COMMON DENTAL ABNORMALITIES
HOOK: This occurs when the upper jaw is slightly forward of the lower jaw creating a situation where the first upper premolar does not meet the lower premolar and hence the front part of the tooth grows long and sharp. Left unattended this hook can grow into the lower jaw causing intense pain and infection. this abnormality is often seen in horses with an overbite (parrot mouth) and is sometimes accompanied by lower ramps at the back of the jaw.
RAMP: A ramp is basically the same thing as a hook, but its on the lower jaw. Ramps can be associated with the first lower premolar (#6) or the last lower molar (#11). They can cause the same complications as hooks.
STEP MOUTH: This occurs when one cheek tooth is either missing or is completely overpowered by the opposing cheek tooth. This abnormality allows the opposing or dominant tooth to grow into the gap left by the missing or weak tooth creating a situation where the lower jaw is unable to move forward or backward. This inability to move makes it nearly impossible for the horse to break at the poll and hence collection is unable to be achieved.
WAVE MOUTH: This abnormality is similar to a step mouth, but with more teeth involved. There are both high and low points on each arcade creating a situation where the movement of the jaw is severely inhibited in all directions causing difficulty chewing as well as difficulty with collection and performance.
SHEAR MOUTH: This occurs when the horse is not chewing evenly on both sides of the mouth causing uneven wear patterns in both the incisors and the cheek teeth. The points associated with a shear mouth can be excessively sharp and cause severe damage to the delicate tissues of the cheeks and tongue.
RAMP: A ramp is basically the same thing as a hook, but its on the lower jaw. Ramps can be associated with the first lower premolar (#6) or the last lower molar (#11). They can cause the same complications as hooks.
STEP MOUTH: This occurs when one cheek tooth is either missing or is completely overpowered by the opposing cheek tooth. This abnormality allows the opposing or dominant tooth to grow into the gap left by the missing or weak tooth creating a situation where the lower jaw is unable to move forward or backward. This inability to move makes it nearly impossible for the horse to break at the poll and hence collection is unable to be achieved.
WAVE MOUTH: This abnormality is similar to a step mouth, but with more teeth involved. There are both high and low points on each arcade creating a situation where the movement of the jaw is severely inhibited in all directions causing difficulty chewing as well as difficulty with collection and performance.
SHEAR MOUTH: This occurs when the horse is not chewing evenly on both sides of the mouth causing uneven wear patterns in both the incisors and the cheek teeth. The points associated with a shear mouth can be excessively sharp and cause severe damage to the delicate tissues of the cheeks and tongue.
INCISOR ABNORMALITIES
When the horse is at rest with the mouth closed, the incisor teeth meet and the cheek teeth do not meet. As the horse chews the lower jaw moves side to side, sliding the incisors apart and engaging the cheek teeth for the power stroke of the chewing cycle. If the incisors are not properly aligned, the cheek teeth can not meet properly thereby decreasing the power of the chewing stroke and inhibiting the abiity of the horse to digest food. Correction of incisor abnormalities is essential to proper dental maintence.
SEVERE STEP MOUTH
The red circle is pointing out a severe lower #6 step that has actually worn the upper #6 tooth competely away. The last upper cheek tooth (#11) has also grown into a severe step that has completely eroded the lower #11 molar away. There is also damage to the incisor teeth. This horse would have had a very difficult time chewing and likely would have been quite thin.
LOWER #11 RAMP
Although the photo labels this abnormality as a hook, lower "hooks" are generally refered to as ramps. In this case the ramp has worn a hole through the corresponding upper #11 molar and has literally grown into the gum. This would have cause severe pain when chewing and also would have caused the jaw to "lock" . In this "locked" state the lower jaw is unable to slide foreward. In order for a horse to break at the poll and collect, the lower jaw must be able to slide foreward, so this horse would not have been able to collect.
WAVE MOUTH
This image is of a lower jaw by itself. This represents a severe wave complex that would have severely inhibited all aspects of the normal function of the mouth. This is a very difficult contidition to correct as the teeth can not just be leveled out. Aggressive leveling of these teeth would create a situation where the cheek teeth do not meet at all and therefore the horse is completely unable to chew. Frequent dentistry over several years would be required to correct and maintain this mouth. This condition could have been prevented with routine dental check-ups and routine dental floating.
THE EQUINE MOUTH BEFORE AND AFTER DENTISTRY
In this diagram the skull on the left represents a horse with a "normal" mouth before dentistry. There are sharp enamel points on the outside (buccal) of the upper cheek teeth and on the inside (lingual) of the lower cheek teeth. These points cause problems in several ways. These points can and do erode the soft sensitive tissues of the cheeks and tongue causing very painful ulcers. The points also inhibit the proper movement of the jaw, decreasing the ability of the horse to properly chew his feed. The lack of a bit seat (rounding of the first cheek tooth) can lead to the inside of the cheek being pinched between the first cheek teeth and the bit, leading to poor perforance under saddle. The skull on the right has had these issues addressed through proper dentistry.