Occlusion Lecture 1

Question 1

maximal intercuspal position

Answer 1

Complete intercuspation of opposing teeth, independant of condylar position

“best fit of teeth”
when the dentist says “close all the way”

Question 2

7 components of the masticatory system

Answer 2

• dentition
• supporting structures (bone, gums, ligaments)
• the 2 arches
• TMJ
• muscles
• innervation
• vasculature

Question 3

centric relation

Answer 3

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.

Question 4

centric occlusion

Answer 4

Occlusion of teeth when the mandible is in centric relation. Can be be same as maximal intercuspal position.

Question 5

retruded contact position

Answer 5

Guided occlusal relationship occurring at the most retruded condylar position.

retruded - as most posterior as possible

Question 6

distance between xray and mid-saggital plane?

Answer 6

60 inches

Question 7

distance between mid-saggital plane and film?

Answer 7

About 15 inches

Question 8

True or False:

Distance between mid-saggital plane and xray film must be the same between takes otherwise the image is distorted.

Answer 8

True. Image can’t be compared to previously taken xrays.

Question 9

PO || porion

Answer 9

midpoint of upper contour of external auditory meatus

Question 10

S || sella

Answer 10

midpoint of sella turcica cavity

Question 11

O || orbitale

Answer 11

lowest point of the inferior margin of the orbit

Question 12

POG || pogonion

Answer 12

most anterior part of chin

Question 13

ME || menton

Answer 13

most inferior point on the mandibular symphysis

Question 14

GN || gnathion

Answer 14

center of the inferior contour of the chin

Question 15

GO || gonion

Answer 15

center of the inferior contour of the mandibular angle

Question 16

N || nasion

Answer 16

anterior point of the intersection of the frontal bone and nasal bone

Question 17

Frankfort Horizontal Plane

Answer 17

PO –> O

porion to orbitale

Question 18

occlusal plane

Answer 18

line bisecting the overlapping cusps of 1st molars and incisors.

Question 19

cant of the occlusal plane

Answer 19

angle between Frankfort and occlusal plane
9.3 degree angle for perfect class 1 occlusion

Question 20

How many degrees is the cant of the occlusal plane?

Answer 20

9.3 degrees

Question 21

facial plane

Answer 21

POG –> N

pogonion to nasion

Question 22

facial angle

Answer 22

angle between Frankfort and facial plane. It is the degree of or retrusion of the manible

mean angle = 87.7 degrees

Question 23

How many degrees is the facial angle?

Answer 23

87.7 degrees

Question 24

axis orbitale plane

Answer 24

O –> terminal hinge axis
orbitale to terminal hinge axis

terminal hinge axis = where the mandible rotates

Question 25

mandibular plane

Answer 25

GO –> ME

gonion to menton

Question 26

Frankfort mandibular angle

Answer 26

angle between the frankfort and mandibular planes

mean angle = 21.9 degrees

Question 27

How many degrees is the frankfort mandibular angle?

Answer 27

21.9 degrees

Question 28

Y growth axis

Answer 28

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

Question 29

inter incisor angle

Answer 29

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

Question 30

postural position

Answer 30

mandibular relationship with minimal muscle contraction

Question 31

occlusal vertical dimmension

Answer 31

distance between 2 points when in occlusion

Question 32

rest vertical occlusion

Answer 32

distance between 2 points when mandible is in physiologic resting position

Point A: middle of face or nose
Point B: lower face or chin

Question 33

physiologic rest position

Answer 33

head upright puts the mandible in a position and elevator and depressor muscles are in equilibrium (tonic contraction).

• condyles are neutral

Question 34

interocclusal distance

Answer 34

distance between occluding maxillary and mandibular surfaces with the mandible in a set position

Question 35

interocclusal rest space

Answer 35

difference between rest vertical dimension and occlusal vertical dimension while in occlusion

Question 36

curve of wilson

Answer 36

follows curve of mandibular molars from one side to the other of the arch

Question 37

curve of spee

Answer 37

line that follows the occlusal table

Question 38

occlusion class I

Answer 38

normal occlusion

Question 39

occlusion class II

Answer 39

maxilla sticks out further than class I occlsion

• division 1: central incisors stick out
• division 2: central incisors stick inward

Question 40

occlusion class II division 1

Answer 40

maxilla sticks out further with the central incisors sticking out

Question 41

occlusion class II division 2

Answer 41

maxilla sticks out further with the central incisors sticking in

Question 42

occlusion class III

Answer 42

mandible sticks further out than maxilla.

Question 43

neutral position

Answer 43

teeth are in a position where lingual and labial forces are equal. Neutral position can change if forces change