Three dimensions: Orientation relation
 Vertical relation
 Horizontal relation


The facial height that exists between two
arbitrarily selected points, one in the
mandible & the other in the maxilla
(Halperin)
Or
It is the distance between the two selected
points, one on fixed & one on movable
member (GPT 1999)

Established by two things but under different
conditions
- mandibular musculature
- Occlusal stops


Vertical relation of rest.
Vertical relation of occlusion.
Physiologic Rest Position
 It is the vertical and horizontal position the
mandible assumes when the mandibular
musculature is relaxed and the patient is upright
(Davenport)
Or
 It is the mandibular position assumed when the
head is in upright position and the involved
muscles particularly the elevator & depressor
groups are in equilibrium in tonic contraction &
condyles are in a neutral unstrained position (GPT
1999)


The face height that exists when the teeth
are in occlusion (Halperin)
Or
It is the relation of the mandible to maxillae
when occlusal stops are provided by teeth or
occlusal rims (Boucher’s)

The difference between the vertical relation
of occlusion & the vertical relation of rest is
the inter-occlusal space or freeway space.
Constructing or assessing dentures
The clinical procedure is to measure
the rest vertical dimension & the
occlusal vertical dimension & then
calculate the freeway space.
When the mandible is in the rest position &
the teeth are out of contact there is no
strain on the temporomandibular joint
 If new dentures have no freeway space
 If an excessive freeway space


Short term variables
Long term variables
Variables
dimension
Patient supine
Head tilted
-Back
-Forward
Insertion of lower
denture or record block
Stress
Pain
Drugs
Rest vertical
Reduced
Increased
Increased
Increased
Reduced
Reduced
Variable


Prosthetic treatment has an important long
term influence on the rest position.
It has been shown that an average 7 mm
reduction in occlusal vertical dimension.




The position of the mandible
Patient should be calm, cool and relaxed
when the jaw relations are recorded.
Rest position is a position in space not to
be maintained for definite period of time.
Advisable to use several methods and
compare the results
The methods for determining the vertical
relation can be grouped into two categories:

Mechanical Methods

Physiologic Methods
Mechanical methods:
1)
i.
ii.
iii.
Ridge relation:
a) distance of incisive papilla from mandibular incisors
b) parallelism of ridges
Measurement of former dentures
Pre-extraction records



Profile radiographs
Profile photographs
Casts of teeth in occlusion
Facial measurements
2) Physiologic methods
Physiologic rest position
Phonetics & esthetics as guide
Swallowing threshold
Tactile sense
Ridge relation:
Incisive papilla – stable landmark
Paralleling of max. & mandibular ridges plus 5 degree opening.
Clinical crowns of anterior & posterior teeth- same length
Disadvantage: absence of lower anterior teeth – cannot be used
Dentures –measured---correlated ---patient’s face.
Measurements - b/w borders of maxillary & mandibular
denture------Boley gauge.
PRE – EXTRACTION RECORDS:
1) profile radiograph
Disadv: exposure to radiation & time consuming
2)Profile photographs
disadv: angulation of photograph
enlargement
3)casts of teeth articulated in occlusion
Proportional measurement
Lower border of septum of nose – lower border of chin
=
outer canthus of eye – corner of mouth.
CENTRIC OCCLUSAL LINE





Measured before loss of the
remaining natural teeth
Draw centric occlusal line on
lower anterior teeth
at horizontal level of Incisal
edge of opposing upper
anterior teeth.
Sibiliant sounds – s, z, sh, zh,
fish, church, judge
Closest speaking space–
measurement for vertical
dimension
CLOSEST SPEAKING LINE

Methods for determining
physiologic rest position






Swallow & relax
Fatigue
Use of phonetics – M sound
Electromyography
Myomonitor
TENS
missipi
Electromyography
demonstrate their activation potential
visual & audio signs– mandibular position
TENS

Niswonger’s method: (1934)


Two marks


interocclusal distance : 2-4mm
at first premolar region.
Base of nose
Chin
Disadvantages;
Marks on skin – move –difficult
– constant measurement.
 Lack of permanent reference
points.

Tactile methods
1)patient’s tactile sense as a guide
2)Lytle method
3)Boos biometer gnathodynamometer
4)Swallowing threshold





Central bearing device attached to record bases
Central bearing screws – palate of max. denture
base/occlusal rim
Central bearing plate- mand.
Patient participation – very important.
Disadvantage:
Can’t be used in very sensible patients & impaired
neuromuscular patients.
 Patients tended to register a reduced vertical
dimension.
 Relied on pt’ muscular perception.

Swallowing threshold
Theory: swallows – teeth come together –
very light contact
A cone of soft wax on lower denture basecontact upper occlusal rims - Jaw too wide open
Flow of saliva - stimulated
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
Increased risk of traumaclenching of teeth.
Discomfort to patient
Teeth are liable to contact –
causing clicking during speech
Trauma & pain – basal seat areas
of denture
Loss of freeway space- muscular
fatigue
Clicking sound
Elongated appearance of face
Bone resorption
Loss of retension & stability of
dentures
Generalised hyperemia.
1)
2)
3)
4)
5)
6)
7)
8)
Reduced masticatory efficiency
Poor esthetics
Cheek biting/ tongue biting/ lip biting
Denture look
Angular chelitis
Pain in TMJ
Coston’s syndrome
prognathism
Judgement of facial support
Visual observation of space
b/w rims
Observation – sibiliant
words.
Eccentric relation
Centric relation
Protrusive record
Centric relation: -- GPT -8
Centric relation is defined as a
maxillomandibular relationship in which the
condyles articulate with the thinnest avascular
portion of their respective disks with the
complex in the anterior superior position
against the shapes of articular eminences.
This position is independent of tooth contact.
This position is discernible when mandible is
directed superiorly and anteriorly and
restricted to a purely rotatary movement about
a transverse horizontal axis.
Lateral record
Boucher's :
A) static methodsInterocclusal record
Central bearing device
Tracing devices
B)functional methods—chew –in
technique
Needles technique
House technique
Essig technique
Patterson technique
Causes minimal displacement of recording bases
Intraoral interocclusal records- without central
bearing point –using plaster/wax.

Place 3 widely separated lines between the rims in the
centric position

CRITICAL! Check that record base heels/rims do not
touch

Eliminate contact with record bases
Max & Mand Occusion Rims


Two sharp “V”-shaped
notches in the
molar/premolar area of
each sided wax
Depth 1-2 mm
1-2
mm
Too Shallow
- no undercuts



Rehearse making the record without
recording medium
Place occlusion rims intraorally
PVS registration material (Memoreg) over
entire occlusal rim
Too Thick
Good


Want flat record, no
excess on sides of rims
Excess material
recording of the sides of
the rim can cause
deflection when
checking record



Have patient close into record
Ensure smooth arc of closure, no
horizontal deviations
Use index fingers to stabilize lower
record base
Patient opens, relaxes,
and slowly closes
•
•
Gently arc the mandible in
a hinge-like motion
There should be:
•No
translation
•No splinting


Patient slowly closes
Operator uses tactile
senses to ensure the
mandible does not
translate



Patient closes until rims are almost
touching (1 mm separation)
Ask patient to stop as soon as this
position has been reached
Some may not be able to tell when they
contact


Never instruct the patient
to bite firmly
Causes translation or
inaccuracy in the record



Hold position
until set 1-2 min
Remove both
rims together
Separate



Ensure record is
repeatable
Increase the height of
incisal pin 1 mm, invert
articulator
Place wax rims together,
lute with sticky wax - 4
spots






Mixture of ½ plaster + ½ carborundum paste.
mandibular movements-Compensating curves
Disadvantages: time consuming.
Graphic methods:
Intra oral tracing & devices–
Extra oral tracing & devices
Advantages:
Central bearing pins resists biting pressure
Disadvantages:
Not a visible method
Difficult to find true apex
Tracer- definitely seated in a hole
at point of the apex
Always combined with an
intraoral bearing pointdistribute equal pressure on the
bases.
More sharper
Tracing plate- mounted on
mandibular rim
Adv:
Larger- apex-easily demarcated
Visible during tracing
Disadvantage:
Lack of equal pressure on the
ridges




Is the ideal arch to arch relationship and an
optimum functional position of jaws for the
health, comfort and function of the TMJ and
musculature.
Is a hinge position. In CR condyles exhibit
only pure rotation without any translation.
Mandibular movements return or terminate in
centric
It is thus, a reproducible position and therefore
serves as a reliable reference to develop
occlusion in complete dentures.
Prosthodontic treatment foe edentulous patients- zarb-bolender 12th edn.
57



It is a position where upper and lower teeth
are braced against each other during
deglutition.
Serves as a reference position for occlusal
reconstruction in dentulous situations.
It is a posterior border position and the
posterior limit of the envelope of mandibular
motion.
Prosthodontic treatment foe edentulous
patients- zarb-bolender 12th edn.
58
Protrusive relation record
Lateral relation record
Methods for recording eccentric jaw relation
Functional method- needles- house & patterson technique
Graphic method
Tactile / direct check record methods
Christensen’s phenomenon
Due to downward
displacement of the condlyes
along the articular slope.
Protrusive records are made
ofDirect protrusive check
record
Graphic method
Functional procedures

Common methods:
Graphic method
 With check bites of wax
 With positional records of stone/plaster
 Pantography
 Hanau’s formula:
 L = H/8 + 12
L=lateral condylar inclination
H=Horizontal condylar inclination

Method for recording centric relation
Procedure:
position the chair-lie back flat
Strech the neck by pointing the chin up
Fore fingers –both hands-lower border of mandible
Little finger-angle of mandible
Thumbs-into notch above symphysis
Condyle is forced upward & backward
Condyle –uppermost position-jaw hinge freely.
Other methods
1) Celluloid strip method
2) Softened wax method
3) Deep heating/ pooling method
Natural dentition– damage to
periodontal structure,
hypersensitivity, excessive
attrition, hypermobility of teeth.
Pain & dysfunction of
masticatory muscle, headache,
neck& shoulder pain.
Dentures- not in centric
relation— premature contact.
TMJ dysfunction— condyle
press upon peripheral vascular
& innervated part of articular
disc.
Mucosal irritation & soreness.
Spasm of muscle of mastication
Resorption of residual alveolar
ridges.