Two Cases of skeletal Class II Malocclusions with Severe Osteoarthrosis of TMJs treated by Orthognathic Surgery

In orthognathic surgery cases, where patients have facial deformities and temporomandibular diseases, like osteoarthritis, exacerbation of the disease after surgery may occur. Therefore, the timing and procedures of the surgery need to be well managed, as well as the control of the occlusion after the operation. We report two cases with maxillary protrusion and mandibular retrognathism combined with severe osteoarthrosis of the temporomandibular joint (TMJ). The patients underwent surgical orthodontic treatment, where the maxilla was impacted and the mandible replaced forwardly. After the surgery, we placed a bone screw at the alveolar bone for the longterm use of intraoral elastics as a fixing to prevent skeletal relapse, and achieved a good functional occlusion and good esthetic results. We consider that the result of these treatments shows the effectiveness of the bone screw for preventing skeletal relapse after operation. Our first case was afemale patient of 18 years old, who reported that at the age of 9, she had received orthodontic treatment due to crowding of theteeth and ended the active treatment when she was 12 years old. She came to our office with an open bite and a posterior mandible placement, which became evident to her a year earlier. In the second case, a 20-year-old female patient reported that at the age of 10 she had clicking at both TMJs, frequently could not open her mouth and often had pain at the TMJ, but she had not sought treatment at that time. The patient came to us citing posterior mandibular placement as her chief complaint. The first case showed clicking at the maximum mouth opening and the second case showed clicking during both the opening and closing of the mouth, without finding the opening difficulties of the mouth that she had had before. Although X-ray and CT images revealed for both cases a severe condylar resorption, the cortical bone was present, with no evidence found by Tc scintigraphy of the TMJ. Both patients received orthodontic treatment prior to surgery, with impaction of the maxilla and forward replacement of the mandible. The bone screw remained for 12 months for the first case and for 7 months for the second case. Although both the facial appearance and the occlusion achieved are good and both have asymptomatic TMJs, the second case showed slight worsening of the condylar deformation after removal of the bone screw.