CENTRIC RELATION
Centric relation is the most posterior
relation of the mandible to the maxilla when
the condyles are in the mos
t posterior
t posterior
unstrained position in the glenoid fossa
Definition
In dentulous patient s the proprioceptive impulses are
obtained from the periodontal ligament and TMJ. It
guide the periodontal ligament
Edentulous patients do not have any proprioceptive
movements.
The source of the proprioceptive impulses for an
edentulous patient is transferred to the
Temporomandibular joint.
The centric relation position acts as a proprioceptive
centre to guide the mandibular movements.
Importance of centric relation
It is a reproducible and recordable position, which --
can be repeatedly arrived at and thus serves as a reliable
guide to develop centric occlusion in complete dentures.
Centric relation become starting point to plan and --
execute the occlusion.
Functional movements like chewing and swallowing --
are performed in this position, because it is the most
unstraind position.
The muscles that act on the temporomandibular joint --
are arranged in such a way that it is easy to move the
mandibule to the centric position.
Significance of Centric
Relation
. The final act of masticatory stroke ends in centric --
relation.
If mandibule has move from one eccentric position to --
another it should go to the centric relation before
advancing to the target eccentric position
Act as a centre from which all movements can be done --
Significance of Centric
Relation
The patient is instructed to let his or her jaw relax, pull --
it back and close slowly on the back teeth.
The patient is instructed to get the feeling of pushing --
his upper jaw out and then close the mouth with back
teeth in contact.
Assist the patient to protrude and retrude the --
mandible repeatedly with the operator holding the
finger lightly against the chin.
Boo's series of stretch exercises: The patient is instructec --
to open the mouth wide and relax, to move the jaws to left and
relax, to move the jaw to the right and relax and to move the
jaw forward and relax in series of movements. The results to
be expected are for the patient to be able to follow the dentist's
directions in moving the jaw to centric relation and to the
desired eccentric positions
The patient can be instructed to turn the tongue towards --
the posterior border of the upper denture base and close the
rims together until they meet. The disadvantage with this
method is the likelihood of displacing the mandibular record
base by the action of the tongue.
The patient is told to swallow and conclude the act with --
the occlusal rims in contact. However, the person can swallow
when the mandible is not completely retruded. This method
must be verified by other techniques
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