Prevalence, Morphology, and Risk Factors of Mandibular Ramus Fractures: A Retrospective Cohort Study
Stefan Krennmair, Simon Kienberger, Matthias Angerer, Lukas Postl, Gerald Krennmair, Michael MalekABSTRACT
Objectives
Because mandibular ramus fractures represent a rare entity among the various fracture patterns of the mandible, the present study evaluated the prevalence, morphology, and risk factors associated with mandibular ramus fractures.
Material and Methods
The prevalence of mandibular ramus fractures was evaluated in patients diagnosed with mandibular fractures over 5 years. Along with epidemiologic data, fracture morphology, treatment modalities, and patient‐related risk factors, such as gonial angle and third molar impaction, were assessed for the ramus fractures and compared with angle fractures.
Results
Out of 547 patients diagnosed with mandibular fractures, 15 (2.7%; 10 m/5 f) presented with ramus fractures. Patients with mandibular ramus fractures demonstrated a significantly higher rate of female patients (33.3% vs. 9.6%, p = 0.021) and multiple fracture patterns (66% vs. 40.9%, p = 0.042; OR 2.91) compared to those with angle fractures (115/547; 21%; 104 m/11 f). Regarding fracture morphology, 12/15 (80%) ramus fractures exhibited a vertical/oblique fracture line, while comminuted fractures were observed only in 3/15 (20%) patients. Road traffic accidents (RTAs) were the predominant etiology for ramus fractures (46.6%, p < 0.025) and served as a potent predictor for complex multiple fractures (OR = 6.48, p < 0.001). Although deeply impacted third molars were significantly less frequent in ramus fractures than in angle fractures (13.3% vs. 38.3%; p = 0.049), the mean gonial angle was wider in the ramus group (130.3° ± 7.2° vs. 127.4° ± 6.2°, p = 0.098). In contrast to maxilla–mandibular fixation (13.3%), open reduction and internal fixation (ORIF) was the primary treatment modality (86.4%, p < 0.01); both yielded a high success rate without severe complications.
Conclusion
A high gonial angle and the absence of deep third molar impaction structurally predispose the mandibular ramus to injury, particularly acting as predictors for complex fracture patterns during road traffic accidents (RTAs).