Application of fossa bone graft to stabilize stock total joint prosthesis in temporomandibular joint surgery.

PURPOSE: To describe a new glenoid fossa bone graft technique, and to evaluate its effect on the stability of stock fossa prosthesis implantation in total alloplastic joint replacement surgery.

METHODS: Eight patients who underwent total joint replacement surgery with a Biomet stock prosthesis (Biomet, Warsaw, IN, USA) from November 2013 to April 2014 were included in this study. ProPlan CMF 1.4 software (Materialise NV, Leuven, Belgium) was used to choose the prosthesis size and place it in the right position. The depth of the fossa was measured, and the osteotomy line was designed to cut the bone which overlapped the fossa prosthesis. A bone graft, taken from the bottom of the articular eminence or the condylar neck, was used to fill in the fossa and make a flat plane in combination with the residual eminence for the positioning of the fossa prosthesis. The stability of the fossa prosthesis was evaluated both intra-operatively and postoperatively with computed tomography (CT) scanning after at least 6 months of follow-up. The bone contact area of the fossa prosthesis and the volume of the grafted bone were measured.

RESULTS: Fossa prostheses were intra-operatively stable after bone grafting. All patients had stable occlusion after surgery and at follow-up. Postoperative measurement showed that the bone contact area with the fossa prosthesis increased from 52.8% to 88.5% after bone grafting. Postoperative CT measurements (at an average of 9 months after surgery) showed that the bone graft volume decreased by 11.1%.

CONCLUSION: Bone grafts in the glenoid fossa help to improve the stability of Biomet stock fossa prosthesis implantation.