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Mandibular left second premolar
A premolar with a better-developed lingual portion than the first premolar, often with two lingual cusps.
- FDI
- 35
- Universal
- 20
- Palmer
- LL5
- Roots
- One
- Root canals
- Usually one
- Eruption
- About 11–12 years
Form and anatomy
The crown occurs in two main forms. The more common three-cusp form has one buccal and two lingual cusps, the mesiolingual larger than the distolingual, with a Y-shaped groove pattern on the occlusal surface. The two-cusp form has a single lingual cusp and an H- or U-shaped groove pattern. Either way the lingual part of the crown is much better developed than in the first premolar, and the crown looks more square from the occlusal side, with cusps closer in height. The single root is larger and longer than the first premolar's and usually carries one canal. Congenital absence of this tooth is among the most common in the permanent dentition, often discovered when a primary second molar is retained. Its apex is a common landmark for locating the mental foramen on radiographs.
Function
Crushing and grinding food.
Clinical relevance
The mental foramen commonly lies near the apices of the mandibular premolars — relevant to surgery and anaesthesia.
Neighbouring teeth
- Mesial neighbour
- Mandibular left first premolar
- Distal neighbour
- Mandibular left first molar
- Same tooth, other side
- Mandibular right second premolar
- Opposing tooth
- Maxillary left second premolar
This text is a draft and has not yet been reviewed by a dental professional. Educational reference only, not for diagnosis or treatment.