Aetiology of malocclusion 2 Flashcards
what are the 4 types of supernumerary tooth
conical
tuberculate
supplemental
odontome
conical supernumerary tooth
small and peg shaped
don’t tend to prevent eruption but may displace adjacent teeth
usually found near midline and one or two in number
tuberculate supernumerary tooth
barrel shaped teeth that come in pairs and dont erupt
often extracted as can block eruption of teeth around them
supplemental supernumerary tooth
extra tooth of normal morphology
odontome supernumerary tooth
disruptive mass of dentine/ enamel/ pulp
hypodontia
developmental absence of one or more teeth
name 3 reasons why primary teeth may be retained
absent successor
ectopic successor
infra occluded primary molars
delayed dental development
pathology
what causes teeth to become infra occluded
infra-occluded means occlusal surface below that of adjacent teeth
caused by ankylosis
graded on severity - mild, moderate or severe
balancing extraction
done on the same arch on the opposite side to prevent a midline shift
compensating extraction
done on the opposing arch on the same side to maintain occlusal relationships (prevent over eruption)
uppers more prone to overeruption than lowers
macrodontia and effects
teeth larger than average
poor aesthetics, crowding, asymmetry
microdontia and effects
smaller than average teeth
leads to spacing
name 3 examples of abnormal tooth form
peg laterals
fused teeth
accessory cusps
talon cusps
5 options for treating ectopic canines
1 - prevention , early detection
2 - intercept , extract cs and encourage 3s into place
3 - accept - leave ectopic and monitor
4 - exposure - surgical exposure and orthodontic realignment
5 - surgical extraction
name 2 possible reasons for a ectopic central incisor
trauma to a caused tooth germ to be displaced
ankylosed a
transposition of teeth
interchange in position of two teeth
e.g sequence 1, 2, 3 , 5, 4, 6, 7, 8
true transposition of teeth
full tooth switch , crown and root
pseudo transposition of teeth
partial switch
crowns wrong but roots (apices) are in correct position/ roots are crossed
to have a permanent effect on teeth how long would you need to suck your thumb for per day
more than 6 hours
what consequence might a low labial frenum see
midline diastema
what consequence might a habit of tongue thrusting see
anterior open bite
retrognathic
opposite to prognathic
deficient in the anteroposterior plane of growth
think retruded
what is a class II skeletal occlusion most commonly caused by
retrognathic mandible
‘small mandible’
what is the most common cause of a class III jaw relationship
anteroposterior maxillary deficiency
small maxilla
what are the two supernumerary teeth most likely to erupt
conical and supplemental
