canine tooth, any of the four teeth, one on each side of the upper and lower jaws, situated between the lateral incisor and the first premolar. The canine teeth are larger and stronger than the incisors and have characteristics of both anterior and posterior teeth. Canines are the longest rooted teeth in the dentition, and serve as a turning point and transition between anterior and posterior teeth. They project beyond the occlusal level of the other teeth in both arches. Their roots sink deeply into the bones, causing marked prominences on the alveolar arch. The upper (maxillary) canine teeth, or eyeteeth, are larger and longer than the mandibular canines and have a distinct basal ridge. The lower (mandibular) canine teeth, or stomach teeth, are situated nearer the midline than the maxillary canines, and their summits (cuspal edges) correspond to the intervals between the upper canines and incisors. The crowns of the canines are very large and conic and taper to blunted points or cusps. The primary canines lie between the primary lateral incisors and primary first molars and erupt about 16 to 20 months after birth, whereas the permanent canines erupt during the eleventh or twelfth year of life. The canines serve to powerfully grasp, tear, and cut food in preparation for further mastication.
