15/01/2021
// Friday Fact - Dentition and Mouth Pain //
The horse's comfort, especially when ridden, can be profoundly affected by its dentition. Put simply, horses have not evolved to accommodate a bit (of whatever volume) in the mouth, so the intra-oral presence of the bit requires the tongue to move into a more-or-less abnormal position. This, and the need in some disciplines to maintain contact, can reduce the horse's own ability to keep its cheek and tongue away from a sharp element of its dental arcade. The result is resistance and a narrowing of the margin that represents neutral contact. Essentially, the horse becomes more difficult to maintain in speed, line and posture.
Mouth pain may also be associated with heavy-handed riding or inappropriate fear. For example, some jointed bits can cause pinching between the second premolar and the labial commissures. Wolf teeth, especially those with loose roots and cusps that are directed towards the seat of the bit, may make the horse reluctant to accept the bit and may trigger it to reef the reins out of the rider's hands. This can rapidly escalate into head-tossing. The reinforcing nature of this activity seems obvious and is likely to be most profound if the rider usually yields.
In the event of a horse fighting the bit, some veterinarians and equine dentists are prepared to remove an appreciable portion of the second premolar to create a 'bit seat' or 'cheek seat', which is supposed to improve comfort in this part of the mouth. While one study reported improved athletic performance in most horses after the creation of bit sseats, an abiding question is whether a simple change of riding technique or bit (e.g. to an unjointed design) would have been equally effective.
(Excerpt from the book 'Equitation Science', p. 225)