Merck Manual

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Professional Version

Irregular Wear of the Dentition in Horses


Jack Easley

, DVM, MS, DAVDC (Equine), DABVP (EQ), Easley Equine Dentistry, Shelbyville, KY

Reviewed/Revised Feb 2024

Most large animals (except pigs) have an intermandibular space that is narrower than the intermaxillary space. In horses, this relative overlap of the upper teeth beyond the buccal margins of the lower teeth, together with limited natural movement of the mandible, results in the development of enamel points on the buccal edges of the upper arcades and on the lingual edges of the lower arcades.

Enamel points are best treated by regular dental equilibration (ie, teeth floating). Dental equilibration should be done twice annually while the permanent dentition is developing; during this procedure, retained caps should be removed if they cause oral ulceration or discomfort.

"Wave mouth", "step mouth", and rostral and caudal hooks are dental overgrowths due to uneven wear of the teeth. They are the result of local pain, malocclusion, or missing or damaged teeth. In time, these conditions can lead to the formation of abnormal spaces between the teeth (diastemata), which cause feed entrapment and secondary periodontitis. Such conditions are best prevented by regular, routine dental prophylaxis. If dental wear abnormalities become severe, dental procedures are usually not fully effective as treatment. Although occlusal surfaces may be realigned, dental care may need to be supplemented by special dietary regimens.

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