Role of Custom-Made Prosthesis for Temporomandibular Joint Replacement in Unilateral Ankylosis - An Evaluative Study

Ankylosis is a physically and psychologically distressing condition to a patient. The aim of this study was to evaluate the efficiency of custom-made temporomandibular joint (TMJ) prosthesis (fossa-condyle component) in patients with unilateral ankylosis in restoring the form and functions of the TMJ.

This retrospective study was conducted in ten patients with unilateral TMJ ankylosis who had undergone TMJ reconstruction with custom-made TMJ prosthesis. Clinical parameters assessed were maximal mouth opening, lateral movements, improvement of the pain levels, and dietary efficiency of the patient. The data were analyzed using SPSS version 20 (IBM Corporation, SPSS Inc.; Chicago, IL, USA).

The mean preoperative mouth opening was 5.70 ± 3.62 mm. After gap arthroplasty, it was 32.50 ± 3.31 mm. The postoperative mouth opening after the reconstruction of TMJ using alloplastic joint prosthesis was 34.90 ± 2.69 mm, and after a mean follow-up period of 4 years, the mean postoperative mouth opening was 34.60 ± 2.50 mm. The mean preoperative movement toward the right and left side was 0.9 ± 1.2 mm and 1.3 ± 1.25 mm, respectively. The mean right and left lateral movements of the TMJ after reconstruction were 3.5 ± 0.97 mm and 3.70 ± 1.06 mm, respectively. There was decrease in deviation of the unaffected jaw during mouth opening and closure. Functional occlusion was maintained postoperatively. There was no appreciable change in the visual analog pain scales. The dietary efficiency improved from a scale of 10 (liquids) to a scale of 0 (no restriction to diet) in eight patients and 1 in two patients. The dietary score improved significantly after alloplastic reconstruction (P = 0.000). No evidence of facial nerve paralysis or foreign body reactions was noted in the patients during the follow-up period. Radiographic assessment revealed good positioning and adaptation of the fossa component and the condylar ramal component both postoperatively and after a mean 4-year follow-up period. There was no evidence of screw loosening or prosthesis breakage during the follow-up period.

The custom-made TMJ-total joint replacement (TJR) devices provide stable, improved long-term results, thereby increasing the quality of life of the patient. The custom-made alloplastic TMJ-TJR prosthesis proves to be the optimal surgical procedure to reconstruct the TMJ in comparison to the autogenous grafts (to avoid complications) in severe degenerated and ankylosed joints. However, long-term clinical and radiological studies on a larger sample size are imperative to establish the versatility of this procedure.