It is sometimes difficult to coordinate arches when aligning the teeth in Class III surgery. In Class II surgical cases, the patient can be asked to protrude the mandible to check arch coordination.
Since this is not possible in Class III cases, here is a simple trick to help.
First, take a snap impression of the mandibular arch, and pour a model in Fast-Set plaster or stone (Fig. 1). Next, trim off excess base material so all that remains of the model is a small index of the occlusal surfaces of the mandibular teeth (Fig. 2). Finally, insert the index into the mouth to check for arch coordination (Fig. 3).
Using this procedure, the arches can be closely coordinated so that, once the surgery is performed, the arches should match well and the orthodontic finishing can be completed quickly.
Thanks to Dr. Van Speas of Fort Meyers, Florida, for contributing this Pearl. If you have a Pearl to share with your colleagues, send it to Dr. Jerry Clark, 1115 W. Friendly Avenue, Greensboro, NC 27401.
