A pedicled buccal fat pad flap graft was found to provide a high success rate of oroantral fistula closure in the present study, which concurs with the findings of several other studies [1, 5, 7,8,9,10]. The high success rates of BFP flaps are attributed to a rich blood supply [11, 12] from the maxillary artery (buccal and deep temporal branches), superficial temporal artery (transverse facial branch), and facial artery (small branches).
In a previous study, the main cause of OAF was tooth extraction [10], whereas in the present study, the main cause was cyst enucleation or benign tumor resection; we ascribe the difference to the fact that the present study was conducted at a university hospital. The second-most common cause was tooth extraction and the third-most was implant or bone graft failure. Interestingly, unlike previous reports, implantation and extraction contributed equally to OAF in our cohort. Implantation and bone grafting are now being widely applied, and thus, the number of patients with maxillary discomfort due to maxillary implant or bone graft failure [4, 13] and the number of oroantral fistula cases caused by implants and bone graft failures continue to increase.
Interestingly, two patients with bilateral OAF attributed to implants or bone graft failures were treated by BFP on right sides and a buccal advanced flap on left sides, because of smaller OAF sizes on left sides. Unfortunately, after a few weeks, both patients experienced left side OAF recurrence. Closure was achieved by BFP in both, and subsequently, OAF did not recur in either patient. In addition, three patients with OAF caused by implant failure experienced buccal advanced flap failure and were successfully treated by BFP. Based on these experiences, we are inclined to recommend BFP as the treatment of choice for OAF caused by implant failure, but further research is required.
The influences of the effects of age or sex on BFP volume have not been previously studied; accordingly, we advise that before a pedicled BFP flap is used for OAF closure, individual BFP volume be calculated from radiographic images (e.g., CT or MR) to assess whether coverage is possible. Also, additional studies are needed to determine the maximum volume that can be harvested based on considerations of gender, age, and individual variations.
The major limitation of the present study is that it was conducted using a retrospective design. Although all variables in medical records were carefully examined, the possibilities of inaccurate and misleading records cannot be ruled out. Furthermore, our results reveal associations and not causal relations between variables. Given that the numbers of implant and bone graft associated procedures are likely to increase further, we suggest an approach other than a buccal advanced flap and a palatal rotational flap be used to treat OAF. Despite the high success rate of BPF grafting, randomized controlled trials are needed on the topic as the amount of research performed to date is limited.