Oroantral fistula after a zygomaticomaxillary complex fracture.

Zygomaticomaxillary complex (ZMC) fractures account for a substantial proportion of trauma cases. The most frequent complications of maxillofacial fracture treatment are infections and soft tissue flap dehiscence. Postoperative infections nearly always resolve in response to oral antibiotics and local wound care. However, a significant infection can cause a permanent fistula. A 52-year-old man visited our clinic to treat an oroantral fistula (OAF), which was a late complication of a ZMC fracture. Postoperatively, the oral suture site dehisced, exposing the absorbable plate. However, he did not seek treatment. After 5 years, an OAF formed with a 2.0× 2.0 cm bony defect on the left maxilla. We completely excised the OAF, harvested a piece of corticocancellous bone from the iliac crest, inserted the harvested bone into the defect, and covered the soft tissue defect with a buccal mucosal transposition flap. Although it is necessary to excise OAFs, the failure rate is higher for large OAFs (> 5 mm in diameter) because of the extensive defect in the underlying bone that supports the overlying flap. Inappropriate management of postoperative wounds after a ZMC fracture can lead to disastrous outcomes, as in this case. Therefore, proper postoperative treatment and follow-up are essential.