8. Oral Biology Flashcards Preview

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Flashcards in 8. Oral Biology Deck (12):

Types of bone growth (2)

Enamel cross striations due to
What are striae of Retzius
Function of Tomes process
What are Hunter-Schreger bands
What are neonatal lines

Chemical formula of hydroxyapatite

Definition of enamel tuft
Definition of enamel lamella
Definition of enamel spindles
Definition of enamel knot

Endochondral ossification, intramembranous ossification

Daily growth
An effect of transmitted light crossing enamel
Establishes crystalline organisation
Periodic orientation --> banding patterns absent in enamel
Histological representation of striae of Retzius


Hypomineralised DEJ 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


Pulp functions (4)

Types of tertiary dentine (2)

Fibres that contribute to pain sensation

Dentine-pulp responses to injury (7)

Definition of dentine hypersensitivity
Causes of dentine hypersensitivity (2)

Nutrition, dentine growth and repair, defence, neural

Reactionary (mild stimulus, primary odontoblasts), reparative (intense stimulus, secondary odontoblasts - primary odontoblasts destroyed)

A-delta and C-fibres

Immediate (pain), 1 min (early inflammation), 10 mins (oedema), 100 mins (enzyme activation), 1 day (nerve sprouting), 1 week (tertiary dentine formation), variable (complete recovery)

Short, sharp pain arising from exposed dentine in response to stimuli that isn't any known defect/pathology

Tooth wear and gingival recession



Function (3)
Definition of gingivitis
Definition of periodontitis

Types of cementum (2)

Definition of dento-gingival junction

Retains tooth in socket, resists masticatory load, defence barriers

Inflammation of gingiva in response to bacterial plaque on adjacent teeth

Inflammation of periodontium - gingivitis and destruction of alveolar bone and PDL with pocketing

AEFC (primary, cervical 2/3 of root, role in tooth attachment), CIFC (secondary, no role in tooth attachment)

Sulcus between attached and free gingiva


Muscles of mastication

Masseter origin
Masseter attachment
Masseter function

Temporalis origin
Temporalis attachment
Temporalis function

Lateral pterygoid origin
Lateral pterygoid attachment (2)
Lateral pterygoid function

Medial pterygoid origin (2)
Medial pterygoid attachment
Medial pterygoid function

Zygomatic arch
Lateral surface/angle of mandible
Mandible elevation

Floor of temporal fossa
Coronoid process and body of ramus
Mandible elevation and retraction

Lateral surface of lateral pterygoid plate
Inferior head - anterior border of condyle; superior head - intro-articular disc
Mandible protrusion and lateral deviation

Deep head - medial surface of lateral pterygoid plate; superficial head - maxillary tuberosity
Medial surface of angle of mandible
Mandible elevation and protrusion


Other muscles and TMJ

TMJ movements (2)

Types of suprahyoid muscles (3)
Types of infrahyoid (strap) muscles (4)

Types of intrinsic tongue muscles (3)
Function of intrinsic tongue muscles
Types of extrinsic tongue muscles (4)
Function of extrinsic tongue muscles

Types of muscles of facial expression (2)
Function of muscles of facial expression (2)

Rotation and translocation

Digastric, geniohyoid, stylohyoid
Sternohyoid, omrohyoid, thyrohyoid, sternothyroid

Longitudinal, vertical, transverse
Alter shape of tongue (in mouth)

Styloglossus, hypoglossus, genioglossus, styloglossus
Alter tongue shape and position in mouth

Buccinator, orbicularis oris
Help to control bolus and prevent spillage


Gag reflex

How is the gag reflex evoked (3)

SDA function (3)

Causes of Bells palsy (5)

Acts to prevent material entering the pharynx

Evoked by mechanical stimulation of fauces, palate and posterior tongue

Minimum for acceptable masticatory functions, aesthetics and OH maintenance

Otitis media, trauma, infections, diabetes, LA given too distal (into parotid gland)


Feeding sequence

Description of ingestion phase (2)
Description of stage I transport (2)
Description of mechanical processing

Description of squeeze-back mechanism (2)

Definition of swallowing
Function of swallowing sequence (2)
Stages in swallowing sequence (3)

Food into mouth, lips provide anterior oral seal
Moving material from front of mouth to posterior seal, tongue retracts
Breakdown of some solid foods

Forward movement tongue during occlusal and initial opening stages creates a contact between tongue and hard palate. Contact zone moves backwards, squeezing processed food through fauces

Process by which accumulated food bolus is transported through lower pharynx and oesophagus into stomach. Prevents ingested material form entering the lower airway

Airway protection, feeding

Oral/buccal phase, pharyngeal phase, oesophageal phase


Description of swallowing liquids (2)
Description of swallowing solid foods (2)

Description of mid-sequence swallow
Description of end-sequence swallow

Events in swallowing sequence (3)
How is reflux prevented (4)
How is the airway protected (3)

Liquids gathered on tongue (posterior oral seal). Bolus propelled through oropharynx and hypopharynx into oesophagus

Chewed foods accumulate on pharyngeal tongue and oropharynx (no true posterior oral seal). Food propelled through pharynx into oesophagus

Material swallowed from oropharyngeal tongue

Material moved from oral to oropharyngeal tongue to hypopharynx

Food propulsion, reflux prevention, airway protection

Soft palate elevation, tongue contacts fauces and posterior pharyngeal wall, upper oesophageal sphincter, lower oesophageal sphincter

Upper/forward larynx movement, laryngeal inlet closure (epiglottis), vocal cord abduction


Tooth wear

Causes of erosion (4)

Definition of attrition
Definition of abfraction

Reflux, vomiting, regurgitation, rumination

Tooth wear via tooth to tooth contact

Stress lesions (wedge shaped notches) caused by flexure and ultimate material fatigue of susceptible teeth at locations away from points of loading. Dependent on magnitude, duration, frequency and location of occlusal forces


Causes of language/speech disorders (6)

Definition of dysphasia
Definition of dysphagia
Definition of dysarthia

Stages of tooth development (7)

4 cell layers of enamel organ (4)

Malocclusions, loss of teeth, cleft, denture-related, tongue-related, xerostomia

Language disorder
Swallowing problem
Speaking problem

PEB - 6wks iul
Bud stage - 8-10wks iul - enamel organ forms
Cap stage - 11wks iul - enamel organ caps papilla
12wks iul - dental lamina for permanent successor forms
Bell stage - 14wks iul - enamel organ 4 cell layers
16wks iul - first permanent molar germ forms as distal extension of lamina
Late bell stage - 18wks iul - well defined crown shape

Internal enamel epithelium
External enamel epithelium
Stellate reticulum
Stratum intermedium


Process of dentinogenesis (2)

Stages of ameloblast differentiation (7)
Features of secretory phase (2)
Features of maturative phase (2)
Features of protective phase

What is the purpose of the migration of the cervical loop
How is root shape defined
What does HERS induce

Genetics of amelogenesis imperfecta

Dentine matrix laid down (predentine) and mineralised

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

Enamel matrix proteins formed, matrix partially mineralised
Proteins removed and mineral content increased
Ameloblasts regress

To map out the shape of the crown
By apical growth of HERS
Root dentine formation

Autosomal recessive - MMP20 gene on long arm of chromosome 11, position 22.3


Consequences of refractory period (3)

How does saltatory conduction increase the speed of AP conduction (2)

Order nerve fibres are blocked by LA (4)

Effects of adrenaline (2)
Effects of noradrenaline (3)

Limits maximum frequency of firing, ensures unidirectional propagation of APs, prevents cardiac muscle summation

Saltatory conduction - passive currents spread further along axons in myelinated nerves - fewer regeneration steps per unit length, increasing speed of AP conduction

A-delta, C, A-beta, A-alpha

Decrease TPR, increase CO

Increase TPR, CO and MABP (can cause reflex hypotension)