By reviewing the literature, we can conclude that in selecting the surgical approach to close an oroantral fistula, different parameters have to be taken into account, including location and size of fistula as well as its relationship to the adjacent teeth, height of the alveolar ridge, persistence, sinus inflammation and the general health of the patient.

A small oroantral fistula of less than 5 mm in diameter can be closed immediately and effectively by suturing the gingiva with a figure eight suture. If this does not provide adequate closure, a flap procedure is indicated. The closure of an oroantral fistula can be performed by different techniques. Buccal flaps are often indicated in closure of small to moderate size defects. However, reduction of buccal vestibular height like the Rehrmann flap following this procedure makes it difficult to use prosthesis in future. Alternatively, the buccal advancement flap, and harvesting retromolar bone, prolamin gel, acrylic splint, guided tissue regeneration (GTR), and bone grafts can be successfully used for closures of OAF of less than 5 mm. However, over recent years grafts including free mucosal (FMG) or connective tissue grafts (CTG) are increasingly being used to close small to moderate size defects in the premolar area. The combination of the buccal flap and the buccal fat pad is appropriate for fistulae located in the second and third molar area. Closure of defects larger than 5 mm can be performed using one of the following procedures: combination of an endoscopic and per-oral BFP flap approach, BFP flap, pedicled buccal fat pad, modified submucosal connective tissue flap, distant flaps, autogenous bone grafts, allogenous, synthetic materials/metals, and other techniques. Ideally, the Bio-Gide®-Bio-Oss®⁻ Sandwich technique (Geistlich Biomaterials, Wolhusen, Switzerland) achieves both bony and soft tissue closure of OAF. In any case, it should be clear here that the technique for closure the OAF always depends on the indication and as well as the experience of the surgeon. It is often easier for a beginner to use a PTFE membrane or Rehrmann flap than to mobilize elaborate flap techniques and structures which are at risk, e.g., bone graft transplantation (BGT), injury of the arteria palatina and corpus adiposum buccae (buccal fat pad). Moreover, when searching deeply for the nervus faciali, injury of the nerve may occur. The dentist must be able to assess his abilities and, accordingly, choose the therapy to close the OAF.