Computer-assisted surgical planning and simulation for unilateral condylar benign lesions causing facial asymmetry

Abstract

The purpose of this study was to investigate the best surgical sequence for the treatment of unilateral condylar benign lesions causing facial asymmetry by applying computer-assisted surgical planning and simulation. Computed tomography (CT) data from 12 patients whose maxillary cant was corrected by maintaining the vertical position of the central incisors and equally intruding the long side of the maxilla and extruding the short side were analyzed by ProPlan CMF 1.4 software (Materialise Medical, Leuven, Belgium). Condylectomy and double jaw orthognathic surgery with 2 different surgical sequences were simulated: 1) maxillary LeFort I osteotomy first (MaxF), then condylectomy, followed by bilateral sagittal split ramus osteotomy (BSSO); and 2) mandible first (ManF), beginning with condylectomy, then BSSO, and lastly LeFort I osteotomy. The greatest space between the maxillary and mandibular first molar in the interim positions was measured virtually to compare the 2 surgical sequences. The vertical distance between the upper and lower teeth of ManF patients was significantly smaller than that of MaxF patients (mean 2.99mm, P<.001). When occlusal cants are corrected by equally intruding one side and extruding the other side of the maxillary dentition, the interim position is more conducive to sequencing corrective surgery by performing condylectomy, then BSSO, followed by Le Fort I osteotomy.