By the age of 18, the average adult has 32 teeth. The top jaw, or maxilla, has 16 teeth, numbered #1-16. The mandible, or bottom jaw, also has 16 teeth, numbered #17-32. Each tooth in the mouth has a specific name and function. The teeth in the front of the mouth (incisors, canine, and bicuspid teeth) are ideal for grasping and biting food into smaller pieces. The back teeth (molar teeth) are used to grind food up into a consistency suitable for swallowing. The average mouth is made to hold only 28 teeth.