In total, humans are provided with eight incisor teeth or simply incisors (Latin: dentes incisivi). Four incisors are located in the middle of each row (upper or lower) of teeth. Therefore, four incisors are located in the maxillae and four in the mandible. 

Incisors are divided into two subdivisions, named the medial or central and lateral incisors, depending on how far they are located from the midline of the jaw. Each row contains two central and two lateral incisors.

Incisors help to cut, pluck and bite the food. They also help to hold the food in the oral cavity. For this reason, the crown of these teeth has a chisel-shaped form, and its lateral surface is triangular. Actually, the word “incisors” derives from the Latin word “incidere”, and it means “to cut”.

Incisors have only one long and conical root.

The incisors are the first permanent teeth to appear. Usually, mandibular incisors erupt between 6 to 7 years and the maxillary incisors between 6 to 8 years.

NOTE: the Universal Tooth Numbering System for secondary dentition is used for incisor teeth numbering. Find out what it is and which are the two other systems in the article about the dental notation systems.