Worsening of pre-existing TMJ dysfunction following sagittal split osteotomy: a study of three cases

When patients seeking treatment for malocclusion also suffer from temporomandibular joint (TMJ) disorders, it is hard to predict the result of simultaneous treatment of both conditions, or to plan for its different goals, because of unpredictable changes in the relationship between the disk, the fossa and the condylar head. Prediction is harder in cases of presurgical TMJ hypomobility, especially those with adhesion in the upper TMJ compartment. Authors differ widely on the likely effect of orthognathic surgery on TMJ disorders. This paper reports three cases in which TMJ disorders worsened after treatment of malocclusion by sagittal split osteotomy. It examines how presurgical diagnosis of TMJ disorders could assist treatment planning in such cases. The results suggest that microbleeding in the upper TMJ compartment during orthognathic surgery, as well as long-term postoperative intermaxillary fixation, carries a risk of creating worse adhesion that adversely affects the outcome for patients. Therefore, preoperative diagnosis of disk position and pathological conditions in the upper TMJ compartment, as well as careful choice of method and term of postoperative fixation, are essential in planning the treatment of malocclusion with sagittal split osteotomy.