oral function and dental development p253 Flashcards

Question

neurons afferent

Answer 1

sensory carry message to CNS going towards brain or spinal cord

Answer 2

motor carry message to muscle, gland or other effector carry message away from CNS

Answer 3

connecting one neuron to another multiple interneurons in reflexes connect sensory to motor

Answer 4

V IX X XI XII

Answer 5

acts to prevent material entering the pharynx

Answer 6

mechanical stimulation of * fauces * palate * posterior tongue * pharynx

Answer 7

CN V, IX, X, XI, XII visceral nerves of salivary glands

Answer 8

CoCr mesh at post dam region to reduce mucosal coverage reduce the weight of a large connector

Answer 9

* inability to wrinkle brow * drooping of eyelid * inability to close eye * inability to puff cheeks - no muscle tone * drooping of mouth, food stuck in cheek

Answer 10

temporal zygomatic buccal mandibular cervical To Zanzibar By Motor Car

Answer 11

infections (HSV/Cold sores) otitis media (inflammation of middle ear) diabetes trauma toxins temporarilu by infiltration of LA to facial nerve branches * inject to far distally * parotid gland is penetrated * allows diffusion of LA through loose glandular tissue * affects 5 terminal branches of facial nerve

Answer 12

pt has feeling of things being stuck in throat difficulty swallowing often associated with achalsia (faily of parasymp ganglion for oesphageal wall) -\> failure of peristalsis

Answer 13

stroke brain injury multiple sclerosis GORD tumors

Answer 14

mechanoreceptors thermoreceptos nociceptors proprioceptors chemoreceptors

Answer 15

Have a low thresholds, allowing the senses of touch and pressure (0.5mN) Adapt to constant stimulus- they are slow and adapting types TMJ receptors, Muscle receptors, PDL receptors Periodontal Mechanoreceptors * Sensitive 10-100mN * They display directionality \> Can percieve direction of pressure * Used in food texture discrimination * Tooth contacts * functional loading DETECTION OF HIGH SPOTS!\* - can detect down to half the thickness of a human hair \*remember scenario that shows benefits of keeping teeth in rpd for mechanorecptive use \> loss of periodontal mechanoreception precludes to = poorer jaw control = poorer precision of bite force magnitude = poorer perception of direction = rate of occlusal load application

Answer 16

Cold Thermoreceptors * increase firing with a decrease in temperature [Aδ and C fibres] * located at dermal-epidermal junction Hot Thermoreceptors * increase firing with an increase in temperature [C fibres] * located in dermis

Answer 17

Free nerve endings with high thresholds respond to intense stimuli associated with pain * \> Aδ fibres - Noxious mechanical and heat stimuli * \> C fibres - Polymodal Carry receptor proteins responsive to different noxious stimuli

Answer 18

‘Self sense’ Awareness of position and orientation of body parts Types include * Joint receptors * Joint position (mouth open/closed) * joint movement (opening/closing) * useful in controlling movements e.g chewing * Muscle receptors * Golgi Tendon organs * Muscle spindles * Periodontal receptors

Answer 19

e.g. taste buds, olfactory ## Footnote Sense of smell stimulates salivary glands – smelling disorders often affect the sense of taste In Nasopharyngeal infection a loss of smell (Anosmia) may be present Patients have a difficulty discerning between taste and olfaction

Answer 20

ingestion transport mechanical processing food processing

Answer 21

Movement of food from external environment \> mouth Accomplished by biting (anterior teeth) and/or using ‘tools’ (cutlery, cups, etc) Lips provide anterior oral ‘seal’ * Orbicularis Oris * Buccinator

Answer 22

Moving material from the front of the mouth to the level of the posterior teeth * Food is gathered on tongue tip * Tongue retracts pulling the material to the posterior teeth (pull back processs) \> takes 1 second * Hyoid bone retracts \> oropharynx narrows

Answer 23

Some solid foods must be broken down and mixed w/ saliva before they can be swallowed Moist solid foods (e.g fruits) have to have fluid removed before transport and swallowing Food masticated by pre-molars and molar teeth some soft foods are squashed by tongue against hard palate

Answer 24

Involves co-ordination of muscles * Muscles of mastication * Tongue Muscles * Lips and cheeks * Supra hyoid muscles

Answer 25

* controls the bolus * gathers food and rotates to reposition the bolus on the occlusal table * along with cheeks it keeps the bolus on the chewing surfaces * moves the bolus side to side of the mouth * gatehrs bolus for transport during occlusal and inital opening phases of eating the tongue contacts the hard palate * contact point moves progressively backwards squeezing bolus through fauces * SQUEEZE BACK MECHANISM

Answer 26

during occlusal and inital opening phases of eating the tongue contacts the hard palate * contact point moves progressively backwards squeezing bolus through fauces

Answer 27

Solids * accumulate on pharyngeal tongue until swallowing (with the mouth being continues with the oropharynx) Liquids * posterior oral seal acheived during ingestion i.e because liquids are swallowed from the mouth

Answer 28

Jaw joint = Nutcracker hinge Anterior teeth = Near nutcracker handles Posterior teeth = Near hinge if Nut far away from hinge it will require extra force to crack if it cracks at all If the nut is close to the hinge it cracks easily * Hence why first molars have the maximum bite force (due to position and PDL attachment)

Answer 29

Elevation of soft palate Tongue (sides) contacts pillars of fauces Tongue (dorsum) contacts posterior pharyngeal wall Upper oesophageal sphincter * Reflux from oesophagus into pharynx Lower oesophageal sphincter * Reflux from stomach into oesophagus \*If not prevented tooth erosion can result

Answer 30

Upward and forward movement of larynx Closure of laryngeal inlet * aryepiglottic muscles – epiglottis Adduction of vocal folds Stop breathing (apnoea)

Answer 31

specific language disorfer involving damage to particular parts of brain (Broca's area; Wernicke's area)

Answer 32

swallowing problems

Answer 33

difficultuy speaking caused by muscles used in speech

Answer 34

neuromuscular defects Lesions in descending neural pathways ➡ Cranial nerves ➡vocal muscles ➡neuromuscular junctions

Answer 35

Anterior Open Bite * Tongue thrusting * Digit sucking * skeletal origin * Loss of teeth * Cleft Lip * Cleft Palate * Nasal quality * Oral and Nasal cavities not separated Tongue Conditions * Tongue tie * Partial atrophy * Tongue stud Xerostomia * Impeded speech due to inadequate saliva * not solved by simply swallowing then speaking Torus palatinus and Torus Mandibularis * Bony protrusion either on palate or floor of mouth Denture related * Restricted tongue space!! * Denture base too thick? * artificial Teeth not set properly (tilting lingually?) * Wrong occlusal planes \> produces fricative!

Answer 36

partial or complete stoppage of airflow

Answer 37

escape through air constriction missing maxillary incisors can impair fricative soudns, edge should touch vermillion border of lower lip

Answer 38

sudden release after complete stoppage of airflow ('stop' consonants)

Answer 39

air flows through nose

Answer 40

continous airflow shape of mouth varies tongue position main factor

Answer 41

Ectoderm - Enamel Organ Ectomesenchyme (Part of the Neural Crest) forms between the ectoderm and neural tube - * Dental Papilla (Dentine and Pulp) Mesenchyme - Dental Follicle * Cementum * PDL WHOLE STRUCTURE OF - EO, DP and DF = TOOTH GERM

Answer 42

dental papilla (denine and pulp)

Answer 43

dental follicle (cementum and PDL)

Answer 44

initiation morphogenesis cytodifferentiation matrix secretion root formation

Answer 45

Maxillary process formed Stomodaeum formed mandibular process formed * Primary Epithelial band forms at 6w IUL on the stomodeum * This then progresses into the Dental Lamina at 7w IUL it splits into the * Vestibular lamina from which the buccal sulcus develops * Dental lamina from which the enamel organ develops

Answer 46

Bud’ stage * Dental Lamina thickens (A) - Enamel Organ * ectomesenchymal condensation (B) - Dental Papilla ‘Cap’ stage * Enamel organ forms a cap over the papilla * External Enamel Epithelium * Internal Enamel Epithelium * Meet at cervical loop

Answer 47

'Early ‘Bell stage’ * More cell layers differentiate to form a complex enamel organ * IEE * EEE * Stratum intermedium * Stellate reticulum Tooth shape is more defined

Answer 48

Late ‘Bell stage’ * Crown stage well defined * Apposition of enamel and dentine begins Dental Papilla cells adjacent to the IEE differentiate into odontoblasts Odontoblasts lay down dentine matrix which is later mineralised Once dentine formation has begun IEE differentiates into ameloblasts to form enamel ‘Induction’ * Dentinogenesis * Odontoblast differentiation from IEE * Deposition of the Dentine matrix (mainly collagen) * This unmineralised dentine is predentine * Mineralised dentine is by HAP * Amelogenesis * Ameloblast differentiation * Dentine induces IEE cells to differentiate into ameloblasts * They elongate becoming columnar * The nucleus then migrates to the basal end of the cell * Secretory phase * Ameloblasts become secretory cells * They synthesis and secrete enamel matrix proteins (amelogenins) * Matrix is then partially mineralised (30% mineral) * Maturation phase * Most of the matrix proteins are removed * Leaving room to increase the mineral content of enamel * Mature enamel is 95% enamel * Protection phase * Ameloblasts regress to form a protective layer (the reduced enamel epithelium) * Involved in eruption * Formation of epithelial attachment

Answer 49

* Odontoblast differentiation from IEE * Deposition of the Dentine matrix (mainly collagen) * This unmineralised dentine is predentine * Mineralised dentine is by HAP

Answer 50

Ameloblast differentiation * Dentine induces IEE cells to differentiate into ameloblasts * They elongate becoming columnar * The nucleus then migrates to the basal end of the cell Secretory phase * Ameloblasts become secretory cells * They synthesis and secrete enamel matrix proteins (amelogenins) * Matrix is then partially mineralised (30% mineral) Maturation phase * Most of the matrix proteins are removed * Leaving room to increase the mineral content of enamel * Mature enamel is 95% enamel Protection phase * Ameloblasts regress to form a protective layer (the reduced enamel epithelium) * Involved in eruption * Formation of epithelial attachment

Answer 51

Crown formation must be fully completed before root formation Then enamel organ maps out the shape of the crown The EEE and IEE meet at the cervical loop Migration of the cervical loop maps the crown shape The root shape is defined by apical growth of the cervical loop which is now called **hertwig’s epithelial root sheath** * It is a 2 cell type layered structure not 4 like the enamel organ Process 1. Hertwig’s Epithelial root sheath (HERS) induces formation of root dentine 2. Then once the initial layer of root dentine is made HERS breaks up (as there is no enamel in the root) 3. Remnants of HERS persist as the Epithelial cell rests of Malassez 4. Mesenchymal cells from the follicle contact the dentine and differentiate into cementoblasts which form cementum 5. Fibres from the developing PDL are embedded in the cementum ‘Sharpey’s Fibre’s’