An oroantral fistula (OAF) may develop as a complication of dental extractions, as a result of infection, or as sequelae of radiation therapy, trauma, and removal of maxillary cysts or tumours. The commonest aetiology of OAF is as a complication following extraction of maxillary posterior teeth.

Treatment modalities to repair OAFs following any cause include local and distant soft tissue flaps, autogenous bone grafts, allogenous materials, xenografts, synthetic metals and other techniques. Regardless of the technique, two principles must be observed. First, the sinus must be rendered free of infection with adequate drainage and the use of appropriate sinus antibiotics in addition to topical or systemic decongestants. Second, tension free closure of a broad base, well vascularized soft tissue flap.

Some traditional methods used in the repair of OAF include buccal advancement flaps, palatal rotation and palatal transposition flaps, tongue flaps, and nasolabial flaps. Recently, because of various advantages, buccal fat pad (BFP) is increasingly being employed in the repair of OAF and other oral defects worldwide.

BFP was first described by Heister (1732), who thought the structure was glandular and termed it the ‘glandula molaris’. Bichat is credited with recognizing the true nature of the BFP. Therefore, it is commonly referred to as the boule de Bichat or bolle graisseusse in French; it is called wangenfettpfropf or Wangenfettpolster (Wangen = Cheek + fett = fat, polster = pad-cheek, fat, pad) in German, and the sucking pad, sucking cushion, masticatory fat pad, or buccal pad of fat in English.

The BFP is a simple lobulated mass consisting of a central body and four extensions: buccal, pterygoid, pterygopalatine, and temporal ( Fig. 1 ). The main body is situated deeply along the posterior maxilla and upper fibres of the buccinator, covered with a thin capsule. The buccal extension lies superficially within the cheek and is partially responsible for cheek contour.

The main body of the buccal fat pad and its extensions and relations with important adjacent structures.

The buccal extension and main body together constitute 55–70% of total weight. The pterygopalatine extension of fat tissue extends to the pterygopalatine fossa and inferior orbital fissure. The pterygoid extension is a posterior extension that generally stays in the pterygomandibular space and packs the mandibular neurovascular bundle and lingual nerve. The temporal extension can be divided further into superficial and deep. The superficial part of the temporal process of the BFP stays between the deep temporal fascia, temporalis muscle, and tendon. The anterior end of it turns around the anterior rim of the temporalis muscle, and continues with the deep part. The deep part of the temporal process lies behind the lateral orbital wall and frontal process of the zygoma and turns backward into the infratemporal space. Each process has its own capsule and is anchored to the surrounding structures by ligaments. The size of the pterygoid and temporal extension is inconsistent, but is usually smaller than either body or buccal extension.

The superficial temporal fat situated between two layers of deep temporal fascia is a separate fat pad and differs in appearance, has a separate vascular supply, and is anatomically distinct from the BFP.

The parotid duct courses with the buccal branches of the facial nerve anteriorly (superficial), and on the lateral surface of the BFP, it penetrates the buccinator muscles, entering the oral cavity opposite the second molar. The facial vessels are in the same plane and mark the anterior extent of the BFP.

The BFP derives its blood supply from the buccal and deep temporal branches of the maxillary artery, transverses facial branches of the superficial temporal artery, and branches of the facial artery. The branches from different sources form the lobar subcapsular plexus by freely anastomosing with each other. Owing to its rich blood supply, it can be considered as a pedicled graft with an axial pattern. The rich blood supply may explain the high success rate with this flap. It may also be one reason for the quick epithelialisation of the fat.

The average volume of fat is 9.6 ml (range 8.33–11.9 ml). The size of the BFP is fairly constant regardless of overall body weight and fat distribution; even cachectic patients have BFPs of normal weight and volume.

The quick epithelialisation of the uncovered fat is a characteristic feature of the pedicled BFP flap and is histologically proven. The layer above the originally uncovered BFP consists of stratified squamous epithelium migrating from the adjacent mucosal regions.

The aim of this paper is to evaluate the long term effectiveness of pedicled BFP with or without buccal advancement flap in the closure of OAF.

Materials and methods

After obtaining ethics and research committee approval, a prospective observational clinical study involving patients requiring closure of oroantral communication (OAC)/chronic OAF was done in the Departments of Oral Surgery at Puducherry and Hassan. The study was carried out for 2 years from May 2008 to April 2010. The patients were all told about the procedure of using pedicled BFP for closure, its complications and the other options available for management including their advantages and disadvantages. Patients opting for BFP and willing to be followed up were included. Patients were excluded if they were above ASA 2, required radiation therapy following surgery or were immunocompromised. Fifteen cases were included and managed using pedicled BFP as the primary or secondary procedure (previous surgery had already been carried out unsuccessfully using another method to close the fistula) under local anaesthesia using lignocaine 2% with 1:80,000 adrenaline (except for one case that was carried out under general anaesthesia). Seven of the patients with chronic sinusitis and infection were treated using the Caldwell-Luc operation with OAF closure being performed at the same time. Cases with doubtful outcome were closed in two layers using BFP and buccal advancement flap.

The patients gave informed consent and were given amoxicillin 500 mg with clavulanic acid 125 mg three times daily (augmentin 625 mg) 2 days before the surgery. After obtaining adequate anaesthesia, excision of the fistulous tract and freshening of the wound edges was carried out. The upper vestibular horizontal incision, depending on the side involved, was made posterior to the second premolar and extended to the posterior margin of the fistula to expose the BFP. Careful manipulation and blunt dissection was carried out to mobilize and advance the flap to the recipient site ( Fig. 2 ). The flap was sutured in place with simple interrupted 3/0 polygalactin 910 sutures. The incision was closed over the bridge segment of the flap with sutures. Patients were warned against blowing their noses for 2 weeks. The preoperative antibiotic regimen was continued for the next 5 days. The antral triad of decongestant, antihistamine and analgesic was prescribed for 5 days.

Harvesting BFP using vestibular approach.

Cases with larger oral defects, those with an already raised trapezoidal flap, and patients with doubtful outcome were closed in two layers using BFP along with buccal advancement flap. After raising the trapezoidal buccal mucoperiosteal flap, a 1 cm vertical incision was made in the reflected periosteum posterior to the zygomatic buttress to allow exposure and advancement of the BFP over the bony defect where it was sutured to the palatal mucosa ( Fig. 3 ) followed by second layer closure with buccal advancement flap.

Two layered closure of OAF using buccal advancement flap and pedicled BFP.

Follow up lasted for 3 months, at intervals of 1, 4, 8 and 12 weeks to evaluate any postoperative complications such as wound dehiscence, necrosis or infection.