CONDYLAR RESORPTION AFTER BICORTICAL SCREW FIXATION OF MANDIBULAR ADVANCEMENT

Purpose: This study evaluated long-term condylar resorption after mand ibular advancements stabilized with bicortical screws. Patients and Me thods: One hundred mandibular deficiency patients who underwent bilate ral sagittal split osteotomies (BSSO) fixed with three bicortical scre ws per side, and who were followed for a minimum of 1 year with comple te radiographic records, were evaluated. Preoperative panoramic radiog raphs were traced and superimposed as a best fit over long-term panora mic radiographs. Cephalometric tracings were available on all patients preoperatively, immediately after surgery, 6 to 8 weeks after surgery , and at long term after surgery. These tracings were used to show the amount of the initial advancement and any changes that occurred betwe en 6 to 8 weeks and long term in those patients who exhibited 10% or g reater changes in their condylar height. Preoperative temporomandibula r joint signs and symptoms were recorded on all patients before surger y and at 6 months after surgery. Results: There were 10 patients who h ad 10% or greater vertical change in their condyles; all changes were unilateral. Large advancement (P>.009) and preoperative temporomandibu lar joint symptoms (P>.01) statistically correlated with long-term pos toperative condylar resorption, There was not a direct correlation bet ween the amount of vertical change in the condyle and the amount of re lapse. There was an improvement in temporomandibular joint symptoms fo r the group as a whole and in the group with condylar resorption. Conc lusions: Patients with large advancements and preoperative temporomand ibular joint symptoms appear to be at risk for condylar resorption. Th ese results are similar to those from other studies in which rigid fix ation or miniplates were used for cases of mandibular advancement.