Ciftci, SezaiCetiner, YunusOzden, Samet2026-04-042026-04-0420260972-82790974-942Xhttps://doi.org/10.1007/s12663-026-02996-9https://hdl.handle.net/11616/109761Purpose To assess the effectiveness of various surgical techniques for repairing oronasal fistulas (ONFs) and to present clinical cases utilizing multilayer closure and tongue flap combinations. Materials Four ONF patients underwent different repairs: three-layer closure for an orthodontic appliance-induced fistula, double palatal flap with buccal fat pad for a congenital fistula, anteriorly based tongue flap for a recurrent fistula, and autogenous bone grafting with flap reconstruction for dual fistulas. Results Complete closure was achieved in three patients (75%), with one small asymptomatic residual fistula. No major complications were observed during 6-12 months of follow-up. The appliance-induced fistula appears to be the first reported case linked directly to orthodontic devices. Conclusion ONF repair remains complex, with outcomes influenced by defect size and tissue quality. Local flaps are adequate for small defects, whereas larger or recurrent cases benefit from advanced reconstructive methods. Long-term orthodontic appliance use may increase fistula risk, highlighting the need for close monitoring.eninfo:eu-repo/semantics/closedAccessOronasal fistulaSurgical repairCase seriesOrthodontic applianceTongue flapBuccal fat padArticle10.1007/s12663-026-02996-9WOS:001714682400001Q4