Oral Surgery

Oronasal Fistulas

This is a term used to describe a hole or communication between the oral cavity (mouth) and the sinuses. When you have such a fistula or hole it allows mucus from the sinus to drain into the mouth. It also allows liquids (saliva, water, etc.) from the mouth to go up into the sinuses (often seen as dripping or drainage from the dog’s nose).

Clinical Symptoms

Patients with oronasal fistulas may present with a variety of symptoms. The owner may notice sporadic or chronic sneezing. There may be a nasal discharge from one or both nostrils. Sometimes patients will present with no clinical signs indicating the importance of thorough examinations and periodic teeth cleanings.

Causes of Oronasal Fistulas

The most common cause of oronasal fistulas is from periodontal disease that has led to bone loss around the tooth resulting in fistula development. Other causes of oronasal fistulas include complications from past extractions, foreign-body penetration, bite wounds, neoplasia as well as Inherited or developmental clefts of the lip or palate.

Because periodontal disease is the most common cause for oronasal fistulas regular exams and teeth cleanings can’t be emphasized enough. Dachshunds are frequently affected. In these cases, bone loss is often present adjacent to the upper canine teeth.


Treatment requires the extraction of the tooth where the fistula is located. Merely extracting the tooth will not lead to closure and healing, instead a hole will remain between the mouth and the sinuses if additional surgery is not performed to close the fistula. Again, to avoid the development of these lesions, early recognition and appropriate therapy is required.

After the tooth is extracted, a mucogingival (tissue) flap is created so that the defect can be covered so that the fistula will heal. The flap must be designed to allow maximal blood supply (tissue perfusion) to the defect that it is being created for, and must be sized so that the flap is tension-free- otherwise the flap will not heal. A skilled surgeon is required to ensure that the flap will heal.


There are many different causes of oronasal fistulas. The fistulas can occur in both dogs and cats. Symptoms of fistulas vary but most commonly include nasal drainage and or sneezing. Proper diagnosis and treatment if important. Oronasal fistulas should be treated because appropriate treatment can dramatically improve the quality of the patient’s life.