The Registration of Jaw Relations for Completely Edentulous Patient

By
Mohammed M Fouad
Prof of Prosthodontics
Faculty of Dentistry
Mansoura University
THE REGISTRATION OF
JAW RELATIONS

• Jaw relation is defined as “Any relation of
the mandible to the maxilla”
• Three important components (Types):
1. The orientation relations:
o Adjusting of occlusion rims (Prerequisites for facebow transfer).
o Orienting the position of the maxilla or mandible to the skull
(face bow transfer).
2. The vertical relations: VD of rest and VD of occlusion.
3. The horizontal relations: Centric and Eccentric
relations.
Prof Mohammed M Fouad 2

Jaw relations
Orientation Vertical Horizontal
VDR VDO Centric Eccentric
Protrusive Lateral
RT LT

The orientation relations

Adjustment of record blocks
(Prerequisites for face bow transfer)
(To indicate as nearly as possible the dimensions
of the potential denture space)

Record blocks:
Occlusion rims simulate teeth, establish the occlusal plane
when contoured correctly and help in recording vertical
and horizontal relations.
Record bases should be retentive for making an accurate
jaw relation record:
• If slightly loose, denture adhesive can be used
• If pronounced looseness… final impression has to be
remade.

Arbitrary (Laboratory) adjustment of occlusion rims
is followed by actual (clinical) adjustment in patient
mouth.

Arbitrary (Laboratory) adjustment of
occlusion rims:
Maxillary occlusal rim anterior height 22 mm.
Maxillary rim slightly facial to ridge to
compensate for residual ridge resorption to
support upper lip.
Mandibular occlusal rim anterior height 18 mm.
Posteriorly the mandibular occlusal rim is kept
up to 2/3rd of retromolar pad.

Arbitrary adjustment of occlusion rims:

Actual (clinical) adjusting of
occlusion rims:
Factors to be considered are :
1. Lip support & labial fullness.
2. Cheek support & buccal fullness.
3. Overjet between the occlusion rims.
4. Visibility of the occlusion rim.
5. Occlusal plane orientation (level and
parallelism).

1. Lip support & labial fullness:
• The wax in the flange area is
responsible for the labial fullness,
while wax in the incisal edge of the
occlusal rim determines the lip
support.
• The horizontal angle between right
and left side of the upper lip might
be between 90 and 120 degrees.

1. Lip support & labial fullness:
• The center of the curved junction
between the columella of the nose
and the philtrum of the lip should lie
about halfway between the tip of the
nose and the groove behind the ala.
• The sagittal angle between philtrum
and columella (Nasolabial angle)
should be about 90 degrees.

Placing the occlusal rims
more palataly and lingualy
will affect speech &
esthetic and result in
restriction of tongue
movements that displace
the denture.

2. Cheek support & buccal fullness :
The buccal form of occlusal rim should provide
support for the cheeks. More buccally occlusion
rims will result in:
• Displacement (instability) of dentures by buccal
musculature.
• Frequent cheek biting by the teeth arranged
buccally later.

3. Overjet between the occlusion rims :
• The incisal edge of the
maxillary occlusal rim should
be about 2 mm in front of the
incisal edge of the
mandibular occlusal rim.

4. Visibility of the occlusion rims :
• 0.5 – 1.0 mm of the upper
occlusal rim should be below
the level of the upper lip during
rest and up to 2 mm during
speech.
• The lower occlusal rim should
be at the level of the lower lip &
the angle of the mouth.

5. Occlusal plane orientation:
• Occlusal plane represents the mean
of the curvatures of the occlusal
surfaces of teeth.
• The plane of the occlusal rim should
be parallel to the plane of the maxilla.

Importance of occlusal plane orientation:
1. Anteriorly, occlusal plane mainly helps in achieving
esthetic & phonetic.
2. Posteriorly, it forms a milling surface, where tongue &
buccinator muscle are able to position the food bolus
onto it , and hold it there during mastication.
Incorrect occlusal plane would:
• Hamper esthetics, phonetics, & mastication.
• Affect stability of complete denture.
• Result in alveolar bone resorption.

Aids for establishing the occlusal plane:
1. Guide lines: [The lip lines, interpupillary line, ala
tragus line (Camper's line), midline and canine
lines].
2. Commissures of the mouth.
3. Retromolar pad.
4. Tongue.
5. Linea alba.
6. Buccinator groove.
7. Mid way of interarch distance.
8. Parallelism to the mean foundation.
9. Lateral cephalometric radiograph tracing.

Lip Lines (height of the upper lip relative to
the maxillary central incisors.):
 It may be:
• High lip line (the greatest height to
which the upper lip raised during
smiling broadly).
• Low lip line (the lowest position of
the inferior border of the upper lip
during mild smiling or rest).

Interpupillary and Camper's lines:
 Adjusting the parallelism of the maxillary occlusal plane:
• Anteriorly to be parallel with the interpupillary line.
• Posteriorly to be coincide with the Camper's line.
Done using fox plane.

Interpupillary and Camper's lines:

The midline and canine lines

The corners of the mouth and the
retromolar pad:
• Anteriorly the parallelism of the mandibular
occlusal plane should be with the level of the
lower lip & angle of the mouth (corner of the
mouth).
• Posteriorly the level of the occlusal plane should
be at the junction of anterior 2/3rd and posterior
1/3rd of the retromolar pad.

The level of the lower occlusal rim

Linea alba:
Hyperkeratinized zone at the level of occlusal
integration.

Buccinator groove:
Orientation of the
posterior occlusal plane
by using the functional
method (vestibular
impression technique).
Prof Mohammed M Fouad
28

Reference points, lines, planes and angles used to determine the
predicted posterior occlusal plane according to lateral
cephalometric radiograph tracing.
• N= Nasion, S = Anterior nasal spine, O = Orbital, P = the middle of the ear rods of the
cephalostat, P`P =the predicted cephalometric posterior occlusal plane, WWT= wrought wire
fixed to the occlusal surface of tentatively adjusted posterior wax rim before determining the
cephalometric posterior occlusal plane, WWC= Estimated posterior occlusal plane orientation
to be parallel to the cephalometric posterior occlusal plane (P`P), PNS angle = this angle
represent the (X) value in Monteith Formula [Y = 77.3484 – (0.9098 .X )] and OP`P angle = this
angle represent the (Y) value in the Monteith formula.

Orienting or locating the position
of the maxilla in the skull using
an instrument called face bow.

Definition of the orientation relation:
• Orientation relation is the spatial (3D) relation of the
maxilla to some anatomic reference point(s) in the
cranium in three planes (horizontal, sagittal and frontal
planes) determined using an instrument called face bow.
• The maxillary cast in the articulator is the base line from
which all occlusal relationship start. Therefor it should be
positioned in space by identifying three points (two
posterior and one anterior to the maxilla).

• The plane of orientation:
The plane formed by joining two posterior anatomic reference
points and one other selected anterior point. It is a
relationship between the jaws and the axis of movement.

the three planes in cranium (horizontal,
sagittal and frontal planes)

Hinge (transverse) axis: an imaginary line around which
the mandible may rotate within the sagittal plane.
Terminal hinge axis: An imaginary line around which the
mandible may rotate within the sagittal plane in the most
retruded position.
Hinge axis is stable, learnable, recordable, reproducible
and repeatable. Therefore it is used as an important
reference in mounting casts in the articulator, so that the
opening axis of the articulator coincides with the
terminal hinge axis of the patient.

Reproducing the horizontal axis is the most
important steps because accuracy of all the other
relationships depends on a correct starting point.

Face bow

Definition of Face-bow:
• A caliper-like instrument used
to record the spatial
relationship of the maxillary
arch to some anatomic
reference point(s) and then
transfer this relationship to an
articulator; it orients the
maxillary cast in the same
relationship to the opening
axis of the articulator.

Facebow transfer:
 Facebow transfer orients the
maxillary cast in the same
relationship to the opening
axis of the articulator. So it is
the first step in recording the
relationship of the maxillary
arch to the condylar paths on
the articulator.

The importance of recording orientation relation:
• The anatomy and position of the maxilla in
the skull and its relationship to the TMJ
vary from persons to persons.
• As the patient’s jaw opens and closes, the
posterior border of its movement (at least
in the earliest phases) is in the form of arc
in a circle (its radius is not constant for all
patients) in the sagittal plane around an
imaginary transverse axis (the opening
and closing axis) passing through or near
the condyles.

So,
• The relation of the maxilla to this axis has to be
determined for each person.
• For an accurate reproduction of mandibular movements,
the axes of those arcs should coincide between
patients and articulators and the relation of maxillary
cast to the axis of rotation on the articulator must be the
same relation that exists between the maxillae and the
terminal hinge axis in the skull of that patient.

• Maxillary cast is mounted on the articulator as
related to the terminal hinge axis and the
mandibular cast related to the maxillary cast by
means of vertical and horizontal relations record.
• This is necessary in order to develop on the
articulator an occlusal scheme that will need
minimum adjustment in the mouth.
Then,

Thus,
• The purpose of the face bow is to:
1. Place the maxillary cast in the proper spatial relationship to the
horizontal plane.
2. Relate the maxillary cast to the opening and closing axis of the
articulator.
3. Face bow is mainly used when the vertical dimension of
occlusion is expected to be altered.
• This allows the practitioner and the dental laboratory technician
to view the maxillary arch as it appears in the patient.

Indications of facebow:
1. For diagnosis & treatment planning.
2. When cusp form teeth are used.
3. When balanced occlusion of CD is desired.
4. When interocclusal check records are used.
5. During remounting of dentures.
6. With single maxillary complete denture.
7. For full mouth rehabilitation.

Is facebow transfer essential in all
CD cases?
• It is not required when:
• Monoplane teeth are used.
• No alterations to occlusal surface
of teeth are done.
• Articulators that do not accept
facebow transfer.

Advantages of facebow:
Reduce errors in occlusion.
More accurate programming of
articulator.
Supports the maxillary cast while
mounting on the articulator.
Assist in correctly locating the incisal
plane.

Basic parts of a facebow:

Classification of face bow:

Arbitrary facebow:
A device used to approximately
relate the maxillary cast to the
condylar elements of an
articulator.
The approximate position of the
transverse horizontal axis is
estimated on the skin of face
before using this device.
It is commonly used with
complete denture.

The "Fascia bow" type face bow:
• This face bow takes its name from the fact that it rests
upon the face. It rests upon the arbitrarily identified
temporomandibular joint, or rather the hinge axis as
identified by touch. This type utilizes approximate points on
the skin over the TMJ region as posterior reference points.
• These points are located by measuring from certain
anatomical landmarks on the face.

Disadvantages of the "Facia bow" type face bow:
• As the condylar rods are placed on the skin
(is movable) there is a tendency for them to
displace,
• It requires an assistant to hold the face bow
in place.
• Generally locate true hinge axis within the
range of 5 mm. So occlusal discrepancies
should be corrected by minor occlusal
adjustments during denture insertion.

Ear piece type face bow:
• This type uses the external auditory meatus as an
arbitrary reference point which is aligned with ear
piece similar to those of a stethoscope.
Advantages:
• Simple in use.
• Don’t require measurements on face.
• As accurate as other face bows.
• It provides an average anatomic dimension between
the external auditory meatus and horizontal axis of
mandible.
Disadvantages:
• Expected error of 0.2 mm that will result in a
considerable inaccuracy if used with an increased
VDO.

Spring bow

EAR PLUGS
ANTERIOR
REFERENCE
POINTER
Slidematic

Procedure of using arbitrary facebow:
• A separate transfer record base is
recommended for transferring maxillary
cast to articulator. If same record base is
used for centric record, face bow transfer
record can be made either before or after
centric record.
• Seat the patient in the comfortable
position ; patients head should be in the
upright position with the head rest
supporting the occiput .
• Posterior reference point is located by
measuring 12 millimeters anterior to the
middle of the tragus of the ear on a line
drawn from the outer canthus of the eye
to the middle of the tragus of the ear.
Mark the points on the skin.

• Contour the maxillary occlusion rim ;
establish the occlusal plane ; place the
guide lines for the arranging of teeth on
the labial section.
• Make an index on the occlusal surface in
the regions of the first molars. Apply a
thin layer of the petroleum to the occlusal
rims
• Reduce the mandibular occlusal rim to
allow adequate interocclusal distance for
the fork & attached wax.
• Condylar rods (or earpieces) is positioned
on the marked posterior reference point.
• Adjust the condyle rods to the face for
centering the bow. The locking nuts are
then secured.

• Soften a sheet of low fusing base
plate wax and roll together in the
shape of a horseshoe. While the
wax is soft , bite fork is embedded
in it.
• Occlusal rim are inserted into
patient mouth.
• Place the prongs of the bite fork
with the attached soft wax between
the occluding surfaces of the
occlusal rim.
• The midline of bite fork should
coincide with the midline of the
maxillary occlusal rim.
• Instruct the patient to close the
jaws until both occlusal rims are
embedded in the soft wax.

• Slide the stem of the fork through the opening in
the clamp of the bow.
• Adjust the condylar rods to the arbitrary axis
points. Adjust the width of the condyle rods
equidistant bilaterally & secure the clamp of the
bow to the stem of the bite fork.
• Slide the condyle rods from the skin. extend the
condyle rods back to the axis points to check
any displacement.
• When the infra orbital notch is used as the
anterior point of reference the pointer should be
placed in the clamp provided for it on the bow.

Kinematic face bow:
A face-bow with adjustable caliper
ends used to locate the transverse
horizontal axis of the mandible.
Indications:
• When it is critical to reproduce the
the exact opening and closing
movement of the mandible to the
articulator.
Disadvantages:
• Extensive chair side.
• Expensive.
• Rarely indicated with routine
articulators.

Procedure of using kinematic facebow in
partially edentulous patient:
 Facebow is attached to the
lower jaw by means of clutch.
 Graph of Grid paper is placed
near temperomandibular joint
region detects the stylus
movement.
 Patient is asked to open and
close the mandible at centric.
 The stylus is adjusted until the
tip rotates instead of arcing.
 This point identified as the
hinge axis is tattooed on the
skin.

Hinge axis location technique using kinematic face
bow in completely edentulous patient:
• Make an accurate impression of a
mandibular basal seat.
• Pour an accurate stone cast.
• Make an accurate record base of
self cure resin.
• Attach the occlusal rim to the
record base.
• A specially designed bite fork to
the rims with the stem parallel to
the sagittal plane.

• Attach this assembly to
the mandible with chin
clamps or chin straps.
• Attach the hinge bow to
the stem & adjust the
styli to the location of the
condyles.
• Guide the patient in
making hinge openings
& closings.

Jaw relations
Protrusive Lateral
RT LT

Vertical relations (Dimensions)

Definition of vertical dimension:
Vertical dimension
refers to the length
of the lower third
of the face.
It is maintained either by
the occlusion of the teeth
or the balanced tonic
contraction of the opening
and closing muscles of
mandibular movements.

Ideal Facial vertical dimensions

The Vertical Jaw Relations are expressed as the
amount of separation of the maxilla & mandible
under specified conditions.
The Vertical Jaw Relations can be
recorded in 2 positions:-
1) The vertical dimension at rest position
2) The vertical dimension at occlusion.
Definition and types of Vertical Jaw Relations

The physiologic rest position
Physiologic rest position is
the position assumed by the
mandible when the head is in an
upright position, the muscles are
in equilibrium in tonic contraction
and the condyles are in a neutral
unstrained position.

The vertical dimension of occlusion (VDO)
and vertical dimension of rest (VDR)
VDR is the distance
measured between two
points when the
mandible is in
physiologic rest position.
VDO is the distance
measured between two
points when the
occluding members are
in contact.

It is a repeatable reference within an acceptable range.
It is a useful reference when establishing the vertical dimension of
occlusion.(VDO).
*Correct recording of the vertical relations determines the success of the
prosthesis.
*Failure to do so may compromise the success of the prosthesis:
If not measured accurately, the joint will be strained. No space is present
between teeth in dentures, discomfort, pain, generalized hyperemia and bone
resorption occurs.
Significance of physiologic rest position:

The interocclusal distance “Freeway space”
The difference between the occlusal vertical
dimension & the rest vertical dimension is the
interocclusal distance “freeway space.”
VDO = VDR - Freeway space.

Factors that affect the measurement of vertical
dimension of rest:
Patient position: Patient must sit in upright position. the mandible
influenced by gravity.
Unsupported head: Opening and closing muscles tend to be in a state
of minimal tonic contraction.
The duration of maintaining the rest position is usually short.
Any tension should be avoided. When a patient is tensed, under strain
nervous, tired, or irritable the values vary.
Special attention and enough time should be given to those patients
having neuromuscular disorder.
No valid method for all patients. So it is advisable to use several methods
and compare the result.

Methods of recording the VDR:
1. Facial measurements after swallowing and relaxing
(reference points using a divider)
2. Anatomic landmarks using Willis gauge.
3. Patient’s tactile sense (opening----closing).
4. Phonetics (emma, conversation).
5. Facial expression and Esthetics (skin tone and the lips
contour) should be relaxed.
6. Patient-perceived comfort.
7. Electromyography.

Facial measurements:
• Mark two points …
• One at tip of nose and one at tip of chin.
• Make patient sit upright comfortable
position in dental chair with head
unsupported.
• Patient is to asked swallow and relax and
drop his shoulders.
• Once dentist is sure that patient relaxed,
the distance between two points are
measured (using a divider). This
measurement is for vertical at rest.
• Usually 2 or 3 readings are taken… the
average is taken as reading. This
prevents error during taking
measurements.

Anatomic landmarks
• The Willis guide is designed to measure the distance from the pupils of
the eye to the rima oris and the distance from the anterior nasal spine
to the lower border of the mandible.
• When these measurements are equal, the jaws are considered at rest.

Now…..
• The mandibular occlusal rim is inserted and
patient is asked to bite on the rims.
• With patient in this occluding position, readings
at same two points marked earlier is made.
• This measurement is vertical at occlusion.
• Usually the VDO should be 2-4 mm less than
VDR.

Patient is asked to open his jaws
wide for a period of time till feeling
uncomfortable.
Ask him to close slowly until the jaws
reach a comfortable, relaxed
position.
Measure the distance between the
points of reference.
Tactile sense:

Phonetics:
Speech is used as an aid in establishing rest position,
many methods as:
1. Have the patient repeat Emma. When the lips contact ,
the jaw movement is stopped and the distance between
the reference points is measured.
2. Engage the patient in a conversation that will divert
patient’s attention. A pause in speech, followed by
relaxation as indicated by a drop of the mandible, is
indication for measurement.

By recognizing the relaxed facial expression
when a patients jaw are at rest, then recording
the VDR:
1. Lips will be even anteroposteriorly and at
rest.
2. The skin around the eyes and over the chin
will be relaxed.
Facial expressions:

• Rest position can be determined by
recording the minimal activity of muscles
of mastication.
Electromyography:

Methods of recording the vertical dimension of
occlusion:
A-Pre-extraction records:
1. Profile records:
• Profile radiographs.
• Profile photographs.
• Profile silhouette.
2. Acrylic face mask
3. Tattoo marks.
4. Articulated casts.
5. Facial measurements:
.
• Willis guage.
B-Post-extraction records:
I-Mechanical methods:
• Anatomical landmarks.
• Ridge relation and ridge parallelism.
• Former dentures.
• Cephalometric radiography.
II-Physiologic methods:
1. Phonetics:
2. Facial expression & esthetics.
3. Swallowing threshold.
4. Patient’s tactile sense.
5. Lytle’s neuromuscular perception
technique.
6. Power point technique of Boos.

A- Pre-extraction records
1. Profile records:
• Profile radiographs.
• Profile photographs.
• Profile silhouette.
2. Tattoo marks.
3. Articulated study casts.
4. Facial measurements:
.
• Willis guage.

• Profile photographs are made with
teeth in occlusion and enlarged to
life size.
• Measurements of anatomic
landmarks on the photograph are
compared with measurements of
the face, using the same
landmarks.
Disadvantage:
• Profile angles can change with
changes in the patient’s posture.

Profile radiographs of face:
• Profile radiographs are made
with teeth in occlusion and
compared with those made
with occlusal rims in position
• This method been much used
in research of vertical
dimension.
Disadvantages:
• Cannot be considered
adequate for routine clinical
use in prosthodontic treatment
because of radiation risks.

• Lead wires are adapted
to the patient’s profile
before extraction. The
outline is transferred to a
cardboard and cut out.
After extraction the cut
out is placed against
patient’s profile to check
vertical relation.
• Not commonly used
nowadays.

• Before extraction, the patient is
instructed to close his jaws into
maximum occlusion after two tattoo dye
marks are injected in the anterior labial
mucosa of the maxilla and mandible.
• The distance between these two marks
is measured and compared with
measurements made when recording
the VDO or tried in.

Two methods:
1. Articulated study casts: Before extraction
measurements between certain stable
anatomic landmarks on mounted study casts
can be used to indicate the amount of vertical
and horizontal overlap.
2. Mounted casts containing the extracted
natural teeth (inserted in their imprints in
compound impressions and poured with
stone) at the original JR to indicate the VDO.

• Using a pair of dividers,
the distance from the
bridge of the nose (A) to
the base of the nose (B)
plus the distance from
the base of the nose (A)
to the parting line of the
lips (C) is equal to the
distance from the bridge
of the nose (A) to the
inferior border of the chin
(E). [AB+AC=AE]

Willis gauge
To measure the VDO before extraction.

• Acrylic face mask is
made before extraction
using a facial
impression and cast.
• This method is not
practical.

B- Post-extraction records
I-Mechanical methods:
• Anatomical landmarks (
, Willis gauge and Wright formula)
• Ridge relation and ridge parallelism.
• Former dentures.
• Cephalometric radiography.
II-Physiologic methods:
1. Phonetics:
5. Lytle’s neuromuscular perception technique.

Wright formula
Interpupillary distance on a pohotograph
=
Brows-chin distance on a photograph
Interpupillary distance on the patient X
Where X represents the vertical height of the face.

i) Incisive papilla to mandibular incisors:
• Distance of incisive papilla from incisal edge of mandibular teeth approximately =
4mm
• Distance of papilla from incisal edge of maxillary teeth approximately = 6mm
• Mean vertical overlap = 2mm
• Drawbacks :
• Considerable individual variation.
• Not relevant in patients with severe resorption.

• The new residual alveolar ridges nearly parallel to each
other. This parallelism plus a 5 degree opening in the
posterior region often gives an indication to the correct
amount of jaw separation.
Drawbacks :
o Not reliable in case of:
1. Marked resorption.
2. Irregular intervals of missing teeth (irregular residual ridges).
o Edentulous ridges of the mandible and maxillae become progressively more
discrepant from the standpoint of width. (mandibular ridge become progressively
wider , and the maxillary ridge narrower, as bone resorption continues).

• Measurements are made between
the borders of the maxillary and
mandibular dentures by means of a
boley gauge.
• If the observations of the patient’s
face indicate that this distance is too
short or too long, a corresponding
alterations can be made in the new
denture.`

1. Phonetics:
• (Silverman’s closest speaking space).
5. Lytle’s neuromuscular perception technique.
7. Electromyography.

• Measures VDO when the mandible and the
muscles involved are in physiologic function of
speech.
• Should not be confused with the free way space
of the physiologic method, the free way space
establishes vertical dimension when the muscles
involved are at complete rest.

• Incisive guidance is established by arranging the anterior
teeth before recording vertical dimension. (Technique by
Pound and Murrel)
• The position of artificial teeth is determined by the position of
the maxillae when the patient says words beginning with “f”
or “v”
• The mandibular anterior teeth by the position of the
mandible when the patient says words beginning with “s”.

1. Stable record bases are made.
2. Contour the maxillary occlusal rim with
stable baseplate wax. The labiopalatal
and buccopalatal width are kept the
same as anterior and posterior teeth.
3. In mandibular record base, apply
baseplate wax to a height of 2 or 3 mm
over the superior surface. A section of
beeswax about ¾” high is placed in the
estimated location of four anterior teeth.
This section of beeswax is referred to as
speaking wax.

4. Place the maxillary occlusal rim in patient’s
mouth. Adjust the rim to provide lip support.
When the “f” and “v’ sounds are pronounced
the incisal edges of the maxillary anterior
teeth create a seal on the moist area of the
vermillion border of the lower lip.
5. Have the patient repeat the word “first” or
“Victor” and contour the wax to create the
seal.
6. Record the midline on the wax rim and
arrange the two artificial central incisors, one
on each side of the midline, with the incisal
edges perpendicular to the long axis of the
face. Prof Mohammed M Fouad 100

7. Remove the record base from mouth and
arrange the lateral incisors and canines.
8. Seat the mandibular record base with the
attached “speaking wax”. Have the patient
repeat the numbers 6 & 65 and adjust to
the “s” position. ie; When the “s” sounds
are pronounced the mandible moves
forward. The incisal edges of the anterior
teeth do not make contact.
9. Record the center line on the wax rim to
coincide with the midline of the maxillary
incisors. Prof Mohammed M Fouad 101

10. After removing the mandibular record base
from patient’s mouth, remove the speaking wax
from one side of the center line. Replace the
wax with central and lateral incisors, with the
neck of the teeth inclined towards the crest of
the residual ridge. Remove the remaining wax
and arrange the other central and lateral
incisors.
11. Adjust the wax rim to parallel the Camper’s
line. Notches placed in hard maxillary rim to aid
in repositioning the vertical dimension & central
occlusal records.
12. Place soft recording wax on the posterior
superior surface of the mandibular base to a
height that exceeds the anticipated occlusal
vertical dimension. Seal it to the hard wax.

13. Place the maxillary record base and assure
that it is stable and retained.
14. Seat the mandibular record base and ask the
patient to retrude the mandible from the “s”
position to a comfortable retruded relation and
then to close until a firm posterior contact is
encountered.
15. Remove the record base and check for
alignment and sufficiency.
16. Repeat step 4 until the incisal edges of the
mandibular teeth contact firmly against the
maxillary teeth or the palate ( in class II).

• Casts are mounted.
• Mount central bearing plates directly on the accurately adapted
record bases, adapting the plates to the patient’s inter arch
distance
• Adjust the bearing pin until the mouth is opened beyond the
physiologic rest position. When the patient signifies he has
reached excessive opening turn the pin back a half turn.
• These steps are repeated for obtaining consistent values.
• Soft fast setting plaster is injected to secure the relation.

Boos bimeter (power point):
Boos(1940) stated that maximum
biting force occurs at VDO. A device
that measures the biting force
(Bimeter) is attached to the
mandibular record base and a metal
plate to maxillary. A screw is turned
to adjust the vertical relation . The
maximum power point on the gauge
indicates the correct VDO.

• The theory is that when a person swallows, the teeth come together with very
light contact at the beginning of the swallowing cycle.
• The technique involves building a cone of soft wax on the lower denture base
so that it contacts the upper occlusion rim with the jaws too wide open.
• The flow of saliva is stimulated and repeated
action of swallowing will gradually reduce the
height of wax cone to allow the mandible to
reach the level of OVD.
• It is difficult to find consistency in the final
vertical positioning of the mandible by this
method.

Evaluation of the vertical dimension:
1. The freeway space (The interocclusal distance).
2. The closest speaking space.
3. Patient tactile sense.
4. Swallowing followed by relaxing (cones of soft wax).
5. Phonetics (3.33) (5.55) (Emma).
6. Esthetics (tone of facial skin, lip support and Fullness).

Effect of increase in VDO (decrease in IOD):
1. Discomfort to the patient.
2. Difficulty in swallowing and speech.
3. The appearance of elongated face & at rest the lips
are parted.
4. Stretching in facial muscles.
5. “Clicking” of denture teeth (even during speech) and
rapid wearing of teeth.
6. Constant pressure will lead to rapid alveolar bone
resorption.
7. Soreness of the basal seat tissues.
8. Pain and clicking in TMJ.

Effect of decrease in VDO (increase in IOD):
1. Inefficiency: decrease in the force exerted with the
teeth.
2. Limited tongue space.
3. Cheek biting during mastication.
4. Facial distortion appears (over closure)
5. The muscles of facial expression lose their tonicity and
the face appears flabby instead of firm and full.
6. Pain and damaging to the TMJ.

The horizontal jaw relations

Jaw relations
Protrusive Lateral
RT LT

Horizontal jaw relation:
DEFINITION: Relationship of mandible to
maxilla in a horizontal plane.
DESCRIBED AS relationship of mandible
to maxilla in the anteroposterior and lateral
directions.
TYPES:
1. Centric jaw relation
2. Eccentric jaw relation

Centric relation

Definition of centric relation (CR):
• The condyles are in the
midmost position and
articulate with the thinnest
avascular portion of their
respective disc (coronal
view).
• With the complex: in the
anterior superior position
against the slopes of
articular eminences
(Sagittal view).
It is the
most
retruded
unstrained
relation of
the
mandible
to maxilla
When:

Significance of centric relation in edentulous patient :
1. It is a bone to bone relation, independent on teeth.
2. Repeatable, Recordable and can be verified.
3. Is a definite learned position.
4. Patient can voluntarily and reflexily return to this position.
5. In CR condyles exhibit pure rotation without any translation.
6. It acts as proprioceptive centre to guide occlusal movements.
7. Functional movements are performed in this position as it is most
unstrained position.
8. Act as a reference relation for establishing CO in CD.
9. The cast should be mounted in centric relation.

Factors influencing centric relation record:
1. The size of the residual alveolar arch.
2. The resiliency of the supporting tissues.
3. The size and position of the tongue.
4. The amount and character of the saliva.
5. The maxillomandibular relationship.
6. The TMJ and its neuromuscular mechanisms.
7. The stability of the recording bases.
8. The character of the pressure applied.
9. The posture of the patient.
10. The health and cooperation of the patient.
11. The technique & devices used.
12. The skill of the dentist.
118Prof Mohammed M Fouad

Recording of centric relation:
Two phases :
1.Assisting the patient to retrude the
mandible .
2.Recording methods.

Methods of assisting the patient to
retrude the mandible:
1. General body relaxation.
2. Ask the patient to let his jaw relax, pull it back and close
slowly on the posterior rims (not to bite) until the blocks
gently touch together. Bite may lead to slight protrusion.
3. Ask the patient to curl the tongue up and back, and close
until the blocks gently touch together.

4. Massage the temporal and masseter muscles to
relax them, as the patient closes gently.
5. Fatigue by ask the patient to protrude and
retrude the mandible repeatedly.
6. Tapping the rims or back teeth repeatedly.
7. Asking the patient to get the feeling of pushing
his upper jaw out and closing his back teeth
together.
Prof Mohammed M Fouad
121

8. Place the index fingers gently on the inner
side of the ramus of the mandible and ask the
patient to close.
9. Ask the patient to swallow and keep the
record blocks in contact at the end of the
swallow.
10. Tilt the patient’s head well back and ask him
to look at a point behind the head.

Difficulties in retruding the mandible:-
1. Biological causes:
• Lack of muscle co-ordination.
• Habitual eccentric jaw relation.
2. Psychological problems:
• Lack of proper instruction by dentist.
• Inability to follow dentist.
3. Mechanical problem:
• Poorly fitting record base.

Primary requirements of the recorded CR:
• Accuracy.
• Equalized vertical pressure.
• Recording medium of uniform consistency.
• Retain the record in an undistorted
condition.

Bite registration materials:
• Waxes (e.g. Aluwax)
• Quick setting plaster.
• Impression compound.
• Bite registration silicone.
• Bite registration ZnOE
paste.

Methods of recording centric relation:
 Physiological methods:
• Tactile sense interocclusal check record.
• Pressureless (static interocclusal bite record) method.
• Pressure method.
 Functional (Chew in) methods: Needle house method and
Patterson method.
 Terminal hinge axis method.
 Swallowing (deglutition) method.
 Graphic methods: arrow point (Intraoral and extraoral) and
pantographic recordings.
 Radiographic: Cephalometrics.

Physiological methods:
Based on:
o Proprioceptive impulse of patient.
o Kinesthetic sense of mandibular movement.
o Sense of touch of patient.
Methods:
o Tactile sense or interocclusal check record
method.
o Pressureless (static) method.
o Pressure method.

Tactile sense interocclusal check
record method:
Indications:
 Abnormally related jaws.
 Displaceable flabby tissue.
 Large tongue.
 Uncontrolled mandibular movements.
 In patients already using a complete denture.
Material used:
• Waxes: low fusing.
• Impression compound.
• Dental plaster.
• ZnOE paste.

Procedure:
A- Recording tentative jaw relation:
• Maxillary occlusal rim inserted to patients mouth.
• VDR is established. Mandibular occlusal rim
inserted and reduced accordingly.
• Tentative (uncertain) CR is recorded by asking
the patient to retrude the mandible. Casts are
articulated based on this tentative record.
• Artificial teeth are arranged.

B- Making the interocclusal check record:
• Trial dentures are inserted into the mouth.
• Aluwax is added on the occlusal surface of
mandibular teeth.
• Patient is asked to retrude mandible and close
on the wax till tooth contact occurs.
• Trial dentures removed and allowed to cool.
• Remount of lower cast; if needed.

Pressureless (Static interocclusal bite record):
1- Nick & notch method (wax wafer method) :-
(The most commonly used method)
• Up to 3mm of wax removed from the premolar region of
mandibular occlusal rim till the distal end.
• 1 or 2 notches are cut on the corresponding area of
maxillary occlusal rim.
• One nick (V shaped groove) is cut anterior to the notch.
• These grooves prevent lateral movement while notches
prevent anteroposterior movement.

• Nicks and notches are lubricated with petroleum.
• Prepared occlusal rim are inserted into patient’s mouth.
• Seat the patient in upright position and learn and instruct
him to close his mandible in maximum retruded position.
• Softened Aluwax is placed on the mandibular rim.
• Mandibular occlusal rim is inserted into patients mouth
and closed in centric relation.
• Remove occlusal rims, cool it and articulate.

Checking the CR record

Pressureless (Static) method:
2. Stapler pin method:
• After recording centric
relation, occlusal rims are
indexed using a bunch of
stapler pins.
• This method is not preferred
because centric relation
record cannot be verified.

Pressure method:
(To produce the same displacement of the soft tissue as by the
dentures during function.)
• Lower occlusal rim fabricate excess in height.
• Upper occlusal rim inserted.
• Entire lower occlusal rim is softened in water bath &
inserted in mouth.
• Patient is asked to close on the softened wax in centric
relation and guided till the predetermined vertical
dimension.
• Remove occlusal rims, cool it and articulate.

Functional (Chew in) methods:
 These methods utilize the functional border
movements of jaws (such as protrusive and
lateral excursions) to record the centric relation.
Functional Methods are:
• Meyer’s method.
• Needle house method.
• Patterson method.

Meyer’s method:
• Soft wax is used on the occlusion rims to
establish a generated path.
• Tin foil is placed over the softened wax and
lubricated.
• The patient is instructed to perform the functional
movements to produce a wax path.
• Plaster index of the wax path is made and the
teeth are set to it.

Needles-House method:
• Occlusal rims made from impression compound at a correct VDO.
• Four metal styli of 2mm height are embedded into premolar and
molar areas of maxillary occlusal rim.
• Occlusal rims are inserted into mouth and patient is asked to close
on occlusal rims and make anteroposterior and lateral mandibular
movements until the rims return to the established VDO.
• Diamond shaped tracings are formed on the mandibular occlusal
rim.
• The anterior apex of each tracing indicates the most posterior
position of the mandible.

Needle house method

Patterson’s method:
• Occlusal rim made of modeling compound and adjusted to the
correct VDO.
• A furrow or channel is cut along the center of all of mandibular
occlusal rim leaving the outer margins of the compound.
• A mixture of carborundum and dental plaster is loaded into the
channel exceeding 1mm height.
• The patient is asked to perform mandibular movements till
predetermined vertical dimension.
• The teeth are set following these compensatory curves.

Patterson’s method:

Terminal hinge axis method (using kinematic
face bow):
 Kinematic facebow is attached to the lower jaw by
means of clutch.
 Graph of Grid paper is placed near
temperomandibular joint region detects the stylus
movement.
 Patient is asked to open and close the mandible
at centric.
 The stylus is adjusted until the tip rotates instead
of arcing.
 This point identified as the hinge axis is marked
on the skin.

Swallowing Method

Graphic methods:
Two types of graphic methods:
1) Arrow point tracers: graphic records of
mandibular movements in one plane.
2) Pantograph: A graphic record of
mandibular movements in 3D planes.

Arrow point tracings:
• This type of graphic records is made in horizontal
plane only, using gothic arch tracers.
• Gothic arch tracer consists of contacting point
attached to one dental arch and plate attached to
opposing dental arch. The plate provides surface on
which the tracing of mandibular movements is
recorded.
• Two types: Intraoral and extraoral arrow point (gothic
arch) tracers.

Intra oral arrow point tracer:
• Tracer is placed within the mouth.
• Central bearing point & plate is inserted into patients mouth.
• Central bearing point is adjusted such that it contact the central
bearing plate at predetermined vertical dimension.
• With anteroposterior and lateral mandibular movements, central
bearing point will draw the tracing pattern on central bearing
plate. The tracing resembles
an arrow point with a sharp apex.

Extra oral arrow point tracer:
• Similar to intra oral tracer, additionally have an
attachment that project outside mouth.
• Record bases attached to recording devices inserted in
patients mouth.
• Recording plate which projects extra orally is coated with
precipitated chalk and denatured alcohol.
• Patient asked to perform all movements.
• Examine for sharp apex.

Extra oral arrow point tracer

Pantographic tracing:
• A graphic record of mandibular movements in more than one
plane by styli registering on recordable tables of a
pantograph.
• Most accurate method available to provide information for
the programming of the articulator.
• Make the rim contact at desired vertical relationship.
• Strips of celluloid paper are placed between the rims and pulled out while
patient close and restrain the celluloid from slipping away. Mandible goes
to centric relation.
• Softened wax is placed on mandibular occlusal rim and patient is asked
to bite in centric relation.

Pantographic tracing
It has 6 flags:
• 4 near condyle
• 2 in anterior region

Factors to be considered while carrying out
tracing by graphic methods:
1. Stability of denture base. Displacement of record base may result from
pressure if central bearing points is off center when mandible moves in eccentric
relation to maxilla.
2. Resistance of rims.
3. Difficulty in placing central bearing device. If central bearing
device is not used the occlusal rims offer more resistance to horizontal
movements.
4. Height of residual alveolar ridge. It is difficult to stabilize record
base against horizontal forces on residual ridges that have no vertical height
and tissue that are pendulous.

Factors to be considered while carrying
out tracing by graphic methods:
5. Tongue interference. Difficult to stabilize record
base with pt. who have uncooperative tongue.
6. Efficiency of recording device. Tracing is not
accepted unless a pointed apex is developed.
7. Lack of coordinated movements result in
Double tracing.
8. Graphic method can record eccentric
relation of mandible to maxilla.

Contraindications of Graphic method:
1. Instability of denture
bases due to
• Severely resorbed
ridges.
• Excessively flabby
ridges.
1. Decreased arch space.
2. TMJ disorders.
3. Abnormal jaw relations.

Dental procedures In which CR is considered as
basic reference:
1. Missing of all the upper or lower posterior teeth or both.
2. Cases where the VDO is affected.
3. Severe dental wear.
4. Signs and symptoms in masticatory system (TMJ, NMS,
Teeth) where the occ. is involved.
5. Cases need full mouth rehabilitation.
6. In orthodontic treatment where discrepancy between CR
and MIC position is more than 3mm.

A basic Principle
In all cases where the CR is the reference
the MIP must coincide with CR position.

Eccentric jaw relations

Jaw relations
Protrusive Lateral
RT LT

Eccentric jaw relations:
• “Any relationship of mandible to maxilla other than centric
relation” including protrusive and lateral relations.
• Help to adjust the lateral and horizontal condylar
inclination in the adjustable articulators.
• Thus helps the articulator to reproduce eccentric
movements of mandible and establish balanced occlusion.
• Recorded using functional or tactile method.

Protrusive jaw relation:
• Register the influence
of the condylar paths
over the movements
of the mandible
• Christensen’s
phenomenon.

Protrusive interocclusal record (Hanau)

Lateral interocclusal
records (using Hanau
equation and semi
adjustable articulator.)
L = H/8 + 12
( H – Horizontal condylar
inclination
L – Lateral condylar
inclination)

Protrusive interocclusal record
(Whip mix)

Lateral jaw relations
• Influence the intercuspation of teeth in
working mastication.
• Used to program the fully adjustable
articulators

Lateral interocclusal records (Whip mix)
• Set side shift guide at 45o
• Mark 6mm from centric relation along Left
Lateral tracing and centre the hole of
plastic piece over it.
• Right condylar ball is in protrusion.
• Side shift guide brought in contact with the
ball.

CONCLUSION
 Recording jaw relation is one of the most important step in
fabrication of complete denture.
 There are various technique used to record jaw relation.
 By recording proper jaw relation, functional efficiency,
proper facial appearance & longevity of the prosthesis is
increased.
 Unsatisfactory maxillomandibular relations will eventually
lead to failure of complete denture.

REFERENCES
• Syllabus of complete dentures, Charles M. Heartwell, Jr, Arthur O.Rahn (4th edition)
• Prosthodontic treatment for edentulous patients, Zarb-Bolender (12th edition)
• Winkler S, Essentials of Complete Denture Prosthodontics, 2nd
edition,2009
• Nair CK. Programming the semiadjustable articulator. Trends in Prosthodontics
2011;2(1):12-14.
• Nair CK et al. Relationship between protrusive record and horizontal
condylar guidance angle. Trends in Prosthodontics 2011;2(1):15-16
• Nair KC, A primer on complete denture fabrication, 1st edition, 2013, Ahuja
publication, India.
• Sharry JJ, Complete Denture Prosthodontics, 3rd edition, USA, Mcgraw-Hill
Book Company, 1974.
• Saizer P. Centric relation and condylar movement: anatomic
mechanism. J Prosthet Dent 1971;26(6):581-91.
• Google search and our notebook of prosthodontics.

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