Nonunion in Orthognathic Surgery: A Case-Series of 15 Patients

Abstract

Bone nonunion is extensively studied in the orthopedic literature, but the knowledge in oral and maxillofacial surgery, specifically orthognathic surgery, is scarce. Since this complication has a significant negative impact on postoperative management of patients, more studies are needed. To report the characteristics of patients presenting with bone nonunion after orthognathic surgery. This is a retrospective case-series study on subjects who underwent orthognathic surgery between 2011 and 2021 and developed nonunion. Inclusion criteria were mobility at the site of the osteotomy and the need for a second surgical intervention. Exclusion criteria were an incomplete medical chart; the absence of nonunion upon surgical exploration, or radiological evidence of nonunion; cleft lip/palate; or syndromic patients. The outcome variable was bone healing after nonunion care. Demographics (age, sex), medical/dental comorbidities, type of surgery (type of fixation, bone grafts, Botox injection), amplitude of movements, nonunion treatment. Descriptive statistics were computed for each study variable. The sample was composed of 15 patients (11 females, mean age 40.4 years old) with nonunion (maxilla: 8 cases, mandible: 7 cases) out of 2036 patients who underwent orthognathic surgery during the period studied (incidence 0.74%). Nine (60%) were bruxers, three were smokers (20%) and one had diabetes. Mean forward movement of the maxilla was 6.55mm (4-9mm) and 7.71mm (4.8-12mm) for the mandible. All patients but one (who refused surgery) were treated by curettage of fibrous tissue and new hardware placement. In addition, 11 received a bone graft, and 4 had Botox injections. All osteotomies healed after the second surgical intervention. Curettage with or without grafting appears to be a good strategy for the cure of nonunion. Bruxism may be a risk factor (60% of patients were bruxers in this study).