Centric relation


Centric relation

In dentistry, centric relation is the mandibular jaw position in which the head of the condyle is situated as far anterior and superior as it possibly can within the mandibular fossa/glenoid fossa.

This position is used when restoring edentulous patients with removable or either implant-supported hybrid or fixed prostheses. Because the dentist want to be able to reproducibly relate the patient's maxilla and mandible, but the patient does not have teeth with which to establish his or her own vertical dimension of occlusion, another method has been devised to achieve this goal. The condyle can only be in the same place as it was the last time it was positioned by the dentist if it is consistently moved to the most superior and anterior position within the fossa.

Centric relation is an old concept in dentistry based on an old mechanical viewpoint of dentistry. There are over 26 different definitions of Centric Relation since the term was first developed as a starting point for making dentures. It is not a physiologic position but rather a border position that is used for reproducibility. The Temporomandibular Joint, does not normally function in a Centric Relation position. Long centric is a term that describes a functional position that patients restored in Centric Relation frequently migrate to. Centric Relation is a border position that is inherently unstable. Mandibular fossa is put anterior and superior as possible. (First aid for the NERB I)
Centric Relation believers state that the relationship of the mandible to the maxilla when the properly aligned condyle-disc assemblies are in the most superior position against the eminentiae irrespective of Occlusal Vertical Dimension (OVD) or tooth position.
At the most superior position, the condyle-disc assemblies are braced medially, thus centric relation is also the midmost position. A properly aligned condyle-disc assembly in centric relation can resist maximum loading by the elevator muscles with no sign of discomfort.[1]

References

  1. ^ Functional Occlusion: From TMJ to Smile Design (Hardcover), by Peter E. Dawson (Author), Hardcover: 648 pages, Publisher: Mosby; 1 edition (August 1, 2006), Language: English, ISBN 0323033717, ISBN 978-0323033718
  • Davis Henderson, Victor L. Steffel. McCRACKEN's Removable partial prosthodontics, 4th Edition, 1973.