Clinical evaluation of temporomandibular joint disorder after orthognathic surgery in skeletal class II malocclusion patients

Objectives: This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion.Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010.They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement.The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement.The minimum follow-up period, including orthodontic treatment, was 12 months.Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients).The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation.Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from 34.5±2.1 mm to 37.2±3.5 mm.The differences were not statistically significant, however.Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI.Conclusion: No particular improvements were found in patients with joint sound only.Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).