Evaluation of mandibular arch width change.

The following conclusions can be drawn from this study and observations from the literature: The width of the mandible is influenced by intrinsic and extrinsic forces. Maximal opening, protrusion, and biting forces cause the mandible to decrease in arch width. A horizontal retruding force on the mandible for centric relation records caused an increase in arch width. The amount of mandibular arch width change during impression making can be minimized by preventing any protrusive movement and/or opening beyond 20 mm.