Diastema Widening: What You Need to Know About This Common Procedure

What is a diastema?

A diastema is a space between two teeth. Normal equine cheek teeth are in tight contact with each other. When two teeth drift apart slightly, feed can become trapped between them. This feed, in a dark, wet environment, allows bacteria to grow. The bacteria then eats away the gum tissue, creating pockets in the gum tissue called periodontal pockets. The condition is painful, and pockets can “tunnel” into sinuses, into nasal passages, or outside the horse’s face.

What do we do about it?

In an ideal world, we would be able to clean out the space and close it. However, this has proven almost impossible. The current treatment is called “diastema widening.” We use three progressively larger burrs (like drill bits) to remove tiny bits of each tooth, creating a channel. This channel is wide enough to prevent food from becoming trapped. The gum tissue will then heal and bacteria will die.

Before (left) and after (right) a diastema widening procedure. The image on the left shows a diastema with a periodontal pocket, which has already been cleaned of accumulated feed material.

What are the benefits?

Studies have shown that horses who quid (drop feed), lose weight, have bad breath and/or have bitting problems improved significantly after diastema widening. The accumulation of feed between teeth, and the associated gum disease, are painful to the horse. Treatment that resolves the condition will alleviate this pain. Though periodontal pockets may not resolve completely after treatment, the tissue will usually heal and the pocket will stop progressing. This eliminates the chance for formation of fistula (an open tunnel), which can create a sinus infection that is almost impossible to resolve.

Deep periodontal pocket between upper cheek teeth. The left image shows a deep, inflamed (dark red, bleeding) pocket, The image on the right shows a healed pocket (light pink, no bleeding) after diastema widening one year prior.

What are the risks?

 Diastema widening is a very low-risk procedure. The biggest risk is the risk of heat damage or accidental opening of the pulp cavity of the tooth. To avoid these complications, we only spend a few seconds at a time working on a space, and cool the tooth with water in between work sessions. The incidence of complications is about 1 in 200-300. Complications involve loss of the tooth, which may also occur if the diastema is not widened, due to spread of infection.

Diastema before (left) and after (right) the widening procedure