Occlusal Exam Flashcards
what is the definition of malocclusion
a condition in which there is a deflection from the normal relation of the teeth to other teeth in the same arch and/or to teeth in the oppposing arch
what is angle’s classification based on
the relationship of the MB cusp of the maxillary 1st molar and the buccal groove of the mandibular 1st molar
what is an angles class 1
MB cusp of the max 1st molar bisects buccal groove of the mandibular 1st molar
describe class 1 malocclusion
same as normal occlusion but characterized by crowding, rotations and other positional irregularities
what is an angle’s class 2
-MB cusp of max 1st molar is mesial to mand 1st molars buccal groove
-“overbite”
what is an angles class 3
-MB cusp of max 1st molar is distal to buccal groove of mand 1st molar
- “underbite”
what is overjet
the horizontal overlap of the maxillary central incisors over the mandibular central incisors
what is overjet measured with and what is the normal measurement
-periodontal probe
- usually 2-3 mm
what is overbite
the vertical overlap of the maxillary central incisors over the mandibular central incisors
how is overbite measured and what is the normal number
with a probe vertically,
- 2-3 mm or 20-30% of the mandibular incisors
what is erosive tooth wear classified by
the specific mechanism that is responsible for the wear
what can cause erosive tooth wear
-erosion
-abfraction
-abrasion
-attrition
what is dental wear
part of the normal cycle of the dentition but excessive wear and tooth loss leads to a variety of changes within the oral cavity
what is the etiology of dental wear
multifactorial and complex relationships between the 3 types of wear: attrition, erosion and abrasion
what is the evidence of occlusal wear/trauma
-wear facets
-broken restorations
-chipped teeth
what is the evidence of bruxism
-bony ridges- exostosis or tori
- recesssion
-abfraction
- broken teeth and restorations
-excessive attrition
what is abfraction
loss of cervical area due to bruxism
-physical wear along the gingival margin that is not caused by bacterial acid activity
what is attrition
mechanical wear of the incisal or occlusal surfaces as a result of functional or para functional movements of the mandible (tooth to tooth contact)
what does attrition do to bruxism
accelerates it
what can attrition be due to
age
in attrition occlusal surfaces match ___
jaw movements and usually have a similar degree of wear
what type of erosion is abfraction
physical
describe the shape of abfraction
cervical wedge shaped defects
what is abrasion
abnormal tooth surface loss resulting from direct frictional forces between the teeth and external objects or from frictional forces between contacting teeth in the presence of an abrasive medium
what may abrasion occur from
- improper brushing techniques
-habits like holding pipe stem by teeth - vigorous use of toothpicks between adjacent teeth
what does improper brushing techniques causing abrasion look like
seen as a sharp V shaped notch in the gingival 1/3 of the tooth
where can abrasion occur and what causes each
- interproximal: toothpicks
-incisal notching: nails, pipe - cervical: toothbrushing
what is erosion
wear or loss of tooth structure by chemicomechanical action
what causes facial erosion
lemons, chlorine
what causes lingual erosion
bulimia
what are oral signs of bulimia
-raised amalgams
-thermal sensitivity
-thinning, chipping of incisal edges
-anterior open bite
-loss of vertical dimension
