Triple-Layered Closure Of An Oroantral Fistula: A Case Report

Introduction: An oroantral fistula (OAF) is an abnormal connection between the oral cavity and the maxillary sinus, usually occurred after the removal of maxillary premolar and molar teeth. Many techniques have been described for closure of oroantral fistulas but ignoring restoration of bony defects secondary to OAFs. This report presents a novel three-layered method for repairing OAFs with biomaterials sandwiched between the maxillary sinus floor mucosa and the palatal flap. Case description: A 59-year-old female patient was admitted to clinic with an oroantral fistula, of which the diameter was 6 mm. Firstly, peripheral soft tissue of the fistula was utilized to repair the maxillary sinus floor mucosa. And then, a mineralized collagen plug was placed over the sinus mucosa. Finally, the fistula was completely covered by a palatal flap. The follow-up period lasted for 6 months to evaluate the closure of the OAF and bone regeneration. Discussion: To yield adequate bone, a mineralized collagen plug was used to maintain space and promote bone generation. Compared with a buccal flap, a pedicled palatal flap has advantages of offering well-keratinized gingiva, not reducing the ridge height and better blood supply, thus ensuring success of both the closure of OAFs and the subsequent implant placement. Conclusion/clinical significance: The closure was successfully achieved without any signs of inflammation in the maxillary sinus and regenerative bone was observed after 6 months. The triple-layered technique is an effective procedure to repair OAFs.