Incisor

An incisor is a type of tooth located at the front of the dental arches. In a full adult dentition there are eight incisors—four in each jaw: the central incisor and the lateral incisor on each side. In children (primary dentition) there are four incisors per arch. Incisors play a primary role in cutting food and shaping the smile, and they also assist with speech.

Anatomy: Incisor crowns are narrow with a sharp incisal edge designed for shearing. The surfaces include labial (facial) and lingual (tongue-side) surfaces, as well as mesial and distal surfaces toward adjacent teeth. Most incisors have a single root, though root length and contour vary between the central and lateral incisors and between maxillary and mandibular arches. Enamel covers the crown, with dentin beneath and a pulp chamber within the tooth.

Eruption and development: Primary incisors erupt roughly from six to twelve months of age; permanent incisors emerge later, with central incisors typically around seven to eight years and lateral incisors around eight to nine years, though timing can vary. The eruption order influences early occlusion and spacing.

Function and clinical relevance: Incisors guide the bite and support proper speech and aesthetics. They are common sites for wear, chipping, caries, and restorative treatments such as fillings, veneers, or crowns. Variations in shape or alignment, such as shovel-shaped incisors in some populations, can affect both appearance and dental function. Regular dental care emphasizes maintaining incisor health as part of overall oral hygiene.