Canine Oronasal Fistula

Mona Lisa has a common problem. Dental calculus and resulting gingivitis have caused tooth loss, including her upper canine teeth.

Mona Lisa is an Italian Greyhound with a sweet personality.

Oronasal fistula occurs when an upper canine tooth is lost to disease or trauma, resulting in a passageway from the mouth to the nasal passages.

Some pets are more likely to have dental disease than others. Contributing factors include:

  • pH of the mouth/saliva
  • resident bacteria
  • eating soft food
  • inability to brush teeth frequently
  • poor nutrition

Mona Lisa is not cooperative for tooth brushing, plus she has inherent factors that predispose her to rapid tartar collection and resulting recession of the gums. Once a tooth loses gum support, and bone around the roots begins to deteriorate, a tooth will not be anchored in place much longer.

A dog’s upper canine teeth have extremely long roots, almost as long as the crown of the tooth. With that much support, they will remain in place despite substantial undermining by root disease. Often they are among the last teeth a dog loses.Here, the flap from the palate has closed the opening (fistula) and the buccal (cheek) flap is about to be closed.

Their extraction causes a problem because the tip of a healthy canine tooth root is separated from the nasal passages only by a thin layer of bone. Early in the process of root disease that bone is lost, and the tooth acting as a “plug” is the only barrier to food entering the nasal cavities during meals. The resulting passageway is called an oronasal fistula.

Potential sequelae  include impaction of the nasal passages with food, infection, sinusitis, even aspiration pneumonia if inhaled food enters the lower airway.

Most practitioners prefer to allow a time period between extraction and surgical repair of the fistula. Doing so allows the area to “quiet down,” become less inflamed, and even reduce the diameter of the opening.

The final product, repair completed. Healing will be complete in a few weeks and sutures are self-dissolving.

Surgical repair is sometimes referred to a veterinary dental expert and we chose to have Dr. Andy Duke of Mobile, AL, perform Mona Lisa’s procedure. I have done this repair before and many general practitioners do.  Dr. Duke is a Fellow in the Academy of Veterinary Dentistry.

The process begins with creating two flaps, one that comes from the hard palate, one from the adjacent cheek. The two flaps are “married” to join over the opening, thus ending communication between the oral and nasal spaces.

The accompanying photos show her left fistula prior to surgery, the first flap sutured closed and the final view with the surgery finished.

Most veterinary dentists administer broad-spectrum antibiotics and pain-relieving medications after surgery. Mona Lisa’s sutures are absorbable, negating the need for postoperative suture removal.

See you next week, Dr. Randolph.

Related posts:

  1. Dental Care Can Be Complicated
  2. Pet Dental Hygiene Important For Overall Health
  3. Canine Influenza

One Comment to “Canine Oronasal Fistula”

  1. Bo Reich, DVM 1 September 2011 at 1:17 pm #

    Those are great pictures, excellent article! Thanks!


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