Supernumerary Teeth in the Horse

Abstract

Supernumerary teeth are relatively uncommon occurrences in horses and, when present, usually occur in the permanent incisors or cheek teeth, with supernumerary “wolf” and canine teeth rarely diagnosed. The presence of supernumerary incisors which are usually of normal morphology (ie, termed supplemental supernumerary teeth) can cause displacements of the normal incisors with development of diastemata and periodontal disease. In addition, overgrowths will occur on incisors that are not in occlusal contact. If rostrally (labially) displaced onto the gingiva, supernumerary incisors can be extracted, but when present palatally to the normal incisor arcade, extraction is difficult and should be avoided if possible. Supernumerary cheek teeth may be of normal morphology or may be connated (ie, are large structures composed of a number of vestigial teeth). They most commonly occur at the caudal aspect of the maxillary cheek teeth rows. Their presence may give rise to a variety of clinical problems, such as malocclusion, food pocketing, and deep periodontal disease that may even lead to maxillary sinusitis. Overgrowths can occur on supernumerary cheek teeth and may cause soft tissue trauma to the cheeks and tongue which may render normal mastication difficult and, in some cases, impossible. These teeth may also result in eruption abnormalities from mechanical obstruction. In the presence of periodontal disease, diastemata, or sinusitis, extraction of the supernumerary tooth is indicated. If possible, this is best performed per os. Where significant periodontal disease is not present, reduction of overgrowths on the unopposed supernumerary cheek teeth is indicated.