The function of this premolar is assist the mandibular first molar during mastication, commonly known as chewing.

The groove pattern is shaped like a “Y” with the tail pointed to the lingual and placed between the distolingual and mesiolingual cusps one third of the distance form the distal to the mesial.

Viewed from the mesial or distal the buccal height of contour is in the gingival third of the tooth.

In the universal system of notation, the permanent mandibular premolars 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 second premolar is known as "45", and the left one is known as "35".

It is a very common condition in orthodontics for a patient to have one or both mandibular second premolars congenitally absent.