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Flashcards in 8. BAMS Oral Biology Deck (13):

Describe the stages of the feeding sequence:


Stage I transport

Mechanical processing

Stage II transport

Swallowing pharyngeal phase

Movement of food into mouth from external environment accomplished by biting. Lips provide anterior oral seal

Food gathered on tip of tongue and moved to level of posterior teeth (tongue and hyoid bone retract and oropharynx narrows)

Solid foods are broken down and mixed with saliva; moist foods have fluid removed before transport (food chewed with premolars and molars; soft foods squashed against hard palate)

Bolus moved posteriorly by "squeeze-back" mechanism. Chewed foods moved through fauces to pharyngeal surface of tongue. Posterior oral seal holds liquids at pillars of fauces

Involuntary movement pushes bolus through pharynx into oesophagus. Epiglottis seals off larynx, preventing food entering respiratory tracts. Upper oesophageal sphincter relaxes to allow bolus into oesophagus and then contracts to counteract backflow


What 4 ways are reflux prevented

What 4 things contribute to tooth erosion

What is swallowing a process of

What is abfraction

What is abfraction breakdown dependent on

List 6 oral causes of speech and language defects

Upper oesophageal sphincter, lower oesophageal sphincter, soft palate elevation, tongue contact with pillars of fauces and posterior pharyngeal wall

Reflux, vomiting, regurgitation, rumination

Food propulsion, reflux prevention, airway protection (upper/forward movement of larynx, laryngeal inlet closure - epiglottis, vocal cord abduction, aryepiglottic muscles, stop breathing - apnoea)

Stress lesions - wedge-shaped notches caused by flexure and ultimate material fatigue of susceptible teeth at locations away from points of loading (cervical regions)

Magnitude, duration, frequency and location on occlusal forces

Malocclusions, loss of teeth, cleft lip and palate, denture-related, tongue-related (tongue-tied), xerostomia


List 2 types of bone growth

What does Tomes process do

What is an enamel tuft

What is an enamel lamella

What is an enamel spindle

What is and enamel knot

Endochondral ossification, intramembranous ossification

Establishes crystallite organisation

Hypomineralised DEJ regions due to residual matrix protein at prism boundaries

Incomplete maturation of groups of prisms

Odontoblast processes extending into enamel

Where cusps, mammelons and cingulum are formed


Name two types of tertiary dentine and what they are formed from

What is the function of the gag reflex

In which 4 ways is it evoked

Reactionary (mild stimulus - primary odontoblasts) and reparative (intense stimuli - secondary odontoblasts as primary odontoblasts destroyed)

To prevent material entering pharynx

Evoked by mechanical stimulation of fauces, palate, pharynx and posterior tongue


List 7 dentine-pulp responses to injury

Immediate (pain), one min (early inflammation), ten mins (oedema, nociceptor sensation), 100 mins (enzyme activation, nerve growth factors), 1 day (nerve sprouting), 1 week (repair, tertiary dentine formation), variable (complete recovery)


What is dentine hypersensitivity

Short, sharp pain arising from exposed dentine in response to stimuli that isn't any known defect/pathology. Caused by hydrodynamic theory (tooth wear and gingival recession)


For the following muscles, list the origin(s), insertion(s) and function:



Lateral pterygoid

Medial pterygoid

Zygomatic arch; lateral surface and angle of mandible; mandible elevation

Temporalis - floor of temporal fossa; coronoid process and anterior body of ramus; mandible elevation and protrusion

Lateral surface of lateral pterygoid plate; head of condyle and intra-articular disc; mandible protrusion and lateral deviation

Medial surface of lateral pterygoid plate and maxillary tuberosity; medial surface of angle of mandible; mandible elevation and protrusion


Name 4 suprahyoid muscles

Name 4 infrahyoid muscles

Name 3 intrinsic tongue muscles and their function

Name 4 extrinsic tongue muscles and their function

Digastric, geniohyoid, mylohyoid, stylohyoid

Thyrohyoid, sternohyoid, omohyoid, sternothyroid

Vertical, longitudinal, transverse - alter tongue shape

Genioglossus, hypoglossus, palatoglossus, styloglossus - alter tongue position


What is dysphagia

What is dysphasia

What is dysarthria

Swallowing disorder

Language disorder

Difficulty speaking (problems with speech muscles)


What are the 5 stages of tooth development


Initial stage

Cap stage

Bell stage

Late bell stage

Initiation, morphogenesis, cytodifferentiation, matrix secretion, root formation

PEB divides into vestibular lamina and dental lamina

8-10wks iul - enamel organ forms can over papilla

Name; organ becomes 4 cell layers and tooth shape starts to be defined

Crown shape well-defined and enamel and dentine formation begins


What is dentinogenesis

How does it occur

What is dentinogenesis imperfecta

Dentine formation

Dental papilla cells adjacent to IEE differentiate into odontoblasts. Predentine deposited (dental matrix) and later mineralised

Dentine dysplasia that impedes calcification/metabolism of calcium


What does the first pharyngeal arch give rise to

What does the second pharyngeal arch give rise to

What does the third pharyngeal arch give rise to

What do the fourth and sixth pharyngeal arches give rise to

CN V, muscles of mastication

CN VII, muscles of of facial expression


CN X, cricothyroid muscle


What are the stages of amelobalst differentiation

Explain amaelogenesis

What is amelogenesis imperfecta

Describe the genetic involvement of amelogenesis imperfecta

Morhphogenic, histodifferentiation, secretory (initial, Tomes process), maturative (ruffle-ended, smooth), protective

IEE cells differentiate into ameloblasts after dentine formation has begun. Secretory phase involves secretion and synthesis of matrix proteins. Matrix is partially mineralised. Maturative phase - matrix proteins removed and mineral content is increased. Protective phase - ameloblasts regress to form protective layer

Abnormal enamel formation due to malfunction of enamel proteins

MMP20 gene on long arm of chromosome 11, position 22.3