Definitions Flashcards
Definition class I incisors?
Lower incisor tip occludes at or below cingulum of upper incisors
Definition class II div I incisors?
Lower incisor tip occludes posterior to upper incisor cingulum
Upper centrals normal proclination or retroclined
Definition class II div II incisors?
Lower incisor tip occludes posterior to upper incisor cingulum
Upper centrals retroclined
Definition class III incisors?
Lower incisor tip occludes anterior to upper cingulum
What is definition of class I molars?
Mesiobuccal cusp tip of upper 6 occludes in mid-buccal groove of lower 6
What is definition of class II molars?
Mesiobuccal cusp tip of upper 6 occludes anterior mid-buccal groove of lower 6
What is definition of Class III molars?
Mesiobuccal cusp tip of upper 6 occludes posterior to mid-buccal groove of lower 6
What is definition of 1/2 class II?
Mesiobuccal cusp tip of upper 6 occludes cusp-cusp to mesiobuccal cusp of lower 6
What is definition of 1/2 Class III?
Mesiobuccal cusp tip of upper 6 occludes cusp-cusp with ditto-buccal cusp tip of lower 6
What is Frankfort mandibular plane?
From lower border of orbit to external auditory meatus
What is average Frankfort mandibular plane?
Meets back of head
What is a reduced Frankfort mandibular plane?
Meets behind back of head
Associated with increased overbite
What is an increase Frankfort mandibular plane?
Plane meets in front
Associated w/ reduced OB and AOB
What is overjet?
Distance between upper and lower incisors in horizontal plane
What is the average overjet?
2-4mm
What is overbite?
The vertical overlap of incisors
Can be complete or incomplete
What is average OB?
1/3 upper incsiors overlaps lower incisors
What is increased OB?
> 1/3 upper incisors overlap lower incisors
What is reduced OB?
<1/3 upper incisors overlaps lower incisors - can be edge-edge
What is a lingual cross bite?
Buccal cusp of lower molar/premolar occludes lingual to lingual cusp of upper permolar/molars
What is a buccal cross bite?
Buccal cusp lower molars/premolars occlude buccal to buccal cusp upper molars/premolars
What is anterior cross bite?
1+ upper incisor occludes lingual to lower incisor
What is ROJ?
Reverse overjet
All 4 incisors are in XB
What is SLOB rule?
Same Lingual Opposite Buccal
- Use OPT (horizontal) and USO (65)
- If canine move up USO - moved same direction therefore palatally dispalced
- If canine move down USO - moved opposite direction - buccal displaced