Clinical and magnetic resonance findings in the temporomandibular joints of patients before and after orthognathic surgery

It is difficult to achieve the correct position of the condyle in the tempo ral fossa during orthognathic surgery in angle class II patients with disor ders of the temporomandibular joint. This led us to examine the TMJ of 25 o f our own patients before and shortly after orthognathic operations. We recorded the clinical and magnetic resonance imaging findings of the tem poromandibular joint preoperatively and three months postoperatively. The p atients had skeletal class II dysgnathia and had been treated with fixed or thodontic appliances for a mean of two years and three months before operat ion. Operation resulted in a mean reduction of maximal incisor distance of 12 mm . In five of the 25 patients, the pattern of mouth-opening changed. Nine pa tients had less pain than before surgery, and nine had fewer abnormal joint sounds. The magnetic resonance imaging showed displacement of the articula r disc in 38 of the 50 joints preoperatively and in 28 postoperatively. Deg enerative joint changes were not improved by operation. Improvement of the disc position was achieved by repositioning of the condy lar-disc complex during orthognathic surgery in angle class II patients. Cl inical and magnetic resonance imaging findings regarding the temporomandibu lar joint in class II patients correlated significantly both preoperatively and postoperatively.