Intra-sinus complex odontoma management simultaneously to oroantral communication closure: Why remove it?

The oroantral communication is considered one of the most frequent complications in oral surgery, especially in extractions of posterior teeth in the maxilla, treatment of cystic lesions, neoplasms, osteomyelitis and trauma in the region of the maxillary sinus, forming fistulas. However, ectopic third molar and lesions such as odontomas are rarely found simultaneously in the maxillary sinus. This report shows a successful treatment performed in a specific case of oroantral communication, associated to an underdiagnosed complex odontoma and an impacted ectopic third molar into the maxillary sinus and discuss the requirement of intervention. The treatment strategy involved clinical and surgical management through the oroantral communication, avoiding additional bone access to the maxillary sinus. This proposal presented a satisfactory result, and at six months after surgery, the patient has an excellent evolution, proving to be a successful strategy.


Introduction
Oroantral communication (OC) is a communication between the mouth and the maxillary sinus, which may or may not give rise to oroantral fistulas, which are permanently epithelized paths between these cavities (Daif, 2016). It is considered one of the most frequent complications in oral surgery, occurring especially in extractions of posterior upper teeth. With the communication, there is even the possibility of displacement of teeth and roots into this cavity (Hupp, 2019). The treatment of cystic lesions, neoplasms, osteomyelitis and trauma to the maxillary sinus region can also result in OC (Daif, 2016). Patients on drug therapy containing bisphosphonates or other drugs with anti-resorptive and anti-angiogenic properties, when submitted to extraction of posterior upper teeth, are at high risk for the development of OC if they develop osteonecrosis in the posterior maxilla induced by such drugs (Greenberg, 2004). In addition, the prevalence of OC has increased among patients undergoing sinus bone grafts and implant installation in this region (Park et al, 2019).
Surgical treatment of OC can be immediate, performed during the operation, preventing the installation of fistulas and, consequently sinusitis, or late, especially indicated when an oroantral fistula and sinusitis are already installed. Before any surgical treatment is instituted in these late cases, it is preferable to previously treat sinusitis through drug therapy and / or sinusectomy, aiming to adapt the environment and clear the affected maxillary sinus. OC whose bone defects do not exceed 3 mm, tend not to form oroantral fistulas and can close spontaneously in 1 to 2 weeks, with simple local wound care and patient guidance, but larger defects usually require some more refined reconstruction to prevent the installation of fistulas (Daif, 2016;Park et al, 2019).
Among the methods available for closing the OC, the pedicled buccal fat pad flap (PBFPF) is a simple and reliable flap for solving these communications. Egyedi was the first to describe in 1977 the use of PBFPF for the closure of OC and persistent oronasal communications in 4 patients after resection of tumors in the posterior maxilla (Toshihiro et al, 2013;Egyedi, 1977). Considering its rich blood supply, its easy accessibility and its proximity to defects of the posterior maxilla, it is especially indicated for defects larger than 5 mm, often associated with an initial inflammatory condition, frequently found in cases of pre-existing fistulas (Daif, 2016;Park et al, 2019;Yang, Jee & Ryu, 2018). In a case review using PBFPF, Singh, Prasad, Lalitha & Ranganath, (2010) revealed the closure of OC as the main indication of this flap.

Methodology
The interventional, descriptive and qualitative study was developed as a case report of the treatment and monitoring of a patient. The history of the disease and other information about the case were collected through the physical examination of the patient, after authorization and signature of a Informed Consent Form, as (Brown et al, 2016;Rodrigues et al, 2021;Mendes, Bonardi, Silva, Crivelini & Bassi, 2020). The case report is presented based on a simple literature review with the descriptors (Maxillary sinus; Odontoma; Oroantral fistula) in PubMed and Web of Science, and included references from 1977 to 2020. For the conduct of the case, registration and publication, approval by the Ethics Committee was not required, but Informed Consent was obtained and signed by the patient. Research, Society and Development, v. 10, n. 6, e57110615389, 2021 (CC BY 4.

Case Report
A 73-year-old male patient was referred for evaluation of OC, complaining of altered taste, fluid and food flowing out of the nasal cavity, bad breath, pain and recurrent nasal congestion after tooth extraction. At oroscopy, a 3 mm diameter oroantral fistula was observed in the region of tooth 27 (Figure 1).  The treatment of sinusitis was started with amoxicillin 500 mg + clavulanate 125mg three times a day for 7 days, irrigation with 0.9% saline solution, two applications of 20 ml, three times a day, and mometasone 50 mcg, two jets in the left nostril, twice a day.

Discussion
Odontomas in maxillary sinus can cause drainage obstruction (large ones) and even serious complications such as orbital infection, epidural and subdural empyema, meningitis, cerebritis, cavernous sinus thrombosis, brain abscess and death.
They may also exert significant influence in tooth displacement into the sinus, even towards the orbital floor (Grupta & Das, 2015;Singer et al, 2007).
About 12% of patients treated by pedicled buccal fat pad flap had a history of failure in previous vestibular flap closure. Stajcic (1992), described the success in closing 56 cases of communication using the buccal fat pad, considering it safe and efficient. Furthermore, it seems to be superior to the palatal flap, and the rare cases of failure usually involved smokers, and the fistulas occurring lately (el-Hakim & el-Fakharany 1999;Jain, Ramesh, Sankar, & Lokesh Babu, 2012;Nezafati, Vafaii, & Ghojazadeh, 2012). Although Caldwel Luc access is a traditional approach for the removal of teeth or foreign bodies in the maxillary sinus, in this case, the use of the present oroantral communication avoided additional ostectomy in an intact maxillary sinus wall, solving a surgical complication in just one surgical time (Ramanojam, Halli, Thakur et al., 2011;Hebbale & Bhardwaj, 2013;Courtot et al, 2021).
In addition, the double-layer technique (pedicled buccal fat pad flap with buccal mucoperiosteal flap overlapping it) avoids secondary epithelization, optimizing the OC closure, as used in this case (Jain et al, 2012).
Considering all clinical conditions ivolved, this surgical strategy solved simultaneously a rare sinusal complex odontoma, an ectopic impacted tooth and a chronic oroantral communication, easily and uneventfully, proving to be a valid alternative for treatment (Ramanojam et al, 2013;Grupta & Das, 2015;Kwon et al, 2020;Alonso-González et al, 2015).

Conclusion
As evidenced in the literature, it is concluded that the use of PBFPF to treat oroantral communications, among other applications, presents itself as a safe alternative and with an excellent prognosis, thus allowing a successful strategy for the treatment of the case presented.
Finally, studies with a greater number of similar cases, comparing the approaches and the results obtained would contribute to define a treatment choice algorithm in those cases.