Sagittal Splitting of the Mandibular Ramus: Electromyography and Radiologic Follow-up Study of Temporomandibular Joint Function in 44 Patients

Abstract

A follow-up study was performed on 44 patients operated with sagittal splitting of the mandibular ramus for correction of a mandibular protrusion. The study included clinical examination, electromyography and masticatory efficiency test as well as radiography of the temporomandibular joint. The maximum opening capacity and protrusion of the mandible decreased one to three years after the operation. The activity of the temporal muscle decreased in rest position after the operation. Masticatory efficiency was unchanged. The position of the condyle in the fossa was unchanged postoperatively, while a posterior and superior condylar movement occurred during the fixation period. Normalization of the condylar position tended to occur one year after the operation. In 37 of 86 condyles, a double contour was seen on the posterosuperior margin of the condyle one year after the operation. Possible mechanism behind the development of the new condylar bone layer is discussed.