Even though it would take six to nine months for all of Sugar Shack's baby teeth to come in, we could tell from our first examination, done on the day he was born, that the long-legged bay colt had a slight parrot mouth--his upper jaw was longer than his lower one.
We explained to his owner how the misalignment would affect his teeth as they emerged: His overlapping upper incisors would trap the lower ones, displacing them even farther backward, and it was possible that they could keep the lower jaw from growing forward. Over time, his first upper cheek tooth on each side would almost certainly develop a hook in front, where it overlapped a bottom premolar. These sharp hooks would be painful and would prevent the cheek teeth from meeting evenly. If we didn't intervene, it would be difficult for Shack to eat properly or carry a bit.
We laid out a plan: Filing the hooks during dental visits scheduled every six months once his teeth emerged would eliminate their sharp points and allow the colt's lower jaw to slide forward. We'd also address any problems caused by the abnormal growth pattern of his incisors so the lower incisors wouldn't grow up into the roof of his mouth.
As serious as that sounded, we assured his owner that Shack's parrot mouth was comparatively mild, so he would not need the orthodontic devices--wires or an acrylic mouthpiece--that are sometimes used to correct more severe problems. Regular care would keep his mouth in shape now and when his permanent teeth finally came in.
Despite our urgings, two years passed before we saw Sugar Shack after our initial visit. He had just begun groundwork and his owner was worried that the condition of his mouth might be contributing to some resistance she was encountering with him.
Although he looked shiny and fit, Shack's parrot mouth was evident. Jim sedated him and then set the mouth plates of the speculum on his incisors and gradually opened the ratchet to expose all the teeth. As we had predicted, hooks protruded downward from Shack's upper first cheek teeth. Behind the hooks, the premolars were slightly cupped out. His abnormal bite had caused them to wear that way.
Jim used carbide hand floats to reduce the hooks. After that single visit, the young horse was more comfortable and his owner saw a marked improvement in his training. We reminded her of the need for regular dental visits to keep Shack's bite as good as it could be, especially as his first permanent premolars came into wear.
This case report was excerpted from the article, "Age Related Tooth Troubles" which appeared in the November 2006 issue of EQUUS magazine.