Mandibular movement during autorotation as a result of maxillary impaction surgery.

With increasing use of maxillary surgery to reduce vertical dimension, it would be appropriate to evaluate methods of predicting autorotation of the mandible. Experimental data derived from edentulous patients using metallic implants embedded in occlusal wax rims matched geometrically analyzed clinical data accumulated from twenty-three patients treated by maxillary impaction procedures. The center of rotation of mandibular autorotation during maxillary surgical impaction has been represented in the literature as the center of the condyle. Our evidence with lateral head films taken in centric occlusion supports a different instantaneous center of rotation located within the mastoid region. Modification of prediction tracing techniques by orthodontists and oral surgeons engaged in maxillary surgery could be indicated.