Healing of fractures of the neck of the mandible in rats with detachment of the lateral pterygoid muscle

Abstract

The healing of unsplinted subcondylar fractures after detachment of the lateral pterygoid muscle is described in nearly adult female rats. The operations, undertaken unilaterally, resulted in a nearly normal re-aligned mandible, a complete reformation of the periosteum and a complete reattachment of the lateral pterygoid muscle 8 weeks after operation. Functionally the procedure resulted in minimal impairment in mastication, and then essentially only in the first two weeks after operation. An unusual observation was the appearance of a tongue of fibrous tissue containing a vein which entered the superior joint cavity. The operated side did show some reduction in condyle size and ramus height, the latter appeared to have led to a compensatory deposition of bone on the articular surface of the squamosal bone. The overall results indicate that this procedure gives a satisfactory result which appeared superior (as judged by the consistently favourable alignment of the fracture) to such operation without detachment of the lateral pterygoid muscle.