2007 Volume 27 Issue 1-2 Pages 32-39
We meet a tremendous number of cases that require occlusal reconstruction in daily clinical procedure. No matter what kinds of dental prosthesis are used, no matter how many teeth are missing, “a stable mandibular position” is the most essential for occlusal reconstruction. In the literature on occlusion this, somewhat obvious, point and its significance are clearly agreed upon. However, assessing the mandibular position in daily clinical procedure still tends to be thought of as “something special”.
The mandibular position should be considered from the muscle position, not from the occlusal position, nor the condylar position, because a relaxed position with no abnormal strain is the most appropriate position to use as “the stable mandibular position” for a person.
When the mandibular position is assessed, or when final prostheses are made and settled after proper adjustment of provisional restorations, or using an occlusal splint if a case needs it, the most important point is how to obtain a maxillomandibular relation which can be used to exactly reproduce a patient's current mandibular position. To register under force, even if it's just very weak force such as upper and lower teeth touching together very lightly, can easily spoil a stable mandibular position.
Although Lucia's Anterior Gig Method, Leaf Gauge Method and Gothic Arch Tracing Method are thought to be able to register a maxillomandibular relation without any force, actually they do make force and do affect the mandibular position. A large scale implement, such as a mandibular movement recorder, also absolutely affects the mandibular position, and is highly likely to spoil a stable mandibular position. To assess the mandibular position and to assess a mandibular movement is not the same thing, plus the purpose is different.
Considering all the aforementioned points, three different clinical cases; Crown-Bridge, Crown-Bridge with Temporomandibular Disorder and Complete Denture, which require occlusal reconstruction, are included to show how a mandibular position should be considered. Altered Chin Point Method was used to register the maxillomandibular relation, and Denar's Centric Relator and Vericheck Instrument were used for assessing the mandibular position with Split Cast Technique.
Assessing the mandibular position regularly as a part of normal, daily clinical procedure will lead to a healthy state of occlusion that will continue for a long time.
