8. BAMS Oral Biology Flashcards
Describe the stages of the feeding sequence:
Ingestion
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:
Masseter
Temporalis
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
Describe:
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 IX
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
