Jaw Relation Flashcards
which JR is the most critical?
Vertical JR
eccentric relation?
any relation other than centric is eccentric
Vertical JR
length of the face as determined by the separation of jaws
what is jaw relation?
JR is the relation of maxillat to mandible
what is camper’s line?
Ala-tragus line (ala of nose and tragus of ear)
Freeway space
- space b/w teeth at rest
-VDR-VDO= freeway space
-2-4mm
in which plane is vertical JR recorded
frontal plane
Why is JR recorded?
to measure extensibility + movements permitted by TMJ w/o harm
types of VJR
1.Vertical dimension at rest
2. ……………………………..at occlusion
Define orientation JR
mandi in most post. position, rotate in sagittal plane around an imaginary transverse axis passing through or near condyles
overbite?
vertical overlap b/w max nd mandi incisors
1mm
Horizontal JR
relation of max nd mand in horizontal plane
increased vertical JR causes
- cheek biting
- increased trauma to denture bearing areas
- increased lower facial height
- stretches facial muscles
Plane of occlusal rim should be ___________________ ( in relation to Maxilla
parallel to plane of maxilla
How do you verify max. rim
using a fox plane
VDO?
length of face when teeth/ occlusion rims are in contact/ mandi in centric relation
what is the difference between kinematic face bow & arbitary face bow
arbitary face bow: with an earpiece
kinematic: has condylar rods
what does orientation jr record?
angulation of max in relation to the base of skull
5?
condylar rods: helps locate TMJ
HJR is in which direction
anteroposterior
how to record orientation jr?
face bow
Types of JR
- orientation
2.vertical - horizontal
types of HJR?
- centric
- eccentric
overjet?
horizontal distance b/w max nd mandi incisiors
1-2mm
what does bite fork represent
mandible
which jr is recorded first?
orientation
which type if relation is learnable, repeatable, nd recordable?
centric relation
3?
locking unit: locks 1 & 2
centric relation?
when mandi is in its most post position, it is called as centric relation
How do you determine the plane of maxilla
by inter-pupillary line + camper’s line
1?
u shaped frame: records the plane of the cranium
2?
bite fork: acts as the mandible
wrong HJR causes?
high points
VDR
length of face when mandi at rest
- ask pt to swallow or wet lips nd mandi places itself in VDR position
angular chelitis is caused by_____ VR?
decreased (angular chelitis is the folding of corner of mouth)
what does the u shaped frame in a facebow function as
represents the plane of cranium
4?
orbital pointer: ant. reference point: infraorbital notch
loss of lip fullness is caused by _______ of VJR
decrease in
parts of a face bow
- u shaped frame
- condylar rods
- bite fork
- orbital pointer
- locking device
Frankfurt horizontal plane
from lower plane of orbit to tragus
angle formed between camper’s line and frankfurt plane?
camper’s line forms a 15-20 degrees angle with frankfurst plane
