by Spencer LaFlure, EqD

As wild horses roamed their domain, the excess growth on their hooves wore away naturally, leading to a balanced foot. This natural wear through lifestyle and environment is also true of the equine mouth, where balance is just as important to overall health.

Start up front

In its natural state, a horse would graze 14 to 18 hours a day on grasses containing silicas that wore or abraded the teeth in such a manner that the front teeth wore as they erupted. These front teeth, or incisors, are the keys to balance in the mouth. Their length and angle in a wild horse are similar to those in a domestic horse at around age fi ve, and should remain that way through the life of the horse. Beyond the age of fi ve, however, the front teeth of domestic horses begin to exceed the appropriate length and angle. This is when you start getting abnormal rotation of the TMJ (temporal mandibular joint), where the jaw hinges to the skull. The rotation of this joint dictates the wear pattern of the molars. The point of natural equine dentistry is to treat the cause of this problem, not the symptoms, by first maintaining the natural length and angle of the incisors. Further balancing of the molars cannot be accomplished without proper balance in the front of the mouth.

Equine dentists use an instrument called a speculum to help the horse keep his mouth open during treatment. It looks very much like a headstall, with the exception of an adjustable mouthpiece that sits just inside the horse’s mouth with two metal plates for the upper and lower front teeth to rest on. These plates are level in themselves, so as the horse opens his mouth, any imbalance in the incisors will then be shifted to the molars. This makes it appear as though the deviation in the horse’s mouth originates there, because the TMJ has approximately 1/4” of “play” in it. This is why it is so critical to start with the incisors. The angle of the TMJ is exactly opposite to that of the molar table (contacting surfaces of the upper and lower teeth). All of these factors, taken into consideration, are what amount to anatomical balance, according to the individual horse. Getting aligned

Many of today’s equine dentists apply centric, or centered, alignment to the mouth. That is, they apply a static “leveling” standard to every equine mouth they treat. The focus currently common among dentists is occlusion. This simply means the meeting, or flush contact, of upper and lower tooth-on-tooth surfaces. However, because of the adaptable nature of equine tooth eruption, occlusion is present in all horses even before dentistry is applied. Horses already have centric occlusion present in their mouths when they show up at the dentist. It should then be up to the dentist to anatomically align the mouth, so that it fits the individual to its optimal range.

The focus should actually be on re-establishing proper biomechanics in the horse’s jaw. The motion of the jaw is 50% of the total mechanics. The tongue rotates in the opposite direction to the jaw. The combined efforts of the two are what move the food bolus from the front of the mouth to the back. If the length and angle of the incisors vary from what nature intended, it causes the jaw to rotate in a more vertical motion – up and down, rather than side to side.

How do we check the biomechanics of the jaw? Rather than pushing the closed jaw from one side to the other, which most people are familiar with, you can properly check the horse by cueing it to contract its own massitors (muscles that control the jaw). This demonstrates the true biomechanical range of the jaw. (Consider this: if pushing the closed jaw worked, human dentists would use this method rather than the traditional carbon paper and “bite” technique to check the surface-to-surface contact of our teeth.) An equine dentist cues the horse by inserting his fingers into the side of the mouth, initiating a chewing motion reflex response. Numerous human dentists have told me that all animals maintain a state of disclusion, or non-contact of teeth, while at rest or engaged in activities other than eating. If the teeth were in contact while moving, their surfaces would be damaged. So occlusion, or mastication of food, is only accomplished when the individual contracts his massitors.

Balance is achieved by starting with the equilibration of the incisors. Generally, a primary angle of adjustment is necessary. If there is a great deal of change to be made, it should be done gradually over time, as it is in humans. After all, the problem took a long time to develop; it should take a while to fix.

I don’t believe an equine dentist needs power equipment any more than a farrier needs a grinder to balance a foot. As it is, most equine dental tools are not ergonomically designed to fit in the horse’s mouth, let alone help balance it. I’ve spent three years designing hand instruments that ergonomically fit the horse as well as the practitioner. This results in bloodless horse dentistry and less discomfort afterwards.