Irregular Wear of the Dentition in Large Animals
Except for pigs, most large animals have an intermandibular space that is narrower than the intermaxillary space; ie, they are anisognathic. In horses, this, 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. In cattle and sheep, because the temporomandibular joint affords greater lateral movement of the mandible, such irregularities do not develop as frequently. Extreme forms of disease, however, are seen in all species and may be influenced by other skeletal deformities of the face or accompanying infections (eg, Actinomyces sp). Gross shear mouth may result, with exaggerated obliquity of the molar tables. It may be seen in older horses, and treatment is usually unsatisfactory. Dental care should be supplemented by special diets.
Enamel points are best treated by regular dental equilibration in horses (ie, floating). This should be done twice annually while the permanent dentition is developing; at the same time, retained caps should be removed if they cause oral ulceration or discomfort.
Wave mouth, step mouth, and rostral and caudal hooks are dental overgrowths caused by uneven wear of the teeth and are the result of local pain, dental or jaw malalignment, or missing or damaged teeth. In time, this can lead to abnormal spaces forming between the teeth (diastema), which have been shown to cause feed entrapment and secondary gum and socket disease (ie, periodontitis). Such conditions are best prevented by regular, routine dental prophylaxis. Once dental wear abnormalities are severe, results of dental procedures are usually incomplete. Although occlusal surfaces may be realigned, dental care needs to be supplemented by special dietary regimens.