Histologic and tomographic analyses of the temporomandibular joint after mandibular advancement surgery: study in minipigs

Objective The aim was to elucidate the changes occurring in temporomandibular joint (TMJ) after surgical mandibular advancement with different fixation materials: bicortical screws and miniplates. Study design Eighteen minipigs were randomly divided into 3 groups: group I (control), nonoperated animals; group II, animals submitted to surgical advancement surgery and osteosynthesis by bicortical screws; and group III, animals submitted to surgical advancement surgery and osteosynthesis by miniplates. Four months after the surgeries, TMJs were collected and histologically prepared after computerized tomography (CT) scanning for the blind detection of erosion, flattening, and osteophyte. Results The CT analysis revealed significant alterations in the shape of the condyles (erosion: P = .0010; flattening: P < .0001) for group II compared with groups I and III. Descriptive histologic analysis was compatible with the CT findings. Conclusions The results indicated that bicortical screw fixation resulted in more pronounced condylar alterations in the shape of the condyles than miniplate osteosynthesis. However, further clinical studies are necessary to confirm these data.