Aetiology of malocclusion 2

Question 1

what are the 4 types of supernumerary tooth

Answer 1

conical
tuberculate
supplemental
odontome

Question 2

conical supernumerary tooth

Answer 2

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

Question 3

tuberculate supernumerary tooth

Answer 3

barrel shaped teeth that come in pairs and dont erupt
often extracted as can block eruption of teeth around them

Question 4

supplemental supernumerary tooth

Answer 4

extra tooth of normal morphology

Question 5

odontome supernumerary tooth

Answer 5

disruptive mass of dentine/ enamel/ pulp

Question 6

hypodontia

Answer 6

developmental absence of one or more teeth

Question 7

name 3 reasons why primary teeth may be retained

Answer 7

absent successor
ectopic successor
infra occluded primary molars
delayed dental development
pathology

Question 8

what causes teeth to become infra occluded

Answer 8

infra-occluded means occlusal surface below that of adjacent teeth
caused by ankylosis
graded on severity - mild, moderate or severe

Question 9

balancing extraction

Answer 9

done on the same arch on the opposite side to prevent a midline shift

Question 10

compensating extraction

Answer 10

done on the opposing arch on the same side to maintain occlusal relationships (prevent over eruption)
uppers more prone to overeruption than lowers

Question 11

macrodontia and effects

Answer 11

teeth larger than average
poor aesthetics, crowding, asymmetry

Question 12

microdontia and effects

Answer 12

smaller than average teeth
leads to spacing

Question 13

name 3 examples of abnormal tooth form

Answer 13

peg laterals
fused teeth
accessory cusps
talon cusps

Question 14

5 options for treating ectopic canines

Answer 14

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

Question 15

name 2 possible reasons for a ectopic central incisor

Answer 15

trauma to a caused tooth germ to be displaced
ankylosed a

Question 16

transposition of teeth

Answer 16

interchange in position of two teeth
e.g sequence 1, 2, 3 , 5, 4, 6, 7, 8

Question 17

true transposition of teeth

Answer 17

full tooth switch , crown and root

Question 18

pseudo transposition of teeth

Answer 18

partial switch
crowns wrong but roots (apices) are in correct position/ roots are crossed

Question 19

to have a permanent effect on teeth how long would you need to suck your thumb for per day

Answer 19

more than 6 hours

Question 20

what consequence might a low labial frenum see

Answer 20

midline diastema

Question 21

what consequence might a habit of tongue thrusting see

Answer 21

anterior open bite

Question 22

retrognathic

Answer 22

opposite to prognathic
deficient in the anteroposterior plane of growth
think retruded

Question 23

what is a class II skeletal occlusion most commonly caused by

Answer 23

retrognathic mandible
‘small mandible’

Question 24

what is the most common cause of a class III jaw relationship

Answer 24

anteroposterior maxillary deficiency
small maxilla

Question 25

what are the two supernumerary teeth most likely to erupt

Answer 25

conical and supplemental