ORTHO IO exam Flashcards
what is crowding caused by?
arch length - tooth discrepancy
supernumeraries
retained teeth
ectopic teeth
how do you measure the amount of crowding?
compare size of teeth to jaw using smartwire
or
measure mesial of one tooth to distal of next
what are the levels of crowding?
mild : 0-4mm
moderate : 4-8mm
severe : >8mm
what causes a diastema?
inadequate pressure forcing the centrals together so the fraenal attachment doesnt migrate labially
what is a class I incisor relationship?
lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors
what is a class II div I incisor relationship?
lower incisor edges lie posterior to the cingulum plateau of the upper incisors
upper centrals are proclined and there is incressed overjet
what is a class II div II incisal relationship?
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
what is a class III incisor relationship?
lower incisor edges lie anterior to the cingulum plateau of upper incisors
overjet is reduced or reversed
what is an incisor overjet?
overlap of the teeth in the horizontal dimension
how do you measure overjet?
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.
what is the normal value of incisor overjet?
2-4mm
what is an overbite?
overlap of teeth in a vertical dimension
what is the normal overbite value?
1/3 coverage of the crown of lower incisor
what are ways to describe an overbite?
incomplete
complete
traumatic
what is it called when there is no overbite at all?
open bite
how do you record an overbite?
measure the widest open area
what point of reference is used when measuring centreline of incisors?
facial midline
what teeth do you assess for buccal occlusion?
relationship of the first permanent molars in 3 planes of space
what is a class I molar relationship?
Mesiobuccal cusp of the maxillary first permanent molar occludes with the mesiobuccal groove of the mandibular first permanent molar.
what are units when describing molar relationship?
a cusp is a unit
what terms are used to describe posterior crossbites?
unilateral
bilateral
lingual
buccal
localised
what are causes for open bite?
tongue thrust
thumb sucking
failure of eruption
tipped posterior teeth due to xla
what is centric occlusion?
occlusion pt makes when they fit their teeth together in max intercuspation (ICP)
what is mandibular deviation?
when closing from rest position the mandible displaces to avoid premature contact
why is mouth breathing of interest to the orthodontist?
can lead to a long narrow face, marginal gingivitis, anterior open bite, supraerupted posteriors
why is digit/ finger sucking of interest to an orthodontist?
can lead to proclined upper incisors, retroclined lower incisors, anterior open bite, narrow upper arch
what is recorded in the IO exam firstly?
OH
gingival condition
teeth present
any teeth of poor prognosis
what is recorded for the labial (upper and lower) segments?
inclination to mandibular/ maxillary base
crowding/ spacing
displaced teeth
angulation of canines
other than OH and labial segments, what else is examined? related to incisors
overjet (mm)
overbite; increased or decreased and complete or incomplete
centre lines (check are coincident and correct within face)
what is examined regarding posterior teeth?
buccal segments- crowding/ spacing, displaced teeth
molar and canine relationships
crowding - mild, moderate or severe
