ORTHO IO exam

Question 1

what is crowding caused by?

Answer 1

arch length - tooth discrepancy
supernumeraries
retained teeth
ectopic teeth

Question 2

how do you measure the amount of crowding?

Answer 2

compare size of teeth to jaw using smartwire
or
measure mesial of one tooth to distal of next

Question 3

what are the levels of crowding?

Answer 3

mild : 0-4mm
moderate : 4-8mm
severe : >8mm

Question 4

what causes a diastema?

Answer 4

inadequate pressure forcing the centrals together so the fraenal attachment doesnt migrate labially

Question 5

what is a class I incisor relationship?

Answer 5

lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors

Question 6

what is a class II div I incisor relationship?

Answer 6

lower incisor edges lie posterior to the cingulum plateau of the upper incisors
upper centrals are proclined and there is incressed overjet

Question 7

what is a class II div II incisal relationship?

Answer 7

lower incisor edges lie posterior to the cingulum plateau of the upper incisors
upper centrals are retroclined and overjet is minimal or may be increased

Question 8

what is a class III incisor relationship?

Answer 8

lower incisor edges lie anterior to the cingulum plateau of upper incisors
overjet is reduced or reversed

Question 9

what is an incisor overjet?

Answer 9

overlap of the teeth in the horizontal dimension

Question 10

how do you measure overjet?

Answer 10

horizontal overlap measured from the labial surface of the lower incisor to the labial surface of the upper incisor, parallel to the occlusal plane when teeth in occlusion.

Question 11

what is the normal value of incisor overjet?

Answer 11

2-4mm

Question 12

what is an overbite?

Answer 12

overlap of teeth in a vertical dimension

Question 13

what is the normal overbite value?

Answer 13

1/3 coverage of the crown of lower incisor

Question 14

what are ways to describe an overbite?

Answer 14

incomplete
complete
traumatic

Question 15

what is it called when there is no overbite at all?

Answer 15

open bite

Question 16

how do you record an overbite?

Answer 16

measure the widest open area

Question 17

what point of reference is used when measuring centreline of incisors?

Answer 17

facial midline

Question 18

what teeth do you assess for buccal occlusion?

Answer 18

relationship of the first permanent molars in 3 planes of space

Question 19

what is a class I molar relationship?

Answer 19

Mesiobuccal cusp of the maxillary first permanent molar occludes with the mesiobuccal groove of the mandibular first permanent molar.

Question 20

what are units when describing molar relationship?

Answer 20

a cusp is a unit

Question 21

what terms are used to describe posterior crossbites?

Answer 21

unilateral
bilateral
lingual
buccal
localised

Question 22

what are causes for open bite?

Answer 22

tongue thrust
thumb sucking
failure of eruption
tipped posterior teeth due to xla

Question 23

what is centric occlusion?

Answer 23

occlusion pt makes when they fit their teeth together in max intercuspation (ICP)

Question 24

what is mandibular deviation?

Answer 24

when closing from rest position the mandible displaces to avoid premature contact

Question 25

why is mouth breathing of interest to the orthodontist?

Answer 25

can lead to a long narrow face, marginal gingivitis, anterior open bite, supraerupted posteriors

Question 26

why is digit/ finger sucking of interest to an orthodontist?

Answer 26

can lead to proclined upper incisors, retroclined lower incisors, anterior open bite, narrow upper arch