CONDYLAR REPOSITIONING BY MEANS OF A NEW DEVICE IN TMJ DYSFUNCTIONAL PATIENTS

Introduction: Many devices have been proposed for preserving the preoperative position of the mandibular condyle during bilateral sagittal split osteotomy. Accurate mandibular condyle repositioning is considered important to obtain a stable skeletal and occlusal result, and to prevent an impairment of previous temporomandibular disorders (TMD). Objective: This study is a preliminary report concerning the use of a new condylar positioning device (Medicon, Tuttlingen, Germany) in a group of 5 dysfunctional TMJ patients with the aim of maintaining the preoperative position of the condyle during orthognathic surgery. Methods: Five TMJ dysfunctional patient underwent a bimaxillary surgery for dento-scheletal malocclusion. Fabrication of preoperative positioning wax bite was done according to an optimized proximal segment position as assessed in clinical examination, through stabilization splints and TMJ cone beam tomography study. The positioning wax bite was set in occlusion, fixed by intermaxillary wires, and positioning plates were adapted on the anterior mandibular ramus thorough an intraoral approach in female patients, while a transcutaneous via(trocar device) is chosen in male patients. The plates are connected with removable extraoral articulated arms to a modified cranio-facial bow, fixed on temporal/parietal bones by means of transcutaneous pins. The articulated joints of the arms are locked, allowing the registration of optimized proximal segment position in accordance of the preoperative wax bite. Bimaxillary surgery was then performed according to the planning. Before mandibular fixation with 2 rigid titanium plate on each side, the articulated locked arms are repositioned and connected to positioning plates. Mandibular fixation is then completed. The articulated arms and the positioning plates are removed. The dental and skeletal stability, signs and symptoms of TMD, the comparison of preoperative and post-operative TMJ cone beam tomography are evaluated during the follow-up period. Questions: 1 - Anterior distraction of the condyle from the fossa during orthognatic surgery produces: a) Immediate skeletal relapse b) Spontaneous and uneventful occlusal stabilization c) Condylar resorption d) All of the above 2-Late skeletal relapse is likely attributable to: a) Muscle memory b) Proximal segment rotation and posterior repositioning of the condyle c) Any mandibular advancement d) None of the above 3-Condylar positioning devices in mandibular orthognathic are: a) Often used in orthognathic surgery b) Barely used while manual repositioning is preferred c) All of the above d) None of the above 4-TMJ dysfunctional patients that underwent orthognathic surgery with rigid fixation: a) Always report a worsening on TMJ sign and symptoms after surgery b) Can achieve an improving in pain and functional status after surgery c) All of the above d) None of the above