anatomy of articulation ii_oral tract fs(1)

8/13/2019 Anatomy of Articulation II_Oral Tract FS(1)

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Muscles of Facial Expression


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Facial Expression

Facial expression is an integral part of beinghuman The face is highly communicative and this can

augment linguistic communication

Important elements of facial expression aresymmetry, range of motion and diversity

Muscles support these elements

For speech, the lips form the focus of facial

muscle control Extremely mobile and morphable

Central to facial aesthetics

test on ones that shape lower face not upper

face


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on right: muscles that are cut near their origin

left: full force of the muscles

list of muscles to test on:

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same muscles over here

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Orbicularis Oris

Muscle forming bulk of lipsCircumoral circles mouth

No real origin or insertion

Arises in one angle inserts in other

Action: Draws the lips together to seal mouth

the kissing muscle

Keeps food from spewing forward

Another sphincter put to good use

most important muscle for keeping lips together

muscle

people who loose control on this muscle may notbe able to keep food or liquid in their mouth


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Orbicularis Oris

Fibers from other facial muscles insert into OO as theirtermination Some fibers terminate at corner of mouth

Other continue into body of muscle

Allows for highly complex motionsTwo functional subdivisions: Orbicularis oris inferior (Ooi) lower lip

Orbicularis oris superior (Oos) upper lip

Innervation: Motor - CN VII Left and right sides have independent innervation

Occasionally divided into funtional quadrants

soft tissue insertions

dont have that much mass to move

can move upper lip independently from lower

lip

break up into quadrants

under a high degree of voluntary control

quite useful for closing sphincter

and speech


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I-Clicker Question

What type of speech sound does theorbicularis oris produce?

A) Alveolar stop

B) Velar stop

C) Bilabial stop

C


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Smiling and Puffing Muscles

Risorius: courses from fascia close to mandible to

corner of mouth

Lateral course across face Retracts lips at corners (lateral pull)

Smiling muscle

pull the lips apart

does not have bony origin or insertion...both are in soft tissue


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Zygomaticus major arises on zygomatic bone and inserts in

corner of mouth

Elevates angle of mouth and draws itlaterally

Also a smiling muscle

much more of a smiling muscle


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Buccinator: cheek (buccal) muscle Originates from pterygomandibular raphe

Ligament connecting pterygoid to mandible

Inserts horizontally into upper and lower lips

Flattens cheeks, build up pressure

buglers muscle

Helps move food onto molars

Clears food out from buccal cavity

helps build up pressure in your cheeksdoesnt have clear role in speech, but in whistles, clear food out from molars and buccal cavity


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Lip Elevators

These muscles all insert into mid-lateral region ofupper lip

Levator labii superiorus: Originates from lower orbit

Inserts into upper lip where fibers intermix with OOS

Elevates lip and may help to turn it upwards

Levator labii superiorus alaque nasi - along thenose Nasty long name for a small muscle

Has two divisions One muscle inserts into lateral cartilage of nose to dilate nostril

Other muscle inserts into OOS and helps to elevate medialupper lip

various origins but all inserting into body of the lips

(lift the lip superior)

very tiny muscle


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Lip Elevators

Zygomatic minor Arises just in front of zygomatic major and inserts in

lateral upper lip

Assists in raising upper lipLevator anguli oris: arises from canine fossa of

maxilla and inserts in upper and lower lip

corners Draws corners of mouth up and laterally

Due to UL and LL insertions it can assist in

generating medial compression

a bit medial to zygomatic major

keeps mouth tit


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Lip Elevators

Incisivus labii superiorusArises from maxilla near canine teeth

Runs laterally to angle of mouth

Pulls corner of mouth upwards and laterally

wont test us on


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Lip Depressors

Depressor labii inferiorus Arises from oblique line of mandible inserts in

lower lip

Pulls lips down and outDepressor anguli oris

Arises from lateral margin of oblique line

Converges on orbicularis oris and upper lip corner Lowers angle of mouth and assists in generating

lip compression

names correspond to lip elevators...originate from different parts of the

skull


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Lip Depressors

Mentalis: arises from incisive fossa andinsets into skin of chin

Wrinkles chin and puffs lower lip out

The pouting muscleIncisivus labii inferior

Arises from mandible near lower incisors

Inserts into lower angle of mouth Pulls corner of mouth laterally and

downwards

(bottom of jaw(

(lower lip)

not on test


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Lip Depressors

Platysma: large, thin sheet of muscle Sometimes classified with facial muscles

Arises from pectoralis and deltoids

Inserts throughout lower mouth, chin andmandible

Muscle tenses soft fleshy mouth and assists in

mandibular lowering

Draws lower lip downwards and laterally

May assist in compressing lips

has insertions all the way around the face

sometimes neck muscle or facial muscle

assist in opening mouth and lowering the

mandible


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Other Facial Expression Muscles

Orbicularis oculi: sphincter muscle surrounds eye Upper portion- orbital, lower portion-palpebral

Closes and protects eye

Frontalis: wrinkles forehead

Corrugator supercilii wrinkles eyebrow

Depressor supercilii lowers eyebrowNasalis: depresses nasal cartilages and narrows thenares

Procerus: small, unpaired triangular muscle between

eyebrows Draws eyebrows medially and wrinkles skin over nose

Anterior and posterior nasal dilators

NOT ON TEST YOLO


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Growth of the Lips

Generally follow development of the face Small at birth

Specialized for forming an oral seal during feeding throughpresence of papillae

Papillae decrease once nursing period is ended Initial growth period between 0-2 years

Essentially double in width

Second growth period between 10-17 Follows growth during puberty

Lip control for speech generally matures after jawmovements are stabilized Relatively early production of bilabial sounds

important because they have a role in speech

degluttion


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Aging of Face

Skin loses collagen and hence elasticityHence contraction of facial muscleseventually produces ______________

Onset of ______________ could perhapsbe prevented by not using facialexpressions

In some cases, the paucity of facialexpression in PD makes face look younger

wrinkles

wrinkles


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Lip Features

Border between lip mucosa and skin isthe vermillion border

Mucosa of lip much more sensitive than

surrounding skin

Among the most sensitive regions of body

for sensing texture differences Two point discrimination is almost as good as fingertips

Threshold for discrimination also approaches fingertips


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Facial Nerve

Provides motor innervation to all the musclesof facial expression

Arises from dorsal brainstem at junction ofpons and medulla

Enters internal acoustic meatus and runsthrough petrous portion of temporal bone

Forms geniculate ganglion in temporal bone: cell bodies of tongue taste neurons

somatic sensory axons of external ear, ear canal,and external ear drum


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Facial Nerve

Proceeds to facial canal and exits skullJust before exiting, the stapedial nerve andchorda tympani branches off

Stapedial nerve innervates middle ear muscles

Chorda tympani carries taste sensation from theanterior

2/3 of the tongue and innervates salivary glands(submandibular and sublingual)

It runs through middle ear to eventually merge with lingualnerve of CN V (provides general tongue sensation)

Main motor trunk continues in facial canalExits at stylomastoid foramen Branches to stylohyoid and posterior digastric emerge

here


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Facial Nerve

Main motor branch enters parotid glandwhere 5 divisions emerge: Temporal

Frontalis, occipitalis, orbicularis oculi, corrugator

supercilii, procerus Zygomatic: orbicularis oculi

Buccal: Buccinator, orbicularis oris sup., nasalis, levator labii ms,

zygomatics, Mandibular:

Orbicularis oris inf, depressor labii ms, risorius, mentalis

Cervical: platysma

know these division but do not

need to know muscles that are

innervated by them

know this

not this


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Facial Nerve Branchesgood image


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Facial Nerve Complexities

Complex because fibers from othernerves may join up with facial nerve

Some sensory fibers may be traveling with

facial nerve Some sensory fibers are distributed to the

external ear

Some fibers may carry deep pain from face

Other fibers may carry facial proprioception(controversial)


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Facial Motor Innervation

Upper facial muscles receive bilateralmotor innervation

Both sides of brain innervate each side of

face

Lower facial muscles only innervated by

contralateral side of brain


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Bells Palsy Vs. Central Seven

right side of brain controls right and left

muscles

muscles on the right side of face arecontrolled by left side of brain for lower face

for upper these can be controlled by the

right side as well as the left

only unilateral innervation for lower face

case in which nerve in peripherary is interrupted...facial nerve directly interuppted ...person will loose motor control on entire half of face (bells)

lower quadrant is paralyzedentire face paralyzationsensitivity to loud

sounds


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I-Clicker Question

Which nerve carries sensory informationfrom face?

A) Facial

B) Vagus

C) Hypoglossal

D) Trigeminal

D


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I-Clicker Question

Does it take more muscles to smile orfrown?

A) smile

B) frown

C) equal approximately

C

takes more effort


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Types of Sensation

Sensory information includes Fine touch

Crude touch

Proprioception Pain

Temperature

Sensory information also elicits various reflexes

speech dependents on movement

as well as sensory

come from face, toungue, larynz, pharyx, and mucousa

posture, ability of brain to be aware of posture

not important for speech but for life : pain, temperature, & reflex

very important for infants


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Facial Sensation

Compare with limb Sensation Muscle spindles are typically present in

skeletal muscles of the limbs and trunk

Joint sensors within joints Sensors convey position information,

contraction degree and tension information tobrain

Facial muscles do not have these sensorsdespite being skeletal muscles

face needs discriminative

touch sensation so brain

knows how face is shaped


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Facial Sensation

How does brain learn facialproprioception?

In other words, what sensory information

relates to facial position, muscle tension,mouth opening degree

This information is important for learninghow to shape facial structures for speech

sounds


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Facial Sensation

Information is carried by sensory receptors inskin of face and lips

As the facial muscle stretch, compress and/ortense the skin Tiny sensory receptors carry this information to the

brain

Brains job is to sort out these different patterns

Learn information associated with different facialexpressions that convey emotion or shape acousticsounds


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Examples of Skin Sensory Receptors

wont see diagram or exam questions

on this


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Facial Sensation

In normal speaker brain certainlydifferentiates accurately between differentfacial/lip postures

Both visual and auditory information may behelpful in learning

These considerations are important in speechlearning Also important in considering how a baby learns the

social smile Smile requires considerable facial coordination


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Trigeminal Nerve: CN V

Foremost sensory nerve for the face, oralcavity, nasal cavity, and teeth Largest CN and largest CN nucleus in brainstem

Other sensory portions of nerves such as VII, IX & X actuallyterminate in CN V nucleus

Carries touch, proprioception and pain from theseareas

A smaller branch is the motor nerve that mostly

innervates muscles of mastication and tensor velipalatini

carries sensory information from the face:

from scalp, oral track pharynx receives info from


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Course of Sensory Branch of CN V

Emerges from lateral pons

Trigeminal ganglion is located close tobrainstem

3 main branches emerge off ganglia:

Opthalmic, maxillary & mandibular V1, V2 & V3

Basically supplies entire face

Opthalmic division exits skull through superiororbital fissure Supplies upper face and portions of meninges

(considered part of peripheal)

like three fingers on side of faceupper face around the middle

maxilla bonelower face around the jaw


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Trigeminal Divisions

three divisions are going carry

sensation from the face

these two also carry

info from oral tract


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Trigeminal Branchesmore detailed

gives idea how nerve travels through periphery

import

imprt

CN V gives off three branches

V2 gives off sup alv and infra orbit

V3 mandibular gives of inf. alvelor nerve

does not include motor branch of CN V (also

travels with V3 sepeartely)


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Opthalmic Nerve (V1)

Major divisions: Frontal nerve innervates upper scalp,

forehead, medial upper eyelid and upperorbit

Nasociliary nerve carries innervation fromeyelid, nose, nasal cavity, ethmoidal airsinus

Lacrimal nerve also supplies parts ofeyelid, conjunctiva and lacrimal gland

number of braches (WONT TEST ON)

these areas are convered by mucous membrane and these are covered by nerve

receptors

regulates moisture levels

in eye


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Trigeminal Nerve (V2)

Maxillary branch emerges from trigeminalganglia

Exits skull through foramen rotundum butgives off branches to the meninges Zygomatic branch supplies skin over maxilla and

zygomatic bone

Infraorbital branch supplies upper lip, medialcheek and side of nose

Superior alveolar branch carries sensation fromthe upper teeth and gums

Palatine nerves supply the hard and soft palate

KNOW

learning facial postures


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Trigeminal V3

Motor division supplies tensor velipalatini, tensor tympani, lateral pterygoid,

masseter, temporalis, anterior belly of

digastric, mylohyoid

Note: Remember to divide sensation of

tongue into anterior and posterior

divisions

Arises during embryology

medial pterygoid


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Role in Speech?

Orofacial or circumoral articulators contribute

to:

Shaping the sound output of vowels

______________ of vocal tract

______________ of oral opening

______________ of oral opening

Also

A ______________ of consonant sounds

Active in ____________ of overlapping sounds

facial and jaw muscles need to work together ; facial shape the mouth and jaw opens CN V & CN VII working together

(ahhhh vs eeee)

(singing vs speaking)

O vs EEE

duration

roundness

degree

extension

LENGTH

duration

constriction

coarticulation


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Role of facial muscles in Speech?

Which sounds?Which muscles are active in forming

labial consonants?

Are the upper lip and lower lip separatearticulators?

Do jaw and lower lip have distinctfunctions in speech?

by facial muscles

poss questions for exam

think of sounds like BUH vs FUH ..upper and lower lip in one case are coordinated but other

case only lower lip is activated


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Jaw Anatomy


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Jaw Anatomy

Jaw function for speech and masticationinvolves moving the mandible aroundJaw can be elevated, depressed, protrudedand moved from side to side

This fascinating range of motion is supportedby the horribly complex TMJ and the musclesof mastication

Jaw opening muscles essentially open the

mouth (important for shaping oral cavity) Useful for breathing, inserting food and

propagating acoustic information


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Jaw Anatomy

Jaw closing muscles close mouth whichis useful for crushing food and assistingin production of certain sounds

Closing muscles also participate inrotational grinding of food and movingjaw laterally

One jaw muscle can also elevate larynx how is this accomplished? Effect?


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TMJ

Only true joint of the skull that permitsmovement Most of the other skeletal muscles of the body

move around a joint

Both joints move together Complicated because it allows rotation,

protrusion and lateral motions of the jaw

Joint is formed around the condyl head andanterior mandibular fossa of temporal bone


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TMJ Ligaments

Temporomandibular ligament courses

backwards from zygomatic arch Runs externally or laterally

Inserts on back of condyle neck

Sphenomandibular and stylomandibularligaments are medial ligaments Sphenoid bone to mandible

Styloid to mandible

Temporomandibular ligament is the centralprotective ligament, that restricts movementat the joint and prevents dislocation


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Summary of Jaw Muscle Actions

Raising: masseter, medial pterygoid, temporalis

Lowering: lateral pterygoid, geniohyoid, anterior digastric, mylohyoid,

genioglossus

Protrusion: lateral pterygoid, medial pterygoid

Retraction: temporalis (posterior), mylohyoid, geniohyoid, anterior digastric,

geniohyoidLateral:

lateral pterygoid, temporalis


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Jaw Opening Muscles

SHS 300


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Digastric muscles

Another unusual muscle

Has posterior and anterior bellies united by a

central tendon

Posterior belly courses anteriorly and inferiorly

from mastoid process to hyoid bone body

Anterior belly travels from symphysis backwards

and laterally to hyoid bone body

Small tendinous loop on hyoid stitches muscletogether


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Digastrics

CN V innervates belly and CN VIIinnervates belly

Actions

If hyoid bone is fixed, contraction ofanterior belly opens jaw

Posterior belly draws hyoid backwards


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Lateral Pterygoid

Muscle has two origin points (or heads)

Lateral surface of lateral pterygoid plate and greaterwing of sphenoid

Fibers course backwards to insert into pterygoidfossa Depression on anterior neck of condyle

Action protrudes jaw by pulling condyle down andforward

Alternating contractions of pterygoids allows jaw tomove in grinding motions

Innervation: CN V


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Geniohyoid

Arises from inferior mental spine oninside mandible

Insert onto anterior surface of hyoid

Actions either elevate hyoid or depressjaw

Innervation: CN XII


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Mylohyoid

Arises just below geniohyoid

Forms muscular floor of mouth

Fibers emerge from entire mylohoid line andinsert with contralateral fibers at midline

raphePosterior fibers insert into hyoid

Has minor role in tensing base of mouth and

opening jawCN V


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Jaw Closing Muscles


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Masseter

Most powerful muscle of mastication

Thick, flat quadrilateral muscle

Peripheral muscle covering most of

ramusExternal fibers arise from zygomaticarch and insert into angle and lateral

surface of ramus Forms bulk of muscle


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Masseter

Internal fibers more sparse

Run from zygomatic arch slightly forwards to inserton upper half of ramus

Masseter pulls jaw upward and slightly backwards

This angle optimizes power of muscle allowing

molars to crush foodMasseter may have the most rapid stretch reflex of allmuscles

May have a minimal role in speech unnecessary

closing powerInnervation: CN V


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Temporalis

Broad, thin fan shaped muscle Arises from broad section of temporal bone

Fibers converse during course under zygomaticarch

Insert at anterior border of ramus along coronoidprocess

Anterior and middle fibers are more vertical andelevate mandible

Posterior fibers have an angle and aid in retractingmandible


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Temporalis

Muscle allows more rapid contractionsof jaw, perhaps for snapping

Faster speed may be more useful for

closing mouth during speechInnervation: CN V


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Medial Pterygoid

Arises from pterygoid fossa and medialpterygoid plate (or medial surface oflateral plate)

Recall sphenoid bone

a second slip arises from maxilla andpalatine bone

Fibers course downward, laterally and

backward to insert on medial surface oframus and angle


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Medial Pterygoid

Sometimes called the internal masseter Describes its course and action

Together with masseter, these muscles

cradle the mandible, in the mandibularsling

Innervation: CN V


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dont spend much time on it


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Dentition

SHS 300

dont spend much time on it

know types of teeth, orientation of teeth to idling


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The Teeth

Critical for life and speech articulation

Mastication, aesthetics and articulatory surfacesWhat to know: Types of teeth and basic internal anatomy (Figure 6-

23a & 6-24)

Relationship of teeth to midline (figure 6-25)

Surfaces of teeth and roots of teeth (figure 6-25 & 6-26)

Dental development (pp 313-316) Types of occlusion and malocclusion (pp 316-320)

Innervation of the teeth


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Dentition

Housed in alveoli of maxilla and

mandible

Upper and lower arches

Actually half arches on each side House equal numbers of teeth of the same

type


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could be questions on idenitfying

teeth


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Functions of teeth in mastication

Incisors cutting

Canines ripping

Premolars and molars crushing and

grindingVery effective set of slicers and

mashers for omnivores


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Surfaces of teeth

Midline is the space betweencentral incisors Motion along arch is medial if

moving toward midline

Distal if moving away from midline

Five surfaces Medial surface faces toward

midline

Distal surface faces away frommidline

Buccal surface faces cheeks Lingual surface faces tongue

Occlusal surface is contact surfacebetween upper and lower teeth

medial

distal

ony 4-5 questions on ALL of teeth


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Internal anatomy

Each tooth has a root hidden

in gum line Crown is the visible top third

Juncture of crown and root isneck

Crown is covered with enamel Hard surface overlying the

anatomy of the teeth

Below crown is ivory thatoverlies pulp

Pulp is the nerve ending that

provides sensation andmaintain tooth vitality

Teeth are held in alveolarsocket by thin layer of bonecalled cementum


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Dental development

Humans go through 2 sets of teeth

Infants grow temporary teeth Deciduous or milk teeth

Early buds of teeth present at birth

Begin to erupt through bone and gums at6-9 months of age Interosseous and clinical eruption

Teeth are smaller and fewer than adults(10 teeth per arch in children)

tells you age at which baby teeth are coming in..and contrasts age at which adult teeth come in


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look at in great detail


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Dental developmentGeneral sequence of development Central incisors 6-10 mts

lower before upper

Lateral incisors - 8-10 mts

upper before lower

Canines 10-20 mts

Molars 20-24 mts

Premolars are not present in baby teeth

Review general ages at which permanent teeth grow in


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Innervation of teeth

Teeth obviously have rich sensory innervation

Accurate sensing of pressures and loads against

teeth

Essential for control chewing and other oral forces

Exquisite pain sensation (and thermal sensation?)All innervation originates in trigeminal nerve

(CN V)

Upper teeth supplied by maxillary branch Lower teeth supplied by mandibular branch


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Innervation of teeth

Maxillary branch (V2) splits into different

branches Eventually gives rise to anterior and posterior

superior alveolar nerves Anterior branch innervates incisors and canines

Posterior branch innervates molars and premolars

Mandibular branch (V3) splits into anterior andposterior divisions

Posterior branch gives rise to inferior alveolarnerve that supplies all mandibular dentition


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Occlusal Patterns

Learn occlusal patterns in text

chapter 6....read those over

anatomy of articulation ii_oral tract fs(1)

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