Check bite technique

What’s the jaw relation ?
Jaw relation is any spatial relationship of the mandible
to the maxilla.
Jaw relation record :
It’s the registration of any positional relationship of
mandible in relation to the maxilla.
This record is made in any horizontal, lateral or vertical
orientation.

Orientation
• affects the mean of
curvature of occlusal
surface of the teeth
vertical
• V.D.O
• V.D.R
Horizontal
• Centric
• Eccentric
Jaw relation
record

Steps of complete denture construction
5
7
6
a)Mounting on the articulator.
b)Setting up of teeth.
c) Waxing up .
Jaw relation ship .
1) Check record bases.
2) Determination of height and
orientation of occlusal plane.
3) Mounting maxillary cast.
4) Determination of vertical
dimension of occlusion.
5) Equalize pressure of
occluding surfaces.
6) Recording centric relation.
a) Pouring of master casts.
b)Construction of occlusion
blocks.
The most important
clinical step

“
Why the centric relation is the most
important ?

Centric
relation is
important
because:
1) It is learnable, repeatable and recordable position
which remains constant throughout life .
2) It acts as a center from which all movements can
be made.
3) If the mandible has to move from one eccentric
position to another it should go to the centric relation
before advancing to the target eccentric postion.
4) Functional movements like chewing and
swallowing are performed in this position
because it is the most unstrained position.

Centric
relation is
important
because :
5) The muscles that act on the temporomandibular joint
are arranged in such a way that it is easy to move the
mandible to the centric position from where all
movements can be made.
6) The casts should be mounted in centric relation
because it is the point from which all the movements can
be made or simulated in the articulator.
7) It is helpful in adjusting condylar guidance in an
articulator to produce balanced occlusion.

check bite
technique
( physiological method of recording
centric and eccentric relations )

“Check bite technique:
Is the most commonly used physiological method of recording
centric relation (bite registration )
It’s based on :
1)The proprioceptive impulses of the patient.
2)Kinesthetic sense of mandibular movement
3) The visual acuity and sense of touch of the dentist.

Ideal requirements of bite registration materials
2
1
3
4
5
6
7
8
Cost
Dimensional
changes
Resistance
Record Manipulation
Biology
Working time
Limited
High
Minimal
easy
Accurate
Healthy
on
tissues
Sufficient
and
appropriate
Low .
Rigidity
after
Setting
Limited resistance before setting to avoid
displacing the teeth or mandible during
closure.
1
Rigid or resilient after setting.2
Minimal dimensional change after
setting. (dimensional stability )
3
low viscosity
no adherence to the teeth.
plasticity
4
Ideal recording of occlusal & incisal surface
of the teeth
5
No adverse effects on the tissues involved
in recording procedures and acceptability to
the patient
6
APPROPRIATE WORKING TIME
WITH PRECISION OF DETAILS
7
Low cost .
8

Materials Advantages Disadvantages
1- waxes as (Allu wax) Easy in manipulation unstable and inconsistent due to
passive and active movement of
mandible
2- impression compound or ZOE Not easily distort as wax need more time and maintaining the
patient’s bite stable until set occur.
3-silicon elastomers (addition or
condensation):
fast setting, dimensional stable, high hardness
,accuracy, stability
4-impression plaster: accurate ,rigid no distortion brittle
5-acrylic resin: accurate and rigid. dimensional changes.
6-poly ether: accuracy ,stability ,no need for carrier
and high fluidity
Materials used in check bite technique

Indications
of check bite
technique :
▹Indications of check bite technique :
▹1) Abnormally related jaws.
▹2)Displaceable, flabby tissues.
▹3) Large tongue.
▹4) Uncontrollable mandibular movements.
▹5) It can also be done for patients already using a complete
denture.

Steps of recording centric
relation
1) Seat the patient at upright position to avoid high vertical dimension of restAnd
also avoid low V.D.R.

relation
2) Adjust the orientation of the jaw by using fox plane :
The anterior occlusal plane should be parallel to interpupillary line.
The posterior occlusal plane should be parallel to ala tragus line.

relation
3) Start measuring VDR by guiding the patient to rest position by:
1) 2 dots technique : the dentist must be satisfied that the patient is relaxed
a)The dentist draws 2 points one on the tip of the nose and the other is on the
chin.
b) Ask the patient to swallow and relax .
2) Pronunciation of letter M : it’s observed that M leaves the lips in contact
therefore the word is extended to Emma .
Some patients retrude the mandible while pronouncing P letter therefore the
word ( Mississippi is popular ).
3) Esthetics :
checking that the face is relaxed and the muscles are unstrained .

relation
Ruler !
Wilis
gauge!

relation
By sequence we can exclude the
measurement of V.D.O by
subtracting the measurement of
free way space (which is ranging
from 2:4 mm) from the previous
V.D.R
VD at occlusion = VD at
rest - Freeway Space

Procedure is composed of :
2 steps 1) tentative records using occlusion blocks.
2) pressure method
3) pressurless method .
4) interocclusal check record for the teeth during try- in.
Procedure

Methods of
mandibular
retrusion
1) Relaxing the patient ( Making him feel comfortable)
2) The patient is asked to try to bring his upper jaw
forward while occluding on the posterior teeth.
3) The patient should be instructed to touch the
posterior border of the upper record base with his
tongue.
4) The mandibular occlusal rim should be tapped
gently with a finger this would automatically make the
patient to retrude.
The temporalis and the masseter are palpated to relax
them.
5) Swallowing.

1) Tentative Jaw Relation:
Rapid method done using base plate wax .
1)The maxillary occlusal rim is inserted into the
patient’s mouth.
2)The vertical dimension of rest is established and the mandibular rim is reduced further
for excess inter-occlusal distance.
3) A tentative centric relation is recorded by using one of the methods to retrude the
mandible.
4) The occlusal rims are articulated using the tentative jaw relations and the artificial teeth
are arranged.

Static or pressureless method
Once the patient attains the centric
relation position,the denture bases with
occlusal rims are indexed/sealed in this
position by :
a) The nick and notch method.
b) the stapler pin method can be used to
index/seal the occolusal rims.

“
Nick and notch method : This is the
most commonly used method of
indexing the recorded centric jaw
relation.

1) Up to 3 mm of wax is removed on
either side of the mandibular occlusal
rim from the premolar region till the
distal end.
This depression created on the
occlusal rim due to removal of wax is
called trough.
Static or pressurless method
2) 2 notches are created on the
upper occlusion rim
2 nicks are created also
The notch prevents
anteroposterior movement
And the nick prevent lateral
movement

3) The prepared occlusal rims are inserted into
the patient’s mouth and the patient is taught to
close his mandible at the maximum retruded
position.
4) The mandible is then guided into position with
the index fingers supporting the occlusal rims.
5) the pateint is asked to repeatedly practice
centric relation till the dentist is satisfied.
6) The mandibular occlusal rim is removed
from the patient’s mouth.
( Aluwax) is placed on troughs created in the
mandibular rim
7) About 4.5 mm of Aluwax should be placed
on the trough so that about 1.5 mm of Aluwax
will be projecting above the mandibular
occlusal rim.

8) The mandibular occlusal rim is placed in a water
bath to soften the wax and inserted into the
patient’s mouth.
9) The patient is asked to close in centric relation
with professional guidance.
The mouth should close such that the anterior parts
of the occlusal rims almost touch but not press.
10) The Alluwax projecting above the trough
of the mandibular rim will flow into the nick
and notches.
11) The occlusal rims are removed and
placed in a cold-water bath till the wax
hardens.
Excess wax is trimmed bucally and lingually.

Pressure method
1) after establishing the vertical dimension the upper
occlusal rim is inserted into the patient’s mouth.
2) The lower occlusal rim is fabricated to be of excess
height or it’s reduced 2mm to add Alluwax , notches on
upper rim are also made
3)The entire lower occlusal rim is softened in a water
bath and inserted carefully into the patient’s mouth.
4) The patient is guided to close his mouth in centric
relation. The dentist should gently guide the mandible.
5) The patient is asked to close on the soft wax
After the patient closes his mouth till the predetermined
vertical dimension, both the occlusal rims are removed,
cooled and articulated.

The Inter-occlusal check record

Factors
affecting the
success of
inter-occlusal
record method
1)Uniform consistency of the recording
material.
2)Accurate vertical jaw relation records.
3)Stability and fit of the record base.
4)Presence of reference points embedded
in the record like pins or styli.

Evaluation
of wax wafer
technique :
to make sure that the methods were performed accurately:
1) notice the interlocking of the pyramid with V notch ,the
pyramid must close directly in the centre of V notch and
donot touch the incline of the V notch.
2) notice the patient if he perform effort while performing
centric relation.(doesn’t make over retrusion).
3)notice the patient if he perform an effort during swallowing.
4) dividing the face in three equal thirds.
5) remeasure the predetermined VDR to make sure.

6) from the facial (anterior side):
notice the following:
1-the lips ,should not be
strained
2- the naso labial sulcus.
3-the corner of the mouth.
4-vermellion border.
5- facial muscles.
6-cheeck must not be dropped
inward.
Evaluation of mandibular
retrusion
strained lip after
denture insertion
proper curvature of
nasolabial sulcus

7)from the profile side:
notice the following:
1-the upper lip should
overlap the lower lip .
2-proper curvature of
mento-labial sulcus.
3-no chin-nose approximation

8) from inter occlusal :
when the occlusion blocks in the patient mouth we have to check the sealing
accuracy between the upper and lower occlusion blocks
so come with a knife and insert it between the ccclusion blocks to check the
accuracy while the patient is in centric occlusion.
the take them from the patient mouth and mount them on the articulator and
check the sealing accuracy between the following:
1-the upper and lower occlusion blocks.
2-the occlusion block and the trial denture base.
3-the trial denture base and the cast.

checking the inter occlusal sealing
of occlusion blocks
checking the interocclusal
sealing on the articulator
proper sealing
between 1,2,3

Check bite technique

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