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

Abstract

Background: 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.

Purpose: To report the characteristics of patients presenting with bone nonunion after orthognathic surgery.

Study design, setting, sample: 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.

Main outcome variable: The outcome variable was bone healing after nonunion care.

Covariates: Demographics (age, sex), medical/dental comorbidities, type of surgery (type of fixation, bone grafts, Botox injection), amplitude of movements, nonunion treatment.

Analyses: Descriptive statistics were computed for each study variable.

Results: 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 6.55 mm (4-9 mm) and 7.71 mm (4.8-12 mm) 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.

Conclusion: 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).