Types of Teeth and Their Functions

There are 4 types of teeth in the oral cavity:

  • Incisors – The four front teeth in both the upper and lower jaws are called incisors.  Their primary function is to cut food.  The two incisors on either side of the midline are known as central incisors.  The two adjacent teeth to the central incisors are known as the lateral incisors.  Incisors have a single root and a sharp incisal edge.
  • Canines – There are four canines in the oral cavity. Two in the maxillary arch and two in the mandibular area.  They are behind and adjacent to the lateral incisors.  Their main function is to tear food.  They have a single, pointed cusp and a single root.  They have the longest root of any tooth.  They also serve to form the corners of the mouth.
  • Premolars (Bicuspids) – These teeth are located behind and adjacent to the canines and are designed to crush food.  There are eight premolars in the oral cavity.  There are two in each quadrant of the mouth.  The one closest to the midline is the first premolar and the one farthest from the midline is the second premolar.  These teeth can have 3-4 cusps.  The maxillary first premolar has two roots, and the remaining premolars have a single root.  There are no premolars in the primary dentition.
  • Molars – The most posterior teeth in the mouth are the molars.  They have broader and flatter surfaces with 4-5 cusps.  They are designed to grind food.  Molars typically have two roots, although the maxillary first molar (behind the second premolar) has three roots.  There are 12 molars in the permanent dentition with three in each quadrant of the mouth.  They are named starting with closest to the midline as first molars, second molars and third molars.  Although, some people do not fully develop the third molars.  Third molars are often referred to as wisdom teeth.  The primary dentition only contains eight molars.