Evaluation and Prediction of Healing Morphology After Closed Reduction for Unilateral Mandibular Condyle Fractures

Although closed reduction is common for condylar fractures, bone fragments may heal improperly. This study aimed to investigate the healing morphology of unilateral condylar fractures. We retrospectively investigated 70 patients with unilateral condylar fractures. Clinico-statistical analyses were performed on the whole-condylar fracture, closed reduction, and observation/functional therapy groups. Among these patients, 52 patients aged older than 16 years underwent closed reduction. The extent of maximum mouth opening, the incidence of malocclusion, and the relationship between healing morphology and Arbeitsgemeinschaft für Osteosynthesefragen classification or trismus were analyzed in the closed reduction group. There were significant differences in age ( P= 0.008) and sex ( P =0.025) between the closed reduction and observation/functional therapy groups. However, there were no significant differences in trauma etiologies and concomitant fractures between the 2 groups. The average maximum mouth opening extent for unilateral fractures after closed reduction was 42.6±6.1 mm. Only 1 case (2.1%) of post-treatment malocclusion was observed. In all the MacLennan classification of deviation or more, regardless of the classification, upper fractures (head and upper neck) tended to heal through a spherical ( P <0.001) morphology, whereas lower fractures (lower neck and subcondylar) tended to heal through an L-shaped and lateral fusion ( P <0.001). There was no significant difference in the incidence of trismus between the healing morphology of unchanged type and others ( P =0.690). Our results elucidated the etiology, dysfunction, and healing morphology classification of unilateral mandibular condyle fractures treated with closed reduction.