GOOD MORNING

TONGUE TONGUE & & PALATE PALATE PALATE

Dr. Dipal Mawani PG Department of Prosthodontics

• Tongue• Introduction• Embryology• Functions• Parts of the tongue• Muscles of the tongue• Papilla• Taste buds & taste discrimination• Blood & nerve supply• Applied anatomy• Prosthodontic considerations• Deglutition

• Palate• Introduction• Hard palate• Soft palate• Muscles of palate• Blood supply• Nerve supply• Passavants ridge• Movement and function of soft palate• Prosthodontic consideration• Conclusion• References

Introduction

• Tongue is a solid conical muscular organ, covered partially by mucous membrane and lies partly in the oral

cavity and partly in the pharynx.

Embryology

• Each pharyngeal arch arises as a mesodermal thickening in the lateral wall of the foregut.

• First (Mandibular) arch• Second (Hyoid) arch• Third arch• Fourth arch• Sixth arch

Functions

• It acts as an organ of taste, and helps in mastication, deglutition and speech.

• In some lower animals (e.g. dog) it is used for thermo-regulation by panting.

• Clinically, it acts as a diagnostic aids in various systemic conditions.

ANATOMY OF TONGUE:FRENULUM

DEEP LINGUAL VEIN

PLICA FIMBRIATA

DORSAL SURFACE:

VENTRAL SURFACE:

pharyngeal (post sulcal) part

• There are underlying lymphoid nodules which are embedded in the submucosa and collectively termed the lingual tonsil.

Muscles of the Tongue

Muscles of the Tongue: A middle fibrous septum divides the tongue into

right and left halves. Each half contains four intrinsic and four extrinsic muscles.

….the former entirely within it and altering its shape.….the latter extending outside the tongue and moving

it bodily.

The intrinsic muscles are superior longitudinal,inferior longitudinal, transverse and vertical.

The extrinsic musculature consistsgenioglossus, hyoglossus, Styloglossuspalatoglossus.

Originate &

insert within

the tongue

Originate outside

the tongue &

insert within

the tongue

EXTRINSIC MUSCLES: Genioglossus

Actions –

i. Genioglossus brings about the forward traction of the tongue to protrude its apex from the mouth.

ii. Acting bilaterally, the two muscles depress the central part of the tongue, making it concave from side to side.

iii. Acting unilaterally, the tongue diverges to the opposite side.

• Hyoglossus:

Action - Hyoglossus depresses the tongue, makes the dorsum convex, helps to retract the protruded tongue .

• Chondroglossus: Sometimes described as a part of hyoglossus, the muscle is

separated from it by some fibres of Genioglossus, which pass to the side of the pharynx.

It ascends to merge into the intrinsic musculature between

the hyoglossus and genioglossus muscles.

• Styloglossus:

Action- pulls tongue upwards & backwards

• Platoglossus:

Actions It Elevates the Root

of the Tongue & approximates the

Palatoglossal arch to its contralateral

fellow, thus shunting off the oral cavity

from the Oropharynx

INTRINSIC MUSCLESuperior longitudinal—Action - shortens tongue - dorsum concave

Inferior longitudinalAction- shortens the tongue - dorsum convex

Transverse muscles— Action— narrow & elongated

Vertical muscle Action- broad & flattened

CIRCUMVALLATE PAPILLAE

Large in sizeLarge in size1-2 mm diameter1-2 mm diameter8-12 in number8-12 in numberSituated immediately in front of Sulcus TerminalisSituated immediately in front of Sulcus TerminalisEach papilla is a cylindrical projection surrounded by a circular Each papilla is a cylindrical projection surrounded by a circular sulcus,sulcus,the walls of which are raised above the surface.the walls of which are raised above the surface.in size1-2 mm diameter8-12 in numberSituated immediately in front of Sulcus Termina

Taste buds:

FFUNGIFORM PAPILLAE:

Numerous near the tip and margins of tongueNumerous near the tip and margins of tongue Smaller than vallate but larger than filiformSmaller than vallate but larger than filiform Each consists of a narrow pedicle and a large rounded Each consists of a narrow pedicle and a large rounded

headhead Distinguished by bright red colorDistinguished by bright red color

FILLIFORM PAPILLAE:

Cover the pre-sulcal area of dorsum of tongueCover the pre-sulcal area of dorsum of tongue Give characteristic velvety appearanceGive characteristic velvety appearance SmallestSmallest Most numerousMost numerous Each is pointed and covered with keratinEach is pointed and covered with keratin Apex is often split into filamentous processesApex is often split into filamentous processes..

FFOLIATE PAPILLA:

Lie bilaterallyLie bilaterallyRed in colorRed in colorLeaf like mucosal ridgesLeaf like mucosal ridgesBear numerous taste budsBear numerous taste buds

MECHANISM OF TASTE PERCEPTION

Adsorption of molecule onto membrane receptor of taste buds

Activation of cascade

Change in membrane polarization

Release of transmitter substance

Afferent fibers' of glossopharyngel nerve

Generation of taste stimuli

Mediated by transducing & gustaducin

VASCULAR SUPPLY

Arterial supply:Arterial supply:

lingual artery which is branch of lingual artery which is branch of external carotid arteryexternal carotid artery

Root of tongue-also by tonsillar & Root of tongue-also by tonsillar & ascending pharyngeal arteryascending pharyngeal artery

Venous drainage:Deep lingual vein—largest & principal route joins with sublingual vein which joins facial vein and internal jugular vein

Lymphatic drainage

TIP— bilaterally— submental nodes

ANTERIOR 2\3rd— unilaterally— submandibular nodes

POSTERIOR 1\3rd— bilaterally— juguloomohyoid nodes.

JUGULO-OMOHYOID NODES known as Lymph nodes of the tongue

INNERVATION OF THE TONGUEMOTOR

SENSORY

TASTE

HISTOLOGY OF TONGUE:

Applied Aspects of tongue too large (macroglossia) seen in Downs syndrome & Beckwith-Wiedemann syndrome

too small (microglossia).

Very rarely the tongue may be absent (aglossia).

• 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.

• Remnants of the thyroglossal duct may form cysts at the base of the tongue.

• The tongue may be bifid because of non-fusion of the two lingual swellings.

• Fissured tongue/Scrotal tongue: seen as grooves that vary in depth & are noted along lateral & dorsal aspects of the tongue seen in Down syndrome & Melkersson-Rosenthal syndrome

• Median Rhomboid Glossitis: 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.

• Benign migratory glossitis: It is a psoriasiform mucositis of the tongue.

• Hairy tongue: A condition of hypertrophy of filiform papillae.

•The under surface of the tongue is a good site (along with the bulbar conjunctiva) for observation of jaundice

•In scarlet fever the atrophy of the lingual mucosa causes the peculiar redness of the strawberry tongue.

•Pernicious anemia & vitamin deficiencies cause characteristic changes such as magenta tongue & beefy red tongue.

Injury to the hypoglossal nerve produces paralysis of the muscles

of the tongue on the side of lesion.

• If the lesion is infranuclear, there is gradual atrophy of the affected half of the tongue (hemiatrophy).Seen typically in motor neuron disease and in syringobulbia.

• Supranuclear lesions of the hypoglossal nerve produce paralysis without wasting. This is best seen in pseudobulbar palsy where the tongue is stiff, small and moves very sluggishly resulting in defective articulation.

• Palpation:

The patient is asked to protrude the tongue onto the gauze. Aided by the gauze the dentist can hold the tongue using a mirror to examine it. Palpation should be done both left to right & right to left & should be done quickly.

The targeted areas are the lateral borders & the region of

vallate papilla

• ‘Tongue function test’ to determine high lingual frenal attachment. Normally the patient should be able to touch the upper lip with the tip of the tongue without dislodging the lower denture and thus the lingual frenum should be relived when found necessary.

• A patient requiring lingual frenectomy, the denture should be made before surgery is performed, where in the denture acts as a stent to prevent future relapse

Prosthodontic aspect of tongue -REST POSITION OF TONGUE

-EFFECTS OF TONGUE IN COMPLETE DENTURE role of impression making in alveolingual sulcus tongue position tongue size tongue space

-EFFECTS OF TONGUE ON SPEECH

-EFFECTS OF TONGUE ON MASTICATION

-ATTENTION DURING DENTURE DESIGN

Rest position of tongue• Dorsum—rest against roof of mouth

• Tip—rest against lingual surface of lower ant teeth

• Lateral borders—against lingual borders of posterior teeth

Role in impression making of alveolingual sulcus

• A) anterior part• It is mainly influenced by the genioglossus muscle, the

lingual frenum and to a lesser extent by the anterior portion of the sublingual gland

• The lingual border of the impression in this region should extend down to make contact with the floor of the mouth, when the tip of the tongue touches the upper lip

b)Middle part

This curvature is due to the prominence of the mylohyoid This curvature is due to the prominence of the mylohyoid ridge and the action of mylohyoid muscleridge and the action of mylohyoid muscle

When the middle of the lingual flange is made to slope toward When the middle of the lingual flange is made to slope toward the tongue, it can extend below the level of the mylohyoid the tongue, it can extend below the level of the mylohyoid ridgeridge

In this way, the tongue rests on top of the flange and aids in In this way, the tongue rests on top of the flange and aids in stabilizing the lower denture on the residual ridgestabilizing the lower denture on the residual ridge

c)Posterior part

Flange can turn laterally toward the ramus to fill the fossa and Flange can turn laterally toward the ramus to fill the fossa and complete the typical s shaped lingual flangecomplete the typical s shaped lingual flange

Floor of the mouth exhibits an active phase and a resting phase Floor of the mouth exhibits an active phase and a resting phase each with a differing lingual vestibular leveleach with a differing lingual vestibular level

Between these 2 levels, the lingual flange of the denture must Between these 2 levels, the lingual flange of the denture must be terminatedbe terminated

Tongue size

small - facilitate impression making but jeopardize lingual seal

large- problem in impression making - denture instability - tongue biting

Tongue space• Artificial teeth must be arranged in neutral zone— where inward pressure of cheeks & lips = outward pressure of tongue If tongue is cramped by denture lateral pressure exerted

instability in denture when tongue moves

Effect of tongue on speech

• Voice principally produced—larynx, while tongue by constantly changing its shape & position of contact with teeth, alveolar process—gives its sound form & its qualities

• Role in speech- Vowels are Produced by the extrinsic muscles of the

tongue Which produce different configuration of the resonating chamber for each vowel.

Consonants are produced by the intrinsic muscles of

the tongue so that the tongue is separated from the teeth, gums or palate by a blast of expired air.

• Dental sounds(th)—– Tip of tongue slightly b\w upper & lower ant

teeth– 3mm space-normal– <3mm-ant teeth too far forward -excessive vertical overlap->6mm-ant teeth too far lingual

• Alveolar sounds(t,d,n,s,z)— tip of tongue - ant most part of palate t d(if teeth far lingual) d t(if teeth far anterior)

Effects of tongue on Mastication

• Tip of tongue- -incise piece of food -if incising not required-shallow concavity at centre-food is placed -transfer backwards along concave surface

• Middle of tongue- -rises & forces food laterally b/w occlusal surface

of teeth - teeth divide food & tongue collect- forms BOLUS -food reaches backwards-tongue & palate passes- pharynx-

oesophagus

Attention during denture design

• Occlusal plane of lower denture- low so that lateral borders rest upon it

• Teeth never inside alveolar ridge • Palate of upper denturethinaccording to strength of

material used• Lingual cusp of lower posterior teeth should not

overhang tongue

Tongue in Geriatric Patients

• There is a tendency for the taste buds to diminish in old aged

• when the person is edentulous for several months without replacement of teeth the

tongue will be hypertrophied.

• Swallowing is initiated reflexly when food or liquid stimulates sensory nerves in the oropharynx.

• In man, 600 swallows are reported to occur in each 24-hour period, but of these, only some 150 relate to feeding.

The remaining swallows, which occur less frequently at night, are unconscious 'empty' swallows that appear to relate primarily to the clearance of saliva from the mouth.

ANATOMY OF SWALLOWING (DEGLUTITION)

ANATOMY OF SWALLOWING (DEGLUTITION)

Swallows have been divided into three phases, usually described as

the first or oral/Buccal- voluntary the second or pharyngeal-Involuntary

the third or oesophageal phases-Involuntary

• ORAL PHASE: The oral phase is voluntary bolus of food is moved from

the oral cavity up to or through the fauces. Transport of the bolus through the mouth is accomplished

by first forming a shallow midline gutter along the tongue to accommodate the bolus, and then by elevating the tongue and the floor of that midline gutter from before backwards.

The gutter is probably formed by the co-contraction of the

styloglossi and the genioglossi.

At this stage a posterior oral seal exists which is associated with elevation of the posterior tongue.

Elevation is accompanied by a relaxation of the posterior oral seal and a forward movement of the posterior tongue which is followed by bilateral contraction of the palatoglossi.

pharyngeal stage:

the tongue raises against the palate, the nasopharynx is closed off, the larynx raises, the epiglottis seals of the larynx & the bolus is passed into the oesophagus

• In this second stage, the three pharyngeal constrictor muscles undergo sequential contraction which is usually interpreted as the driving force which propels the bolus towards the oesophagus

OESOPHAGEAL PHASE:

• OESOPHAGEAL PHASE: The third or oesophageal stage involves the relaxation of cricopharyngeus (the upper oesophageal sphincter) to allow the bolus to enter the oesophagus. Once in the oesophagus, the bolus is propelled by sequential waves of contractions of the oesophageal musculature down to the lower oesophageal sphincter, which opens momentarily to allow the bolus to enter the stomach.

PALATE• pa

INTRODUCTION

• Palate: roof of the oral cavity. • It has two parts – an anterior(bony) hard palate – a posterior(muscular) soft palate

Hard Palate Lies in the roof of the oral cavity Forms the floor of the nasal cavity Formed by:

– Palatine processes of maxillae in front– Horizontal plates of palatine bones behind

• Bounded by alveolar arches

Posteriorly, continuous with soft palate Its undersurface covered by mucoperiosteum Shows transverse folds in the anterior parts

SOFT PALATE

movable muscular fold

suspended from post border of hard palate

Separates nasopharynx from oropharynx

Attached to the posterior border of the hard palate Covered on its upper and lower surfaces by mucous

membrane Composed of:

– Muscle fibers– An aponeurosis– Lymphoid tissue– Glands– Blood vessels– Nerves

Palatine Aponeurosis

Fibrous sheath Attached to posterior border of hard palate Is flattened tendon of tensor velli palatini Splits to enclose musculus uvulae Gives origin & insertion to palatine muscles

Palatine aponeurosis

Near median plane, Near median plane, the aponeurosis splits the aponeurosis splits to enclose the to enclose the musculus uvulaemusculus uvulae..

Tensor veli palatini– Origin: spine of

sphenoid;,scaphoid fossa, auditory tube

– Insertion: forms palatine aponeurosis which is attached to

– (a) Posterior border of hard palate

– (b)Inf surface of palate behind palatine crest

– Action: Tenses soft palate,opens auditory tube

MUSCLES

Spine Spine of of SphenoiSphenoid boned bone

Soft palateSoft palate

UvulaUvula

MusculMusculus us UvulaeUvulae

Palatine Palatine aponeuraponeurosisosis PterygoiPterygoi

d d hamulushamulus

Tensor Tensor veli veli palatinipalatini

Muscles• Levator veli palatini

– Origin:petrous temporal bone, auditory tube.

– Insertion: palatine aponeurosis

– Action: Raises soft palate also dilates auditory tube

Muscles• Musculus

uvulae– Origin:

posterior nasal spine

– Palatine aponeurosis

– Insertion: mucosa of uvula

– Action: Elevates uvula

uvula

Muscles• Palatopharyngeus • 2 fasciculi

– Origin: Ant Fasciculus(Post border of hard palate)

– Post fasciculus(palatine aponeurosis)

– Insertion: posterior border of thyroid cartilage

– Action: Elevates wall of the pharynx

palatopharyngeous

Muscles• Palatoglossus

– Origin: palatine aponeurosis

– Insertion: side of tongue– Action: pulls root of tongue

upward, narrowing oropharyngeal isthmus

Blood supply

Greater palatine branch of the maxillary artery

Ascending palatine, branch of the facial arteryPalatine branch of Ascending pharyngeal, branch of the external carotid artery

VEINS;Pterygoid and tonsillar plexus of veins

Lymphatics Upper deep cervical&retropharyngeal

Sensory Nerve Supply• General Sensory:Mostly by the

maxillary nerve through its branches:– Greater palatine nerve– Lesser palatine nerve

• Special Sensory:For taste sensations: lesser palatine nerves-greater petrosal nerve -geniculate ganglion- facial nerve nucleus of solitary tract.

Secretomotor: greater petrosal nerves.

Motor Nerve Supply

• All the muscles, except tensor veli palatini, are supplied by the:– Pharyngeal plexus

• Tensor veli palatini supplied by the:– Nerve to medial pterygoid, a branch of the

mandibular division of the trigeminal nerve

Passavants Ridge

• Upper fibres of palatopharyngeus• Raises a ridge• Morphology• Best developed in cleft palate

Movements & functions of Soft palate

• Controls 2 gates• Isolates mouth from Oropharynx during chewing• Separates Oropharynx from nasopharynx• Vary degree of closure of pharyngeal isthmus to modify

quality of voice• During coughing and sneezing

Clinical Notes• Cleft palate:

– Unilateral– Bilateral– Median

Pharyngeal

isthmus

• Paralysis of the soft palate– The pharyngeal isthmus can

not be closed during swallowing and speech

– Nasal regurgitation– Nasal twang– Flattening of Palatoglossal

arch

PROSTHODONTIC CONSIDERATIONS

Classification of soft palate:

PALATAL THROAT FORMSPALATAL THROAT FORMS11) CLASS 1

12) CLASS 2

13) CLASS 3

It is the area between the anterior and posterior vibrating line found medially from one tuberosity to other.

Cupid bow appearance.

POST PALATAL SEAL

An imaginary line across the posteriorpart of the palate marking the division between the

movable andimmovable tissues of the soft palate. This can be

identified whenthe movable tissues are functioning

-GPT 8*

* J. Prosthet Dent.2005Jul;94(1):10-92

VIBRATING LINE

Swenson described it as a vibrating area. Silverman describes the anterior and posterior flexion line.

Johnson and Stratton described them as the ah line (posterior flexion line); blow line (anterior flexion line)

VIBRATING LINE

Anterior vibrating lineIs an imaginary line located at the junction of the attached tissue overlying the hard palate and the movable tissue of the immediately adjacent soft palate.

Posterior vibrating lineIt is an imaginary line at the junction of the aponeurosis of the tensor veli palatini muscle and the muscular portion of the soft palate.

VIBRATING LINE

FUNCTION:

To maintain contact with the anterior portion of the soft palate during functional movements of the stomatognathic system.

WHY IS IT NECESSARY:

The distal border is then least advantageous for providing a seal for retention. The labial and buccal denture borders are generally well sealed by the draping of the soft tissues over them, but there is no lip or cheek to drape over the posterior border of a denture

• Conclusion:

Tongue and Deglutition mechanism forms the integral part of the oral cavity.

Better knowledge of the same will help us to render our services in a better way .

Reference:• Gray’s Anatomy-39th Edition• Clinical Anatomy-Richard S.Snell• Grants Atlas of Anatomy• Essentials of Human Anatomy-A.K.Datta• Text Book of Human Anatomy B.D.Chaurasia• Principals of Human Anat & Physio-Gerard• Text Book of Human Histology-I.B.Singh• Text Book of Human Embryology-I.B.Singh• Shafer’s Text Book of oral pathology-5th edt• Prosthodontic related books- Winkler, Bouchers, sharry,

zarb-Bolender, Heartwell,

Thank You