Getting Closure by Dr. Andonis Terezides

Performing a double-layered closure of a large chronic oral/antral fistula using buccal and mucosal advancement flaps.

Tooth extraction involves general risks such as pain, swelling, bleeding, infection, incomplete removal, dislodgement/displacement of tooth fragments, or damage to adjacent teeth, restorations or other anatomic structures. In the maxilla, one risk is a sinus perforation resulting in an oral/antral communication, whereby a communication develops between an extraction site and the maxillary sinus. Failure for the communication to seal and mucosalize may result in a chronic oral/antral fistula.

Preoperative radiographs should be critically evaluated to assess the risk factors for oral/antral communication, which include:

• Pneumatized maxillary sinus.
• Little or no bone between the root and the maxillary sinus.
• Widely divergent or dilacerated roots.
• Periapical pathology or abscess.

Preventing most sinus perforations in difficult maxillary extractions is possible by ensuring good visualization and lighting, and opting for surgical extraction to trough or section the roots for individual removal. When elevating the tooth and roots, proper surgical technique to avoid excessive apical pressure is necessary. Referral to an oral and maxillofacial surgeon is advised for these complex, higher-risk extraction procedures.

If a sinus perforation does occur, management is based on the size of the communication. Sinus perforations 2 millimeters or smaller generally do not require treatment. Perforations 2–6mm are initially managed with attempts to promote formation and maintenance of a blood clot within the socket. Many surgeons prefer to use an absorbable gelatin substance such as gelfoam or a collagen plug secured with a figure-of-eight suture. The patient is then placed on sinus precautions: no sneezing through nose; no nose-blowing; and avoid straws, smoking and habits that would cause differing pressures between the oral cavity and paranasal sinus system, which could potentially displace or dislodge a blood clot. The patients are also placed on antibiotics such as amoxicillin, cephalexin or clindamycin, and a decongestant such as pseudoephedrine, to decrease the potential for developing a maxillary sinusitis.

Perforations 7mm or greater will usually require surgical intervention for wound closure in the form of a flap or combination of multiple flaps (for example, palatal rotational flap, buccal mucosal advancement flap, buccal fat-pad advancement).

Timely referral to an oral and maxillofacial surgeon for management of this complication is important, especially to minimize the development of sequelae such as sinusitis or chronic oral/antral fistula formation.

Case study
A 63-year-old patient was referred to the oral and maxillofacial surgery clinic by his new general dentist (Fig. 1, p. 64). The patient had undergone full-mouth extractions at a facility in another state approximately two years previously. His treatment had been complicated by the development of an oral/antral communication at the time #14 was extracted. He was placed on antibiotics and given the sinus precaution instructions mentioned above, but no initial attempts at surgical repair were made at his original facility. Soon afterward, he moved away and was lost to follow-up.

Because the size of the communication was so large, it failed to heal and close primarily, ultimately resulting in a long-standing chronic oral/antral fistula. The patient complained of constant food and liquid trapping. He complained that no dentist was willing to fabricate a denture for him without first having this defect repaired.

Clinical examination revealed an edentulous maxilla and mandible with a large defect in the left posterior region approximating the second molar region. This defect measured 11mm by 13mm in its greatest dimension (Figs. 2 and 3, p. 64).

The panoramic radiograph demonstrated evidence of alveolar bone atrophy and resorption, along with a visible defect in the residual dental alveolus (Fig. 4, p. 64). Further radiographic investigation with a CBCT scan (Figs. 5 and 6, p. 64) demonstrated a far greater defect beneath the mucosa, measuring 15mm across (buccal/palatal) by 16mm (anterior/posterior), and 20mm from alveolar crest superiorly along the lateral maxillary wall/zygomatic buttress. The CBCT scan also demonstrated a thickened and reactive maxillary sinus mucosa with several polyps. The maxillary sinus osteum, which drains to the inferior nasal meatus, was noted to be patent.

Buccal up: The treatment plan
During the preoperative consultation, the patient was given a detailed informed consent discussion and offered treatment that included a sinusotomy/antrectomy with debridement of the inflamed, infected sinus mucosa and polyps, and a two-layered closure using a buccal fat-pad advancement flap and a mucosal advancement flap. The patient elected to undergo the procedure awake under local anesthesia, declining treatment under IV sedation or intubated general anesthesia.

I prefer using the buccal fat pad because it has a robust blood supply. It is essentially an axial pattern flap supplied by the maxillary artery (buccal and deep temporal branches), superficial temporal artery (transverse facial branches) and facial artery (small branches from the buccinator artery). The buccal fat pad can easily cover defects of this size and provides for a living tissue foundation to overlay with a second layer of tissue via the mucosal advancement flap.

Classic anatomic descriptions describe the buccal fat pad as having a central body with four processes: buccal, pterygoid, pterygopalatine and temporal (superficial and temporal). More recent descriptions describe the buccal fat pad having three lobes—anterior, intermediate and posterior—that are encapsulated and have supporting ligaments along with their arterial supply. The buccal and zygomatic branches of the facial nerve as well as the parotid duct are lateral to the buccal fat pad. Care must be taken during surgery to avoid injuring these structures during surgical dissection.

The procedure
On the day of surgery, the treatment plan was reviewed in detail again with the patient, including the risks, benefits, indications and alternative treatments. Informed consent was witnessed and signed. He was given a preoperative rinse of 0.12 percent chlorhexidine oral rinse and directed to swish for 1 minute, then spit.

Local anesthesia was provided using four carpules of 4 percent septocaine with 1:100,000 epinephrine (6.8ml, 272mg septocaine, 0.068mg epinephrine) to provide left posterior superior alveolar, middle superior alveolar, greater palatine and V2-division blocks along with supplemental local infiltration.

An incision was performed along the alveolar crest with caution to approach the fistula site, anticipating a much larger defect extending from the visible fistula. A distal/buccal releasing incision over the tuberosity and an anterior releasing incision were performed. Subperiosteal dissection was performed at both ends of the latter, with the goal of carefully approaching and identifying the full extent of the defect. A small palatal flap was also raised along the alveolar crest (Figs. 7a and 7b).

Once the defect was identified, a series of curettes was used to debride the maxillary sinus of any infected, diseased sinus mucosa and any visible polyps (Fig. 8). The specimens obtained during the sinus debridement were submitted in formalin to the pathologist for histopathologic evaluation. The sinus was then irrigated with sterile saline and 0.12 percent chlorhexidine rinse.

The buccal flap was retracted, and the position of the parotid duct was visualized and noted. A 2-centimeter back-cut through the periosteum was performed (Fig. 9) and hemostats were used to perform blunt dissection identifying the buccal fat pad. As the tissues were spread, the buccal fat pad flowed downward. Careful blunt dissection continued to further mobilize the buccal fat pad to extend down over the defect (Fig. 10).

A second layer of closure
Next, additional submucosal dissection was performed with tissue-dissecting scissors to mobilize the overlying buccal mucosal tissue as a mucosal advancement flap to provide for a second layer of closure in a tension-free manner (Fig. 11).

Using a 702 bur on a surgical handpiece, several small holes along the anterior buccal aspect of the defect, approximately 2–3mm away from the bony margin, were placed to be used as anchorage points. The buccal fat pad was draped over the defect and secured to the bur holes using 4-0 PGA sutures in a simple, interrupted manner. The buccal fat pad was then tucked under the palatal flap edge and further sutured to the palatal flap margin. This effectively covered and obliterated the defect (Fig. 12).

For smaller defects, some surgeons prefer to stop at this point, leaving the buccal fat pad exposed to mucosalize on its own in three to six weeks. However, with a defect this large and the patient being a noncompliant heavy smoker, I believed the best chance at a successful resolution would require a second layer of closure using a buccal mucosal advancement flap. The flap was mobilized over the site using hemostats and tissue scissors to carefully release it, and 4-0 PGA sutures in a horizontal mattress fashion were used to reapproximate the tissue margins in a tension-free manner. Additional mucosal closure was achieved using 3-0 chromic-gut suture using a running technique (Figs. 13 and 14). The patient was placed on a postoperative regimen of:

• Amoxicillin: 500mg po TID x 10 days.
• Sudafed: 60mg po BID x 5 days.
• Afrin nasal spray: Two puffs each nare BID x 5 days.
• Hydrocodone/APAP 5/325mg:
  One tablet po q6h prn pain.

He was given sinus precaution instructions and emphatically instructed to refrain from smoking.

Follow-up progress
At the two-week follow-up appointment, the patient reported an uneventful postoperative course with little pain or discomfort. His clinical exam revealed good wound healing with apparent achievement of closure/repair of the large chronic oral/antral fistula (Figs. 15 and 16), despite his continued heavy smoking.

At six weeks postoperatively, the patient was seen again for follow-up. The incision site was noted to be closed and mucosalized, without any evidence of the fistula. Again, he was symptom- free, and no longer experiencing fluid leakage (Figs. 17 and 18).

The patient will return to undergo pre-prosthetic surgery in the form of mandibular alveoloplasty, lingual tori removal and a maxillary vestibuloplasty procedure. Eight to 12 weeks later, a prosthodontist colleague will take impressions to begin fabrication of his definitive removable complete dental prosthesis.

Conclusion
Buccal fat-pad reconstruction techniques have been successfully used in defects extending up to nearly 4cm in size. Larger defects, however, are prone to dehiscence and may require additional flaps. The greatest disadvantage of the buccal fat-pad flap is that it may create a lack in vestibular depth, which may complicate the fabrication and limit the mucosal retention of a removable complete dental prosthesis.

The buccal fat pad is an extremely versatile anatomic structure for oral and maxillofacial reconstruction because of its relative ease to access and dissect, its robust blood supply, its quick mucosalization potential, and its ability to reach to distant defects in the maxilla. Many surgeons prefer this technique over rotational palatal flap techniques because the procedure is quick, consistently reliable, cost-effective and well-accepted from a patient comfort and recovery standpoint.