Limitations of osseous genioplasty in relation to the displacement distance: a computer-based comparative study.

[OBJECTIVE] The aim of this study was to compare the contact surface area (CSA) between bony segments after performing 4 different osteotomy techniques for genioplasty.

[STUDY DESIGN] Virtual genioplasties were done in terms of sliding or chin-shield genioplasty and 1- or 2-tiered genioplasty on computed tomography (CT) data from 42 patients. Advancement or setback genioplasty was simulated at 3, 5, 8, and 10 mm. The resulting bony contact areas were calculated by using software.

[RESULTS] No statistically differences were found between both 2-tiered techniques at any displacement distance. Significant statistical differences were noticed between 1-tiered genioplasty and corresponding upper and lower osteotomy at 2-tiered genioplasty and between lower osteotomies of both 2-tiered techniques (P < .001). However, at a displacement distance of 8 mm, the CSA of the lower 2-tiered genioplasty was found to be larger than that of the corresponding after 1-tiered genioplasty (P < .001).

[CONCLUSIONS] From a displacement distance of 8 mm, a relatively larger CSA could be achieved after performing 2-tiered genioplasty technique.