Occurrence of bad splits during sagittal split osteotomy

Objectives The objectives of this study were to determine the incidence of bad splits in sagittal split osteotomies (SSOs), performed at the same hospital, and if the occurrence was reduced over time because of technical progress and/or surgical experience. Bad splits were defined as buccal or lingual plate fractures. Study design The files of all patients (n = 1008) who underwent bilateral or unilateral SSO between October 1989 and October 2009 were reviewed retrospectively. Results A bad split occurred in 14 SSO sites (14 of 2005 sites). No bilateral bad splits occurred. There was no notable decrease of bad splits over the 20 years. All bad splits were resolved perioperatively by plate-osteosynthesis without the additional need of intermaxillary fixation. All patients with a bad split had a good and functional occlusion 6 months postoperatively. No infections occurred at the site of the bad splits. No bad splits occurred in patients younger than 20 years. No particular type of dental-facial deformity, or skeletal class according to the Angle's classification could be correlated with cases of bad splits as a predisposing risk factor. Conclusion Even if precautions are taken, a bad split can occur during SSO of the mandible. This complication is manageable because of its low incidence (0.7 % of all SSOs) and uneventful healing. A significant decrease in incidence did not occur during the 20-year period, and neither technical progress nor the surgeon's experience further reduced the incidence of bad splits.