Humans are provided with eight incisor teeth (or simply incisors; Latin: dentes incisivi). Four incisors are located in the middle of each teeth row. Therefore, four incisors are located in the maxillae (7 - 10) and four in the mandible (23 - 26).
Depending on how far the incisors are located from the midline of the jaw, they are divided into two subdivisions - medial or central and lateral incisors. The medial incisor is the most centrally located tooth. Each row contains two central and two lateral incisors.
Incisors help to cut, pluck and bite the food. Also, they help to hold the food in the oral cavity. For this reason, the crown of these teeth has a chisel-shaped form, and their lateral surfaces (mesial and distal) are triangular. Moreover, the word “incisors” derives from the Latin word “incidere”, and it means “to cut.”
The incisors have only one long and conical root.
These teeth are the first permanent teeth to erupt. Usually, the 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 in the 3D model for incisor teeth numbering. Find out what it is and which are the two other systems in the article about the dental notation systems!