Comparison of bone adaptation after modification in biomet standard alloplastic temporomandibular joint prostheses

Purpose: The aim of the study was to compare bone adaptation after design modification in Biomet stock prostheses. Materials and methods: Computed tomography (CT) data of the patients treated with a Biomet TMJ replacement from 2010 to 2016 were recruited. Fossa prosthesis with a bulge and 4 types of condyle-ramus angle prostheses were virtually designed and implanted by computer-assisted simulation. The amount of bone trimming including fossa, mandibular ramus and bone graft were measured by ProPlan CMF 1.4 software. The differences between the original and modified prostheses were compared by SPSS 17.0 software for statistical analysis. Results: There were 54 patients’ CT data included in the study. The amount of fossa bone trimming was 150.20 mm ³ in the modified prosthesis and 281.82 mm ³ in the original one. The amount of ramus bone trimming was 103.86 mm ³ in the modified prosthesis and 229.45 mm ³ in the original one. The amount of fossa bone grafting was 95.88 mm ³ in the modified prosthesis and 263.03 mm ³ in the original one. There were significant differences between them (p = 0.000). Conclusions: The modified Biomet prostheses design requires less bone trimming and grafting for implantation.