This patient presented to evaluate a hole in her left maxilla that appeared after dental work was performed several years prior. At that time both maxillary canine teeth were extracted. Since then she has sneezed intermittently and was otherwise in good health. Her owners became concerned recently when she started pawing at her muzzle. Below are photos of the right and left sides of her dental arcade.
Notice the arrow pointing out a hole in the right maxilla the owner did not know was present.
This patient had bilateral oronasal fistulas (ONF), which is an abnormal communication between the mouth and nasal cavity. After creating a large gingival flap with a wide base, all granulation tissue was debrided from the alveolar bone to expose only a boney rim. Despite a very small hole in the buccal mucosa grossly, the photo shows how extensive the ONF was on the right side.
Step 1: I typically use a thin, sharp periosteal elevator to debride ALL of the granulation tissue until the ONF looks this clean.
The ONF on the opposite (left) side after lifting a gingival flap and debridement of the granulation tissue surrounding the ONF appeared like this.
Step 2: After debridement I use a thin sheet made of natural demineralized cortical bone called Ossiflex (Veterinary Transplant Services). They provide a surface compatible with bony integration and epithelialization. You can see the material tacked into place over the ONF in the photo using monocryl suture.
Step 3: A big key to optimal healing is releasing the gingival flap using a blade to eliminate any tension. When placing the flap into place with your forceps it should stay there without having to tug in into position.
Step 4: Closure should be meticulous with simple interrupted sutures. One tip is to blow air along the suture line and if there is a “puff” of air that enters causing the gingiva to lift, I add another suture to close that area until there are no “puffs”.
Step 5 (Aftercare): If your practice has access to a therapeutic laser, post op daily laser treatments for chronic ONF healing can stimulate healing tremendously. The patient should keep an e-collar on until complete healing occurs and eat a softened food.
I saw the patient for rechecks in 1, 2 and 4 weeks at which point the area had completely healed. Once an ONF heals, there is no longer communication between the mouth and the nose.