The Influence of the Mandibular Gonial Angle on the Incidence of Mandibular Angle Fracture—A Radiomorphometric Study

Abstract

The aim of this radiomorphometric study was to analyze the association between the mandibular gonial angle and the risk of mandibular angle fracture. A retrospective analysis of medical records and radiographs of patients treated for mandibular fractures was performed. The exposure studied was the presence of a high gonial angle and the outcome was fracture of the mandibular angle. The mandibular gonial angle and mandibular height at the angle were measured using Facad software (Ilexis AB, Linköping, Sweden). Data obtained were analyzed using SPSS 16 (IBM Corp, Armonk, NY). The study sample was comprised of 210 mandibular fractures (70 mandibular angle fractures and 140 non-angle fractures). The mean gonial angle in patients with mandibular angle fractures was 126.8 ± 7.9°, which was 4.5° larger than in patients with other mandibular fractures (P= .0001). Patients with a high gonial angle were 11.77 times more likely to sustain an angle fracture than those with normal or low gonial angles (adjusted odds ratio= 11.77; 95% confidence interval, 3.65-37.94; P < .001). There also was a statistically significant decrease in mandibular height at the angle in patients with a high gonial angle (P= .0001). This study shows that people with a high gonial angle are at an increased risk for angle fracture and presents the related clinical implications.