Comparative efficacy of patient-specific and stock implants in temporomandibular joint replacement: a systematic review and meta-analysis.

Evidence for the superiority of patient-specific implants (PSI) over stock implants in temporomandibular joint (TMJ) replacement remains inconclusive. The objective of this study was to provide guidance for clinical decisions by evaluating whether PSI offer advantages over stock systems in rehabilitation of the TMJ. A systematic search was performed in three databases to identify studies reporting mouth opening, pain, and diet outcomes for PSI and/or stock TMJ implants. Two-arm studies were analysed separately from pooled single- and two-arm studies; studies with comparable follow-up times were compared. Forty-two observational studies involving 2221 patients were included. PSI showed a consistent trend towards greater mouth opening across most follow-up times; however, a significant difference in favour of PSI was only observed in two-arm studies at >12 months (mean difference 5.83 mm; P = 0.025). Pain outcomes were mixed: stock implants favored early pain and late diet change, while PSI favored pain relief at 6-24 months. The findings suggest PSI should be considered for movement restrictions, while stock implants may provide an alternative for pain and dietary needs. Due to the observational nature of the included studies and differences in study populations across arms, the findings should be interpreted with caution.