As with all incisors, their function is for shearing or cutting food during mastication, commonly known as chewing.

In the universal system of notation, the deciduous mandibular lateral incisors are designated by a letter written in uppercase.

In the universal system of notation, the permanent mandibular lateral incisors are designated by a number.

In the Palmer notation, a number is used in conjunction with a symbol designating in which quadrant the tooth is found.

The international notation has a different numbering system than the previous two, and the right permanent mandibular lateral incisor is known as "42", and the left one is known as "32".