In a patient who undergoes an intraoral vertical ramus osteotomy (IVRO) and relapses after release of intermaxillary fixation, what is a common cause?

Intraoral vertical ramus osteotomy (IVRO) is a surgical procedure often performed to correct mandibular deformities or to adjust occlusion. A common concern after this procedure is relapse, particularly when the intermaxillary fixation is released.

When the condyle is not properly seated in the glenoid fossa during the surgical procedure, this can lead to instability in the occlusion after the fixation is removed. If the condyle is not positioned correctly, this can prevent optimal healing and could result in the condyle not maintaining its new position postoperatively. Proper seating is critical not only for immediate postoperative stability but also for the long-term outcomes of the osteotomy.

Inadequate seating can allow the mandible to return partially to its original position or cause altered relationships between the dental occlusion, leading to complications and potential relapse. This emphasizes the importance of precise surgical technique and positioning during the procedure.

While other causes can contribute to relapse, such as excessive bone resorption, improper fixation, or malunion at the osteotomy site, the specific factor of not seating the condyle deals directly with the functional positioning of the jaw and is a more immediate concern following the release of intermaxillary fixation. Understanding this can help in improving surgical