French Bulldog Puppy Spontaneously Pushes His Jaw Back

A puppy’s jaw spontaneously grew back after Cornell veterinarians removed the majority of his lower left mandible due to cancer. Although this phenomenon has been documented in children, this is the first reported case of this type in dogs of any age and breed.

Tyson, a 3-month-old French bulldog, was originally scheduled to visit Cornell Dentistry and Oral Surgery for cleft palate surgery in spring 2023, when his primary veterinarian noted a cancerous tumor on his jaw.

“Tyson’s tumor was an oral papillary squamous cell carcinoma, which is a malignant cancer in dogs,” said dentistry and oral surgery resident Alexandra Wright, DVM ’18, who led Tyson’s care team. “Oral squamous cell carcinoma is the second most common malignant oral tumor in dogs, and this papillary subtype has previously been reported in young dogs.”

Wright published a report on this matter in Frontiers of Veterinary Sciencewith co-authors Dr. Nadine Fiani, associate clinical professor and section head, and Dr. Santiago Peralta, associate professor in the Department of Dentistry and Oral Surgery.

Wright explained to Tyson’s owners, Melissa Forsythe and Mike Lacagnina of Rochester, New York, that to remove the tumor, the majority of the puppy’s left lower mandible had to be removed, which meant life without a fully functioning lower jaw.

“We didn’t know if we wanted to put a puppy through all of this. The prognosis at the time was uncertain,” Forsythe said.

However, because Tyson’s CT scans were clear, meaning the cancer had not spread to other sites in the body, “we decided to give him a chance and go ahead with the operation. We didn’t know that his jaw would grow back.

Although there have been anecdotal cases of portions of mandibles regenerating in young dogs, this did not seem likely for Tyson due to the amount of bone removed.

The case report suggests that he managed to exceed all expectations thanks to a significant amount of periosteum, a thin membrane that covers bone surfaces, preserved during the surgical procedure. The periosteum contains blood vessels and nerves that support the bone and are essential for the growth of the original mandibles.

“It was probably imperative for the regeneration of the new bone,” Wright said. It also helped that the dog’s tumor was detected so early, although the precise reason for the jaw regrowth in Tyson’s case remains a historical mystery.

“More needs to be done to understand the likelihood of this happening in other dogs and whether a specific age range makes a difference,” Wright said, “but this case documents a very positive surgical outcome in a potentially life-threatening situation .”

Tyson’s new mandible is almost as functional as the original, although it is technically considered abnormal because it no longer possesses certain features. For example, there is no mandibular canal, where major blood vessels and nerves typically reside, and there are no teeth. However, it is the same length as the one on the right, which prevents any drift, and there is no trace of cancer in the regenerated bone.

After this operation, Tyson underwent another to treat his cleft palate.

“He spent most of his childhood wearing an e-collar, unable to play with toys or chew on anything,” said Forsythe, who would take him for walks around the house to keep him stimulated. “He was the best patient.”

She still doesn’t give him hard food or hard toys, but he enjoys her water-soaked kibble and lots of soft toys.

Forsythe keeps Wright updated on Tyson’s life after his time at Cornell. He recently completed his obedience diploma, passed his canine good citizen test and participated in a Christmas parade with his dog training friends. Wright describes this as the most rewarding part of the business.

Forsythe hopes Tyson’s result will benefit other dogs with this diagnosis. Wright agrees: “His case now demonstrates the possibility of complete bone regeneration when working with such a young patient. »