6 Keys to Normal Occlusion Flashcards
How were the six keys to normal occlusion found?
a study found six routine characteristics on untreated individuals (did not need ortho) were missing on the “ideally” treated cases (people who did need ortho)
What are the six keys of normal occlusion?
- Molar relation
- Crown angulation
- Crown inclination
- Rotations
- Contact points
- Occlusal plane (Curve of Spee)
How should the molars be related?
- The distal marginal ridge of the maxillary first molar occludes on the mesial marginal ridge of the mandibular second molar
- The mesio lingual cusp of the maxillary first molar must occlude on the central fossa of the mandibular first molar
In normal molar relation the _______________ of the maxillary first molar occludes on the mesial marginal ridge of the mandibular second molar
distal marginal ridge
In normal molar relation the _______________ of the maxillary first molar must occlude on the central fossa of the mandibular first molar
mesio lingual cusp
If the maxillary and mandibular molars are in a normal relation… the canines and premolars enjoy a _______________ relationship buccaly and a _________ relationship lingually
cusp embrasure
cusp fossa
In normal crown angulation the gingival portion of the long axis of each tooth was _______ to the incisal portion
distal
The degree of tip of the incisors determines the amount of __________ space they consume
mesiodistal
In crown angulation what does + mean and what does - mean?
+ Reading, distal tip of the crown
- Reading, mesial tip of the crown
In crown inclination what does + mean and what does - mean?
”+” means cervical portion of tooth is lingual to the incisal
”-“ means cervical portion of tooth is buccal to the incisal
The crown inclination of the maxillary posterior teeth is…
continuous
(important)
(on test)
For mandibular teeth, the crown inclincation from canines through the second molars progressively…
increases (on test)
important
For every 4 degrees of lingual root torque there is ___ degree of mesial root tip
1
A rotated molar occupies _____ mesiodistal space
more
A rotated anterior tooth occupies ______ mesiodistal space
less
In the absence of genuine tooth size discrepancies, “ideal” occlusions should have _____ contacts
tight
A ____ occlusal plane should be a treatment goal
flat
Intercuspation of teeth is best when the plane of occlusion is relatively…
flat
