“Bad” splits of mandible during orthognathic surgery. Experience of clinic of esthetic surgery

Introduction. “Bad” fracture of the mandible is a condition that occurs during sagittal osteotomy of the mandible. There are enough possible factors predisposing to this condition, however, there is no clear evidence for any of them. Difficulties are possible in the presence of impacted third molars, anatomical features of the ramus, excessive force during osteotomy, and so on. The main types of uncontrolled fractures are fracture of the proximal segment, fracture of the distal segment, coronoid process, and condylar process.
Aim. To analyze medical records of patients who underwent sagittal osteotomy of the mandible and to identify possible predisposing factors for the occurrence of “bad” fractures.
Material and methods. We analyzed the medical records of 108 patients who underwent sagittal osteotomy of the mandible. Nine patients had “bad” fractures of the lower jaw; in three cases, the fracture was bilateral. All patients were women, and the mean age was 36±7 years. 7 patients had distal occlusion. Only 1 case represented a removal of an impacted 3rd molar. All patients underwent metal synthesis of the “bad” fracture line using a rectangular frame and 4 titanium screws for more rigid fixation of the fragments, and the synthesis of the proximal and distal segments was performed with a linear titanium plate.
Results. According to the data obtained, we have not identified a clear relationship between any of the known predisposing factors and the occurrence of an uncontrolled fracture. With sagittal osteotomy, an “uncompleted” fracture may occur, which differs from the planned line, but does not require correction of treatment tactics.
Discussion. Among maxillofacial surgeons, there is no clear opinion about the predisposing factors for the occurrence of “bad” fractures of the mandible. Depending on the sample design, various authors obtain controversial results. Thus, our study did not obtain reliable data on an increase in the risk of uncontrolled fracture depending on gender, age, the presence of a third molar, or the instruments used.
Conclusions. According to the results obtained, there is no correlation between the risk of a “bad” fracture of the mandible and any of the well-known factors. Despite this, uncontrolled fractures occurred more often in patients with distal occlusion. A good method for osteosynthesis of such a fracture line is a rectangular plate. Key words: bad split, sagittal osteotomy of mandible, orthognathic surgery
Conflicts of interest. The authors have no conflicts of interest to declare. Funding. There was no funding for this study