Ideal occlusion Flashcards
Angle’s classification refers to…? (2)
Just anterior-posterior relation of 1st perm molars
*does NOT analyze the vertical or transversal
Angle: Class I molar occlusion?
1st U Molar mesiobuccal cusp OCCLUDES 1st L Molar buccal groove
Angle: Class II molar relation?
LOWER 1st molar buccal groove occludes DISTAL to mesiobuccal cusp
(lower jaw is “pushed” back)
Angle: Class III molar relation?
LOWER 1st molar buccal groove occludes MESIAL to mesiobuccal cusp
(lower jaw is “pushed” forward)
Angle: Canine class I?
U canine cusp occludes BETWEEN distal aspect of L canine & mesial aspect of 1st premolar
Angle: Canine class II?
Distal of L canine occludes DISTAL to cusp of U canine
Angle: Canine class III?
Distal of L canine occludes MESIAL to cusp of U canine
Ideal overjet?
2mm
Ideal overbite?
1/3 of lower covered
optimum arch shape?
- oval
- upper wider anterior-posteriorly and trasnversly
Teeth angulation frontally? (2)
- U posterior: buccal
- L posterior: lingual
Functional tooth contacts for lower molars?
Buccal cusp of L contact dentral fossa of U
Functional tooth contacts for upper molars?
Palatine cusps contact central fossa of L
Each tooth occludes with ____
teeth of the opposite arch except for …? (3)
- two
- 3rd molars
- lower incisors
Lower incisors incisal edge contacts…?
palatine aspect of U incisors
Andrew’s 6 keys?
- Molar relationship
- Crown tip (mesio-distal)
- Crown torque (buccal-lingual)
- Rotations
- Tooth tight contacts
- Oclusal plane (Curve of Spee)
Whats andrew’s plane?
Divides dental crowns in two parts: incisal and
gingival portion: EM point
Andrews molar relationship?
U 1st molar DISTAL surface of DISTOBUCCAL cusp occludes with MESIAL surface of MESIOBUCCAL cusp of L SECOND molar
Andrews crown angulation? (2)
gingival long axes of crown more distal than the incisal portion (positive value)
(therefore all teeth are mesially angulated)
Andrew’s crown torque inclination?
- labiolingual / buccolingual inclination
- positive reading: gingival portion of tangent line/crown is LINGUAL to incisal
How do we measure Andrew’s crown torque?
- Agnle formed by a line which is 90 degree to the occlusal plane AND a tangent line to the bracket side (middle of labial/buccal long axis of clinical crow viewed mesially/distally)
Andrew’s rotation?
- teeth should be free of undesirable rotations
- rotated teeth occupy more space than normal = not normal occlusion
Andrew’s tight contacts?
-no spaces
Andrew’s curve of spee?
on nonorthodontic models ranged from flat to slight curves