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Not Your Average Root Canal

Endodontists go through years of training to become specialists in saving teeth. They acquire specific skills and knowledge to manage a variety of complex situations that may arise while diagnosing and treating their patients’ tooth pain. That holds true whether the patient is a human being – or a 400-pound bear. When zoo animals need root canal treatment, veterinarians and zookeepers turn to AAE-member endodontists for their expertise in saving teeth and relieving pain.

Bruce W. Overton, D.D.S.

You know the line from “The Wizard of Oz” about lions and tigers and bears? Well, AAE member Dr. Bruce W. Overton has performed root canal treatment on all three. Oh my!

Dr. Overton, a Diplomate of the American Board of Endodontics, is on retainer at the Metro Richmond Zoo, located just 20 minutes from his private practice in Midlothian, Virginia. And while some things about the work are very familiar – he orders his instruments for animals from the same company he uses for his human patients – other things are obviously very different.

Like the time he performed a root canal treatment on an Asiatic black bear – and had to first help seven other men lift a tarp cradling the 400-pound animal onto the surgical table.

“You see these animals on TV or in a magazine and they might not look that big, but when you get up next to them, one of their front paws is the size of a baseball mitt!” he said. “Mother Nature is incredible.”

Dr. Overton first began a relationship with the zoo about eight years ago when they approached him for help with a root canal procedure on a female lion named Nehru. By that time, Dr. Overton had more than a decade of experience working on dogs that were used in law enforcement and military work.

Saving animals’ teeth is essential for eating and self-defense, and root canal treatments can prevent potentially life-threatening infections. Still, Dr. Overton is modest about the work he does.

“The hard job belongs to the veterinarian who has to put the animals under general anesthesia and intubate them,” he said. “I will say, though, that when I’m in the mouth, I’m working fast. I know the veterinarian has a time constraint with the animal being under general anesthesia. Without cutting corners, I’m not wasting any time.”

And as much as he enjoys being in private practice, Dr. Overton said he finds the work on animals fascinating. “I don’t think there is any movie or picture that ever does justice to the beauty and majesty of these animals until you get right up close to them,” he said.

BearRootCanal MonkeyRootCanal
Dr. Bruce W. Overton (in blue surgical mask) treats an Asiatic black bear, with assistance from Metro Richmond Zoo owner and zookeeper Jim Andelin. Photo courtesy of Susan Overton. Dr. Kimberly A.D. Lindquist (in white lab coat) performs root canal treatment on an Allen’s swamp monkey that had broken off one of its upper canine teeth. Photo courtesy of John Lindquist.

Kimberly A.D. Lindquist, D.D.S., M.S.D.

It was a weeping sore under Noqui’s eye that alerted a zookeeper at Lake Superior Zoo in Duluth, Minnesota, that something was wrong with the animal, an Allen’s swamp monkey.

The zoo’s veterinarian correctly diagnosed an abscessed tooth, but she didn’t have the necessary equipment to perform a dental X-ray or repair the tooth. As luck would have it, that same veterinarian ended up treating the dog of a dental assistant who worked in the office of AAE member and District VI Director Dr. Kimberly A.D. Lindquist.

One thing led to another, and Dr. Lindquist found herself moving her microscope and “all the equipment I could think of” into the zoo’s medical facilities in January 2014 to perform her first animal procedure on a small, powerfully built monkey with greenish-gray fur.

Noqui was rescued by the zoo after being confined in a cage and had broken off one of his upper canines, likely on the cage’s metal bars. By the time Dr. Lindquist examined him, the pulp tissue had deteriorated and bacteria had lodged into the fractured tooth, creating a chronic abscess that presented as an extraoral draining sinus tract. The zoo wanted to save the monkey’s tooth to preserve his status with other monkeys.

Giving the monkey a sedative, intubating him and putting him under general anesthesia didn’t seem so different to Dr. Lindquist from what you’d experience in an operating room for humans. But that’s where the similarities ended.

As Dr. Lindquist recalled, “First of all, my frame of reference was different. The monkey was on a bed; I work with my patients in a somewhat reclined position, but not on a bed. His teeth are really long – 40-plus millimeters – and my instruments only went to 40. I had to modify or measure so my instruments could go where they needed to go. And getting a radiograph was next to impossible; he doesn’t have a very big mouth, his teeth are extremely long and they curve, and he has a pretty shallow palate.”

All of those factors, along with working around the intubation tube, made it a more difficult and longer procedure than Dr. Lindquist expected. She relied on her tools and “feel” to clean and obturate the monkey’s tooth. As a result, Noqui still has his tooth and his sinus tract has healed.

“I’m just happy he’s happy and healthy,” said Dr. Lindquist, a Diplomate of the American Board of Endodontics. She called Noqui a “beautiful animal” and said the work gave her a new appreciation for what goes on behind the scenes at a zoo.

“It was a great, interesting, wonderful learning experience,” Dr. Lindquist said.

Thomas J. Beeson, D.D.S.

Most people leave class reunions with warm memories and funny stories. AAE member Dr. Thomas J. Beeson left his with a connection that led to performing dental procedures on monkeys, tigers, lions, bears, apes, leopards and more.

Dr. Beeson, a Diplomate of the American Board of Endodontics and associate professor and chairman of the Endodontics Department at Creighton University School of Dentistry, was at a high school reunion in 2006 when he ran into Dr. Julie Napier, a former classmate who had just been hired as the senior veterinarian of the Henry Doorly Zoo in Omaha, Nebraska. Half joking, he told her to call him if the zoo ever had trouble with the teeth of its tigers, since he had experience working on service dogs during his 22-year career in the U.S. Air Force.

About 18 months later, Dr. Beeson was contacted about Sanjay, one of the zoo’s white tigers. During a regular medical exam on the anesthetized white tiger, a zoo team discovered a canine tooth that was problematic and larger than normal. The animal was young, and had much more pulp space than expected because the huge canine tooth was still forming. After what they thought would be a routine root canal, the team had difficulty controlling the bleeding and reached out to Dr. Beeson for help. About a week later, Sanjay was anesthetized again and Dr. Beeson found himself staring into the massive jaws of a 450-pound white tiger. While most human teeth are less than an inch long, some of the tiger’s teeth were six or seven inches. Although Dr. Beeson was “very cautious” with the procedure, he was able to save the tiger’s tooth.

Since that 2007 visit, Dr. Beeson and the zoo have developed a close relationship. He teaches a course at Creighton that involves quarterly zoo visits to conduct X-rays, extract teeth or perform root canal treatment. All dental work is conducted under the supervision and with the approval of the zoo’s veterinarians, who Dr. Beeson praises for their scope of knowledge and dedication to the animals.

Of the animals he’s treated, Dr. Beeson was most in awe of the great ape. “The gorilla is just one big, solid muscle, and you know they could totally destroy you in seconds if they were awake,” he said.

To make sure that doesn’t happen, one zoo staff member is stationed at the animal’s head – his or her only job is to monitor the animal for any unexpected movement. There have been times when Dr. Beeson and his students have been told to stop what they’re doing immediately and to leave the room.

“We’ve never felt really threatened, but your heart does start beating a little bit quicker!” he said. “The comfort and safely of the animal is a priority for us and the zoo staff as well. Short, concise procedures on well-sedated and anesthetized animals are the norm.”

Dr. Beeson acknowledges that his team and students can’t help but be astonished at the animals they are helping. But they know they have a job to do.

“You’re in awe that you’re allowed to actually do this,” Dr. Beeson said. “But you’re trained to do something and your training has nothing to do with emotion. It has everything to do with technical ability. At some point, you have to get past it and do what you know how to do. It’s just on a different scale.”