Condylar positions before and after bilateral mandibular distraction osteogenesis in children with Pierre Robin sequence.

This study aimed to analyze the changes in mandibular morphology after bilateral mandibular distraction osteogenesis (BMDO) in children with Pierre Robin sequence. The positions of the condyles were analyzed in reconstructed three-dimensional craniomaxillofacial images obtained for 18 children before and 8-12 weeks after BMDO. Differences between pre- and postoperative parameters were assessed using paired t-tests. After surgery, a significant decrease in superior joint space was detected (P<0.05), but no change in anterior joint space or posterior joint space was observed. The ratio of the distance between gonia and distance between condylion points (GoL-GoR/CoL-CoR) (P<0.001) and the distances between the condyle and midsagittal plane (P<0.001) increased after surgery, while the condylar horizontal angle decreased (P<0.05). No change in condylar vertical angle was noted. After BMDO, the condyle displayed an outward and upward shift, as well as outward rotation along the proximal segment. The mandible body exhibited forward movement with a more significant opening range. These changes were consistent with the extent of the newly formed bone tissue and the improvement in coordination and appearance of the children's facial structures. The long-term effects of changes in condylar position on the development of the maxillofacial structures needs to be studied further.