check bite technique

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

Dimensionalchanges

Resistance

Record Manipulation

Biology

Working time

Limited

High

Minimal

easyAccurate

Healthy

on

tissues

Sufficient

and

appropriate

Low .

Rigidityafter Setting

Limited resistance before setting to avoid

displacing the teeth or mandible duringclosure.

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 surfaceof 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

relation1) Seat the patient at upright position to avoid high vertical dimension of restAnd

also avoid low V.D.R.


relation2) 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.


relation3) 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

“

Thank you

check bite technique

Health & Medicine