibular incisors by the tongue.

y Tongue position has an important bearing on impression making and subsequent ability of the patient to manage with the mandibular denture.

y All procedures leading to completing a lower impression should be done with tongue in its normal position.

OCCLUSAL PLANEy According to Fenn to obtain maximum stability of

lower denture, the occlusal plane of the lower teeth should be very slightly below the bulk of tongue, so that tongue performs the majority of its movements above the denture and thus keep the denture down.

y According to winkler at the time of try in tongue is a

guide evaluating the height of occlusal plane. At rest after swallowing with its tip touching the lingual surface of lower anterior teeth, tongue assumes a position in which its lateral border (at the junction of keratinised and non keratinised mucosa) is at the level of lingual contour of lower natural posterior teeth, so same should be simulated while fabricating prostheses.

OCCLUSAL PLANE:y If too high------ then teeth can bite papillae during

function. And tongue touches upper incisors and hence leads to upper and anterior emission during speech.y If too low-------then tongue can overlap the lower

teeth and can cause tongue bitting and during speech s will be pronounced as sh.

NEUTRAL ZONEy Neutral zone is the area in the mouth where outward

pressing functional forces of tongue are neutralized by forces of lips, cheeks pressing inwards. These forces are developed during functions, chewing, speaking ,swallowing. y The soft tissue that form internal and external boundaries of denture base influences the denture stability. It is to understand and determine the peripheral borders, tooth position and external contours of denture.

y According to Dr. Wilfred fish (1948), Denture has

three surfaces, each surface is playing independent and important role in fit and stability and comfort of denture, the three surfaces being:y TISSUE SURFACE y POLISHED SURFACE y OCCLUSAL SURFACE

y For a muscular forces to be of a stabilising nature, Dr.

Fisch (1948) described cross section of a stable denture in molar area to be in triangular in shape, with tooth being at apex and denture periphery as the base.

y If the inclined planes of the external surface of denture are

properly fashioned and forces are of equal magnitude, then resultant force will be in seating direction.y If denture are triangular but not properly located within

the neutral zone, then the lateral force will be unequal, hence compromising the stability of the denture.

EFFECT OF LINGUAL FRENUMy Lingual frenum: It is a fibrous band of tissue that overlies the centre of genioglossus muscle, usually it is narrow single band of tissue, but may be broad and exist as two or more frenums. y In case of hypertrophic frenum: lingual frenectomy is done. y In case ankyloglossia exist with a heavy alveolar attachment, then detachment of fibres may be necessary to ensure clearance. In patients of lingual frenectomy, the denture should be made before the surgery, to prevent relapse, as this denture acts as a stent.

y Careful clearance is needed in this area of impression,

as well as in the finished denture, as lingual frenum is attached to tongue and inadequate clearance may result in LOSS OF SEAL and a loose UNSTABLE denture y Frenum is basically a fibrous connective tissue and do not contract or expand like muscles. In some patients lingual frenum may be so short that patient can hardly protrude tongue, in these situations surgical intervention is required(tongue tie). On contrary subsequent scarring after surgical correction may do more harm than good

USE OF TONGUE FOR RECORDING CENTRIC RELATION IN EDENTULOUSy One of the most difficult and important task to

accomplish on complete denture fabrication is retruding the mandible to its centric relation, the tongue can be helpful, however some patients do not have the neuromuscular ability to control the movements. In those patients a rectangular strip of baseplate wax with four circular holes can be adapted and sealed to the midline of palatal surface of the maxillary record base. Using these holes as guide patient can practice untill the desired CR is can be habitually repeated

ROLE OF TONGUE IN SPEECHy Artic lati

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siti a

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c ee s i relati

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t er ral str ct res.

e is ri ci al str ct re res

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asic t a creates c a

ve e ts are c a i ei f r a

tr lle lar

y its attac e extri sic ve e ts. e i tri sic e, s c as elevati

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t a certai exte t y

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r e ressi

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e i tri sic

sc lat re as t e

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iscrete c a a i

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ei

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PROSTHETIC RECONSTRUCTION OF MANDIBULAR TONGUEy A total glossectomy or laryngectomy results in loss of basic vital functions and loss of speech. y In these patients fabrication of a mandibular tongue prosthesis can be done. y Procedure: Diagnostic casts are made and articulated. Mandibular RPD is constructed with a chrome cobalt alloy mesh work which extends to the floor of the mouth.

y Superior portion of the tongue is concave in form to permit food and liquid to pass posteriorly towards the pharynx.

y This tongue prosthesis is effective in improving esthetics and function of the patient.

Tongue prosthesis is constructed from soft medical grade silicon rubber with a flexibletip.

Mesh openings in the alloy meshwork mechanically lock the silicone tongue prosthesis in position.

When teeth comes in contact the tip of the tongue touches the rugae area of the maxilla.

y Superior portion of the tongue is concave in form to permit food and liquid to pass posteriorly towards the pharynx. y This tongue prosthesis is effective in improving esthetics and function of the patient.

SUMMARY AND CONCLUSIONy Knowledge of anatomy, physiology and functions of tongue is

an essence to understand the complex morphological and functional changes in the tongue with aging or with complete and partial edentulism. y This knowledge will help us to reach optimal prosthetic success, as tongue plays significant and perhaps the dictating role in affecting stability and retention of prostheses. y So we can conclude that a proper diagnose of tongue is must before proceeding and planning any type of dental procedures.

REFRENCESy JOHN J. SHARRY Complete Denture Prosthodontics 3rd

edition, Mc Graw Hill Book Company. y ZARB-BOLENDER Prosthodontics Treatment For Edentulous Patients 12th edition, Elsevier. y BERNARD LEVIN Impressions for Complete Dentures, Quintessence Publishing Company. y SHELDON WINKLER Essentials of Complete Denture Prosthodontics 2nd edition, A.I.T.B.S Publishers

y FENN, LIDDELOW & GIMSON S Clinical Dental y y y y

Prosthetics. Mosby. JOHN BEUMER, Maxiollfacial rehabilitation. Mosby Cunningham s manual of practical anatomy, Oxford. Inderbir Singh ,Textbook of Human Embryology, 6th edition.1996, Macmillan India ltd. Orban s, Oral Histology & Embryology, 10th edition, C.B.S Publishers & Distributors.

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