Oroantral (Oromaxillary) Fistula Patient Information

Anh Q. Truong, MD

Bellevue ENT

1231 116th Avenue NE, Suite 915

Bellevue, WA 98004

Phone: (425) 454 - 3938

What are the maxillary sinus and alveolar ridge?

The paranasal sinuses are mucosal lined and air-filled spaces in the bones around your nose. There are typically four pairs of sinuses. The maxillary sinuses are located the cheek region of the face, immediately above the upper teeth. Below the air-filled maxillary sinuses are the alveolar processes, which is bone under the gingiva (gum line) that contains the teeth and the tooth sockets.

Usually, the tooth sockets are separated from the maxillary sinus by the thickness of the alveolar ridge. However, some teeth can project into the maxillary sinus with a very thin layer of bone between them. It is not unusual for patients to experience dental sensitivity during a sinus infection.

What is an oroantral fistula (oromaxillary fistula)?

An oroantral fistula is an abnormal communication between the mouth and the maxillary sinus that can occur due to a defect in the alveolar process and the gingiva (dental gum). This can occur after a tooth is extracted and an opening is created into the maxillary sinus due to a very thin alveolar process or due to the presence of a dental cyst.

How does an oroantral fistula typically present?

Most patients with an oroantral fistula are completely asymptomatic once the fistula closes up spontaneously. However, some patients may develop a persistent opening with chronic mucous drainage from the maxillary sinus directly into the mouth. In addition, these patients are prone to developing a sinus infection.

Symptoms of an oroantral (oromaxillary) fistula typically include chronic drainage into the mouth, reflux of food into the sinus, escape of air into the mouth with nose-blowing, foul-smelling discharge into the mouth, and symptoms of a sinus infection. The symptoms may fluctuate in severity and can improve with antibiotics.

Figure 3. An oroantral fistula (left) and an active sinus infection with purulent discharge (right).

What should you expect during your visit with your ENT doctor for an oroantral fistula?

During your visit, your ENT doctor will perform a complete history and physical exam. A procedure called a nasal endoscopy with a fiberoptic endoscope may be performed to further evaluate the nasal anatomy and sinus pathology deep inside your nose. The gingiva (gum) may be probed with a Q-tip or a lacrimal probe to identify the site of the fistula. Depending on your history and examination, your physician may refer you to obtain additional studies including a CT scan and blood tests.

How is an oroantral fistula treated?

The treatment for an oroantral fistula depends on the patient’s presentation. In general, most patients will have spontaneous closure of a small oroantral fistula (< 2 mm) with conservative treatment. This includes maintaining good oral hygiene, avoiding nose blowing, sneezing with the mouth open, and treating the sinus infection with antibiotics as needed. Large oroantral fistulas with recurrent sinus infections may require surgical treatment.

When is repair of the oroantral fistula and sinus surgery indicated?

Patients with an oroantral fistula that are symptomatically bothersome, and do not close up with conservative treatment for 1-2 months, will need surgical repair. This may include debridement and direct closure or closure with a local advancement flap (borrowed tissue from the cheek or palate). In patients with a concurrent sinus infection, sinus surgery is often necessary to evacuate the infection and to provide an alternative route for the sinus to drain while the fistula is healing. Click here to learn more about closure of an oroantral fistula, sinus surgery, and post-operative instructions for an oroantral fistula.

Learn more about surgery for an oroantral fistula, postoperative instructions after an oroantral fistula closure, sinus surgery, and postoperative instructions after sinus surgery.