Incorrect occlusion surface of the teeth arcs may lead to problems in the horse’s overall balance. If there is correct contact on one side of the mouth but not on the other this will cause an overloading of the TMJ and result in the horse putting his head into a position he finds less painful. This in turn, however, means that the head is moved away from the correct balance axis. Thus one side of the horse is overloaded compared to the other and the long term results are riding problems that may include head shaking, head tilted to one side, not stopping, difficulty in putting the bridle on, high head carriage, rearing, running backwards, running away, bucking, over-bending, pointing of the nose, bad transitions, difficulty in changing paces, a stiff neck, a hard mouth, tongue problems, stiffness of the shoulders, forging, and overstepping, hollow back, lack of impulsion from behind, better movement on one side compared to the other, atlas (poll) problems, bleeding and excessive salivation.

Other problems may include loss of weight, eating too fast or too slowly, dropping food, washing food in water before eating, dentition fever, cribbing, biting, nasal discharge, smell emanating from the mouth or nose, facial bumps or lumps, eye discharge, holding the head to one side to prevent food dropping, intermittent lameness, temperament changes, a dispirited disposition: owners should pay attention to the first signs of any of these symptoms so as to avoid trouble in the future and create bad habits in both horse and rider. Balance is critical to the sports horse and a correctly balanced mouth can assist the horse’s overall balance. Bits and all mechanical devices should be fitted to the head with considerable thought being given to the animal’s basic anatomy and comfort.