The typical adult mouth has 32 teeth: eight incisors, four canines, eight premolars, and 12 molars (including four wisdom teeth). The canines, also called cuspid or eye-teeth, are the longest teeth, located in the corners of the mouth.

Canines are the most stable teeth, and are specially modified to tear food easily. While some other animals — like wild boars and walrus — have exaggerated canines, humans’ are only slightly pronounced. Although our canines are not particularly large, humans have retained an oversized canine root, which causes a bulge in the upper jaw that supports the corner of the lip.

The maxillary canines (located in the upper jaw, just behind the front teeth) are the second most commonly impacted teeth, a condition in which the tooth does not fully break through the gum. This occurs in about one to two percent of the population. If an impacted tooth is problematic, removal is the most common treatment.