Dental Tribune U.S. Edition

Why shouldn’t you ‘look a gift horse in the mouth’? An interview with veterinarian Richard B. Tanner at the Rood & Riddle Equine Hospital in Lexington, Ky. By Robin Goodman, Group Editor Have you ever wondered where the expression “don’t look a gift horse in the mouth” came from? Well, if you know a little about hors- es you probably know the answer. If you don’t: it’s because a horses’ teeth show the horse’s age. Thus, out of politeness, if you are going to look the horse in the mouth, you should wait until the one who gave you the horse is not around. During an October 2010 visit to the World Equestrian Games (WEG) in Lexington, Ky., to watch the jump- ing event, I realized that although I rode horses competitively in my childhood for eight years and am now back in the saddle fairly regu- larly riding a friend’s horse, I still know very little about the growth and care of equine teeth. As a result, I visited the Rood & Riddle Equine Hospital booth, a sponsor of the WEG, and asked if one of their veterinarians was avail- able for an interview. A few days later, I was treated to a tour of the hospital and was able to meet with Richard B. Tanner, DVM, to get the full strory on equine dentistry. Dr. Tanner, how long have you been a veterinarian? I graduated and began an internship with Rood and Riddle Equine Hospi- tal in 2005. I have remained with the hospital since graduating and have made equine dentistry a focus area of my practice. What are the basics in terms of horses’ teeth? Horses’ teeth are constantly erupt- ing, which of course is very different than you or I. By the time we’re 18 or 20 years of age, all of our teeth have erupted as far as they are going to, and vertical crowns are as exposed as they’re ever going to be. However, this is not the case with horses. Their teeth continue to erupt up until their 20s. As they get older, the teeth wear out, but they’re constantly erupting. If you took a radiograph of a young horse, you’d see that the tooth roots are extremely long. As they erupt, the teeth get longer and lon- ger, and the upper arcades grind against the lower arcades. The pre- molars and molars are the ones we watch very closely, and the reason for this concern is that in a horse’s head, the maxilla is quite a bit wider than the mandible. If you look at the skull we have here on the table, you’ll see very clearly that the maxillary teeth do not come into perfect contact with the mandibular teeth. A horse’s normal chewing motion is side to side and slightly forward. If you’ll note on this horse skull, you can see all the sharp points on the buccal sides of his teeth. These points are of course enamel, but it’s also cementum, a bonelike com- pound. If the horse doesn’t have a constant grind and good occlusal surface contact with the mandibu- lar arcade, the buccal side of the tooth continues to erupt. Indeed, the entire tooth is erupting, you just don’t see it because they wear part of it away with normal chewing. As a result, an adult horse needs an annual visit from the vet to grind that buccal surface down to get rid of the sharp points, which is called “floating teeth.” Younger horses will need two visits per year though. What will happen if you don’t do this are ulcerations along the Equine Dentistry DENTAL TRIBUNE | May 201110A AD Dr. Brad Tanner, a veterinarian at the Rood & Riddle Equine Hospital in Lexington, Ky., sits among some of the implements he uses in equine den- tistry. (Photos/Robin Goodman, Dental Tribune America)