Hinge axis recording “the essential need in prosthodontics

Battered Precision is the key to prosthodontics and it is thus imperative that restorations are made as accurately as possible. This is best achieved by the use of hinge axis concept and thus it should be incorporated into routine clinical practice to achieve optimum results. The transverse hinge axis in dentisry has always been a subject of controversy with its existence itself and existence of single or multiple hinge axes. The presence or absence of a hinge axis of the mandible is of prime importance in clinical phases of dentistry and can be located with any degree of accuracy. Most of the transographs concept is based on the asymmetry of the condyles. The anatomic condylar asymmetry, as well as the observation that the mandible may open or close at a slight angle to an arbitrary vertical plane of the face has lead page to theorize that there are two transverse hinge axis, one for each condyle. Hinge axis record reveals that translatory and rotational components in varying proportions affect the path and location of the condyle in movement. In order to program a dental articulator to duplicate the hinge opening and closure of the mandible, it is necessary to make a hinge axis record and transfer this information to the articulator. The transverse hinge axis point may be located most precisely by a kinematic process, or its location may be estimated by some arbitrary method. The following methods are explained in sequence.