Flashcards in Occlusion Lecture 1 Deck (43):
maximal intercuspal position
Complete intercuspation of opposing teeth, independant of condylar position
"best fit of teeth"
when the dentist says "close all the way"
7 components of the masticatory system
- supporting structures (bone, gums, ligaments)
- the 2 arches
Maxillomandibular relationship with the condyles articulating at the thinnest portion of their disks in the anterior superior position.
- Is independent of tooth contact.
- Rotation strictly about the transverse horizontal axis.
Occlusion of teeth when the mandible is in centric relation. Can be be same as maximal intercuspal position.
retruded contact position
Guided occlusal relationship occurring at the most retruded condylar position.
retruded - as most posterior as possible
distance between xray and mid-saggital plane?
distance between mid-saggital plane and film?
About 15 inches
True or False:
Distance between mid-saggital plane and xray film must be the same between takes otherwise the image is distorted.
True. Image can't be compared to previously taken xrays.
PO || porion
midpoint of upper contour of external auditory meatus
S || sella
midpoint of sella turcica cavity
O || orbitale
lowest point of the inferior margin of the orbit
POG || pogonion
most anterior part of chin
ME || menton
most inferior point on the mandibular symphysis
GN || gnathion
center of the inferior contour of the chin
GO || gonion
center of the inferior contour of the mandibular angle
N || nasion
anterior point of the intersection of the frontal bone and nasal bone
Frankfort Horizontal Plane
PO --> O
porion to orbitale
line bisecting the overlapping cusps of 1st molars and incisors.
cant of the occlusal plane
angle between Frankfort and occlusal plane
9.3 degree angle for perfect class 1 occlusion
How many degrees is the cant of the occlusal plane?
POG --> N
pogonion to nasion
angle between Frankfort and facial plane. It is the degree of or retrusion of the manible
mean angle = 87.7 degrees
How many degrees is the facial angle?
axis orbitale plane
O --> terminal hinge axis
orbitale to terminal hinge axis
terminal hinge axis = where the mandible rotates
GO --> ME
gonion to menton
Frankfort mandibular angle
angle between the frankfort and mandibular planes
mean angle = 21.9 degrees
How many degrees is the frankfort mandibular angle?
Y growth axis
the angle measured between the line formed by S - GN (sella and gnathion) and the frankfort horizontal plane.
- indicates position of chin
- bisects the angle formed by the mandibular and facial planes
inter incisor angle
internal angle the maxillary and mandibular incisors make
- 135 degrees
- occlusal plane bisects this angle dividing it unequally.
maxillary = 60 degrees and mandibular = 75 degrees
mandibular relationship with minimal muscle contraction
occlusal vertical dimmension
distance between 2 points when in occlusion
rest vertical occlusion
distance between 2 points when mandible is in physiologic resting position
Point A: middle of face or nose
Point B: lower face or chin
physiologic rest position
head upright puts the mandible in a position and elevator and depressor muscles are in equilibrium (tonic contraction).
- condyles are neutral
distance between occluding maxillary and mandibular surfaces with the mandible in a set position
interocclusal rest space
difference between rest vertical dimension and occlusal vertical dimension while in occlusion
curve of wilson
follows curve of mandibular molars from one side to the other of the arch
curve of spee
line that follows the occlusal table
occlusion class I
occlusion class II
maxilla sticks out further than class I occlsion
- division 1: central incisors stick out
- division 2: central incisors stick inward
occlusion class II division 1
maxilla sticks out further with the central incisors sticking out
occlusion class II division 2
maxilla sticks out further with the central incisors sticking in
occlusion class III
mandible sticks further out than maxilla.