The TMJ dysfunction syndrome before and after sagittal split osteotomy of the rami

280 patients with different types of mandibular deformities (prognathism, retrognathia, open bite, asymmetry) had been operated on by sagittal split osteotomy of the rami. The patients, routinely checked preoperatively, were found to present subjective or objective TMJ dysfunction symptoms with an incidence of 40.8%. After surgery the incidence of such symptoms in the same patients was 11.1%. The patients with no TMJ dysfunction symptoms preoperatively, presented such symptoms with an incidence of 3.7% postoperatively, a percentage very low in comparison with other statistics.