What is the Difference Between First and Second Premolar?

The main differences between first and second premolars are found in their structure, cusps, and root characteristics. Here is a comparison of the two types of premolars:

First Premolar:

• Sharper and more prominent cusps, with the buccal cusp being significantly larger than the palatal cusp.
• Have two root canals.
• Found just next to the canine on either side of the jaw.
• Maxillary first premolars have a unique prominent mesial crown concavity just cervical to the contact area.
• The mesial and distal sides of maxillary premolar crowns converge more noticeably from the contact, making the cervical portion of the crown appear relatively narrower.

Second Premolar:

• More rounded and shorter cusps, similar in size and height.
• Roots are smaller and have a larger root-to-crown ratio.
• Found between the first premolar and the first molar on either side of the jaw.
• Maxillary second premolars have one root with longitudinal midroot depressions located in the furcation area.
• The lingual cusp of the mandibular second premolar follows the general rule, where the distal contact is more cervical than the mesial contact area.

Premolars play an essential role in the proper tearing of food during mastication.

Comparative Table: First vs Second Premolar

The first and second premolars are teeth located between the canines and molars in a human mouth. They are divided into first and second premolars based on their position and structure. Here is a table highlighting the differences between the first and second premolars:

The first premolar has sharper and more prominent cusps, while the second premolar has rounded and smaller cusps. The right maxillary first premolar is designated as 4, and the left one is 13. In contrast, the right maxillary second premolar is 2, and the left one is 5, while the others are 6 and 7. The right mandibular first premolar is denoted as 28, and the left one is 21. The right mandibular second premolar is 29, and the left one is 20. The right third mandibular premolar is 30, and the left one is 31.