Model surgery-guided interpositional arthroplasty with condylar prosthesis replacement for temporomandibular joint ankylosis: a preliminary single-center case series study

To explore the feasibility of model surgery-guided interpositional arthroplasty combined with condylar prosthesis as a complementary surgical option for temporomandibular joint ankylosis (TMJA), this study preliminarily evaluated its clinical outcomes. A retrospective case series of four consecutive TMJA patients (2020–2022). Both subjective and objective outcomes were assessed by comparing preoperative and postoperative measurements, including maximal interincisal opening (MIO), visual analog scale (VAS) scores for pain, diet, jaw function, and quality of life (QoL). Computed tomography was used to evaluate the status of the condylar prosthesis and the recontoured glenoid fossa, with documentation of any complications during the follow-up period. The mean follow-up duration was 4 years and 4 months, (minimum 3 years and 4 months). At the final follow-up, the mean MIO was increased to 35.0 mm from a preoperative mean of 7.25 mm. Reductions were observed in VAS scores for pain, diet, and jaw function, while QoL scores improved from “poor” to “excellent.” Imaging confirmed stable and well-centered positioning of all prostheses, with no evidence of screw loosening, prosthesis displacement/fracture, or heterotopic bone formation. Complications included one case of occasional paresthesia, which resolved with conservative management. In this small preliminary case series, the technique improved mouth opening, symptoms, and quality of life over 3 years, with no re-ankylosis. While short-term results are encouraging, historical concerns about long-term complications warrant caution. Larger, controlled studies with extended follow-up are needed.