Vinay Pavan Kumar K

2nd year P G student

Dept of Prosthodontics

AECS Maaruti College of Dental Sciences

Purpose of Recording the Jaw

Relations To establish and maintain a harmonious

relationship

To ensure that all the effects of occlusal loading be distributed

To best control the undesirable effects of rotational or torquing forces on the prosthesis.

To prevent any deflective contacts of the teeth during centric or eccentric closures

Recording Jaw relation

Before construction of framework - mounted on

an articulator

Definitive jaw relation – after functional

impression and altered cast

Methods of recording Jaw

relation

Direct apposition of cast.

This should not influence the path of closure of

mandible

Interocclusal records with posterior teeth

remaining

Occlusal relations using occlusion rims on

record base

one or more distal extension areas are present

a tooth supported edentulous space is large

when opposing teeth do not meet

Jaw relations records made entirely on

occlusion rims

when either arch has only anterior teeth present

opposing posterior teeth do not meet

Establishing Occlusion by the Recording of OcclusalPathways

Support the wax occlusion rim with a denture base

occlusion rim must be worn for 24 hours or longer

After 24 hours, the occlusal surface of the wax rim should show a

continuous gloss, which indicates functional contact with the

opposing teeth in all extremes of movement.

After a second 24- to 48-hour period of wear, the registration

should be complete and acceptable

Vertical Dimension

VDO

VDR

Freeway space

Altering the existing vertical

dimension of occlusion

Symptoms of diminished VDO like tired aching muscles

unexplained pain in the head and neck

region

shortened nose-chin distance

(appearance of premature aging)

Excessive Free way Space or ‘over-

closure’ of the jaws

Wearing of the teeth does not mean that

VDO should be increased – unless the free-

way space is greater than 4mm.

How to alter the existing VDO

1. Confirm the loss of VD by taking history, cephalometricexamination, and the presence of excessive free-way space.

2. Increase the existing VDO temporarily by fabricating an acrylic resin occlusal overlay appliance in maximum intercuspation, ensuring that 4mm of freeway space must exist.

3. Restore the desired VDO permanently with

the help of fixed or removable prosthesis only

after the physiologic response of the patient to

this appliance is positive.

Facebow transfer

To relate the maxillary cast to the

condylar elements of the articulator at

the same orientation that the maxillary

teeth have to the mandibular condyles of

the patient.

Horizontal jaw relation

centric relation centric occlusion

centric relation or centric

occlusion ?

The most delicate proprioception in your body is between the upper and lower teeth.

In more than 90% of people, C.O is 0.5 - 2mm in

front of the CR

Centric relationCentric occlusion

C.O should be recorded when there are cusps on remaining natural teeth that can guide the mandible back to its position.

C.R should be recorded for distal extension RPD, or when the opposing arch is edentulous.

When Not to Use Centric

Relation

Stable occlusion

Posterior centric stops present

No valid reason to change

Use maximum intercuspation

Try In Appointment

if the RPD opposes a complete denture

all posterior teeth in both arches are being replaced

if no opposing natural teeth are in contact

Provides verification of the jaw relation recorded

provides an, opportunity to view and approve the esthetic

size, color, and arrangement of the anterior teeth

Phonetic inspection

Desirable occlusal contact relationship

for removable partial dentures

Simultaneous bilateral contact – centric occlusion

Tooth supported partial denture – occlusion as in

natural dentition

Maxillary complete denture opposes partial denture

- bilateral balanced occlusion in eccentric positions

Bilateral upper distal extension base -

simultaneous working and balancing side contact

Only working contacts need to be formulated for

the maxillary or mandibular unilateral distal

extension removable partial denture

Bilateral distal extension mandibular RPD opposed

by natural dentition in the maxillary arch - Working

contacts are achieved

Artificial posterior teeth should not be arranged on

the sharp upward incline of the mandibular residual

ridge or over the retro molar pad

Possible scenarios adapted from Henderson place

emphasis on RPD stability

Three possible sequelae of occlusal error

If the premature contact is on a natural tooth, damage to

the tooth or its periodontal ligament may occur.

If the saddle bears the brunt of the force of closure, there

will be localised mucosal inflammation and resorption of

the underlying bone.

If the patient attempts to steer the mandible around the

premature contact until a more comfortable occlusal

position is found, this abnormal closing pattern throws

increased demands on certain muscles of mastication,

which may result in the patient complaining of facial pain.

Maxillary complete denture

opposing a RPD

Occlusal consideration in implant

retained partial denture

axial displacement of teeth in the socket are 25-100 μm,

while that of the osseointegrated dental implants has

been reported approximately 3-5 μm

natural tooth moves 56-108 μm and rotates at the apical

third of the root upon a lateral load

Dental implant moves 10-50 μm under a similar lateral

load

Conclusion

An ‘ideal occlusion’ in removable

prosthodontics is one which reduced de-

stabilisating forces to a level that is

within the denture’s retentive capacity

References Carr AB, Brown DT, McCracken’s Removable

Partial Prosthodontics, 12th edition, Canada,

Elsevier Publishers, 2011, pp:242-252

Stewart, Rudd, Kuebkar, Clinical Removable Partial

Prosthodontics, 2nd edition, India, All India

Publishers and Distributors, 2001, pp:367- 396

Jones DJ,Gracia LT, Removable Partial Dentures :

A Clinician’s guide, 1st edition, Singapore, Wiley-

Blackwell, 2009, pp : 90-94

Jacobs, R. and Van Steenberghe D. (2006),

From osseoperception to implant-mediated

sensory-motor interactions and related clinical

implications. Journal of Oral Rehabilitation,

33: 282–292.

Davies S.J, Gray .R and McCord J.F, Good

occlusal practice in removable prosthodontics

British Dental Journal 2001; 191: 491–502

Davenport .J.C etal The removable partial

denture equation, British Dental Journal 2000;

189: 414–424