Three-dimensional Spatiotemporal Analysis of Condylar Remodeling After Conservative Treatment of Pediatric Mandibular Condylar Sagittal Fractures

Objective This study investigated condylar remodeling and the role of the temporomandibular joint (TMJ) disc in growing patients with sagittal fractures of the mandibular condyle (SFMC) treated conservatively. Materials and methods A retrospective analysis was performed on 28 children (aged 4–12 years) with 43 SFMCs using three-dimensional models reconstructed from computed tomography (CT) and magnetic resonance imaging (MRI) obtained before treatment and at 3, 6, and 12 months after treatment. To evaluate condylar remodeling and its relationship with the articular disc, multimodal image registration was applied to fuse CT and MRI datasets. Results The results demonstrated a significant decrease in condylar volume from pre-treatment to 3 months post-treatment (Phase P1, P = 0.006). No significant change was observed between 3 and 6 months (Phase P2, P = 0.977), followed by a significant increase from 6 months to 1 year (Phase P3, P = 0.005). Bone formation predominantly occurred in regions covered by the articular disc, with significant differences in root mean square (RMS) values between disc-covered and non-disc-covered areas (P = 0.012). Conclusions These findings indicate that condylar remodeling is most active during the first 3 months following conservative treatment of pediatric SFMC and that the TMJ disc plays a critical role in this process. Clinical relevance: Clinical prognostic studies on sagittal condylar fractures in children can assist clinicians in more accurately assessing fracture severity, selecting the most appropriate treatment strategies, reducing the incidence of complications, and ultimately improving overall treatment outcomes in pediatric patients.