Class 3 Flashcards
Limitations of Angles classification
Only considers A-P plane
Does not include intra-arch problems
Does NOT discriminate between skeletal and dental malocclusions
Need for treatment
Psychosocial
Developmental
Functional
Trauma
Class II mechanics
Elastics
Head gear
Space availability
Extraction maxillary
Class III mechanics
Elastics
Head gear
Space availability
Extraction
Space Available
Mesial of permanent 1st molar to mesial contralateral permanent 1st molar
Space required
Mesiodistal width of all teeth 2nd premolar to contralateral 2nd premolar
Space analysis Assumptions
The AP position of the incisors is correct
The space available will not change because of growth
How to measure mixed dentition
Measurement of teeth on radiographs
Estimation from proportionality tables
Combination of the above 2
Moyers
Measure total width of permanent mandibular incisors use table to predict width of permanent canines and premolars
Tanaka/Johnston
Mandibular 1/2x mandibular incisors+10.5
Maxillary 1/2x mandibular incisors +11
Relation of Max to Mand
ANB= SNA-SNB
SNA Mean
82
More = protrusive
SNB mean
80
more protrusive mandible
ANB Mean
2
More class II
less class III
FH
Portion to orbitale
