Purpose: Bone defects of the inferior mandibular border (osseous inferior border defects) can cause unesthetic postoperative outcomes after bilateral sagittal split osteotomy (BSSO). The aim of... Show morePurpose: Bone defects of the inferior mandibular border (osseous inferior border defects) can cause unesthetic postoperative outcomes after bilateral sagittal split osteotomy (BSSO). The aim of this study was to estimate the frequency of osseous inferior border defects after BSSO and to identify risk factors for this complication.Materials and methods: This retrospective study included consecutive patients who underwent BSSO for mandibular retrognathia. The primary outcome was the presence/absence of osseous inferior border defects. Predictors included the mandibular movement, rotation of the occlusal plane, postoperative proximal segment position, pattern of lingual fracture, occurrence of bad split, and presence of third molars.Results: The study sample consisted of 200 patients and had a mean follow-up of 13 months. The mean mandibular advancement and rotation was respectively 5.8 mm and 5.4 degrees clockwise. Osseous inferior border defects were present in 7.0% of splits and in 12.5% of patients. Significant risk factors for inferior border defects included increased advancement, increased clockwise rotation, cranial rotation of the proximal segment, and a split originating in the lingual cortex.Conclusion: In conclusion, osseous inferior border defects occur significantly more often in cases with large mandibular advancement, increased clockwise rotation of the occlusal plane, malpositioning of the proximal segment, and a split originating in the lingual cortex. (C) 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. Show less
Verweij, J.P.; Hassing, G.J.M.; Fiocco, M.; Houppermans, P.N.W.J.; Merkesteyn, J.P.R. van 2016
Bilateral sagittal split osteotomy (BSSO) is a widely used orthognathic surgery technique. This prospective observational study investigated the correspondence between the planned inferior border... Show moreBilateral sagittal split osteotomy (BSSO) is a widely used orthognathic surgery technique. This prospective observational study investigated the correspondence between the planned inferior border cut and the actually executed inferior border cut during BSSO. The influence of the inferior border cut on lingual fracture patterns was also analyzed.Postoperative cone beam computed tomography (CBCT) scans of 41 patients, representing 82 sagittal split osteotomies, were investigated. The inferior border cut was intended to penetrate completely through the caudal cortex. Descriptive statistics were used to analyze the executed inferior border cuts. Mixed models were used to investigate the influence of independent variables such as the surgeon's experience on the inferior border cut. Secondarily the influence of the inferior border cut on lingual fracture patterns and the incidence of bad splits was assessed.The inferior border cut reached the caudal cortex in all cases, but reached the lingual cortex in only 38% of the splits. There was no significant relationship between the inferior border cut and a specific lingual fracture line.In this study, postoperative CBCT analysis revealed that the bone cuts during BSSO were often not placed exactly as planned. No significant relationship between the inferior border cut and lingual fracture patterns or bad splits was, however, detected. (C) 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved. Show less
Verweij, J.P.; Mensink, G.; Fiocco, M.; Merkesteyn, J.P.R. van 2015
The goal of this thesis is to prove the safety and predictability of BSSO by the splitter__ separator technique in an extensive study of its possible major sequelae. The revised BSSO technique will... Show moreThe goal of this thesis is to prove the safety and predictability of BSSO by the splitter__ separator technique in an extensive study of its possible major sequelae. The revised BSSO technique will be assessed by the following means: 1. Reviewing both BSSO techniques and their incidences of postoperative NSD of the IAN (chapter 2) 2. Analyzing fracture patterns in cadaveric mandibles (chapters 5 and 6) 3. Measuring postoperative hypoesthesia of the IAN in a prospective study (chapter 3) 4. Examining stability during adolescence (chapter 4) 5. Examining bad splits in a retrospective study (chapter 7) 6. Reviewing specific applications (chapters 8 and 9). Show less
