TMJ – Temporal Mandibular Joint
TMD – Temporal Mandibular Joint Disfunction
The TMJ or Temporal Mandibular Joint is located at the upper rear of the mandible (better known as the lower jaw) located in the condiles of the skull . This is the point where the jaw hinges in the skull. The TMJ consists of bone,cartlage and very sensitive nerves in the condiles of the skull and when abused or damaged causes very severe pain while chewing or with jaw movement. The nerves affected heal very slowly after being damaged. Left without proper dental balance the horse may even have permanent nerve damage. The Masater Muscles ( the large powerful jaw muscles on both sides of the jaw) are able to exert a massive amount of pressure that is used in the chewing process. Rostal (front) and Caudal (rear) hooks , Ramps, Protubent (over long) molars keep the horse from closing its mouth fully thus hindering proper closure and mouth balance. The pressures placed on the temporo mandibular joint effects the integerity of the joint by damaging the cartlage and nerves creating pain while chewing or movement of the TMJ. Equine Dentistry uses the term full mouth balance which means that the jaw teeth or molars can close fully without the hinderance of hooks or ramps or over long teeth allowing a good level chewing surface at the desired 10 to 15 degree angle and the front teeth or incissors that do not hinder the mouth closure desired for proper molar contact. When the mouth closes properly and the desired chew is accomplished we say the horses mouth is in occlusion and is able to masticate (grind) its feed properly without having the undesired pressure and damage to the TMJ. A horse suffering from TMJ damage is said to have TMD-(Temporal Mandibular Joint Disfunction) and may never entirely recover from the damage caused by the malocclusions that have not been properly corrected or maintained. It is very important to have an Equine Dentist check for dental problems early in the horses life and exercise yearly maintenance to insure a good chew, lessen the chance of collic, get better food value, lessen pain, save on feed, and enhance the health and safety of the horse as well as the rider.