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Maxillary left second premolar
A two-cusped premolar similar to the first premolar, with cusps closer in size and usually a single root.
- FDI
- 25
- Universal
- 13
- Palmer
- UL5
- Roots
- Usually one
- Root canals
- One, sometimes two
- Eruption
- About 10–12 years
Form and anatomy
The crown is smaller and more rounded than that of the first premolar, and its two cusps, buccal and palatal, are nearly equal in height. The buccal cusp is less pointed and centred over the root, and the mesial crown concavity typical of the first premolar is usually absent. The central groove is shorter, and more supplemental grooves give the occlusal surface a wrinkled look. There is normally a single root, broad buccopalatally and flattened on its mesial and distal sides, often with shallow longitudinal grooves. Inside it, a single canal is most common, but two canals, which may join before the apex, are found in a large share of teeth. Because the crowns of the two maxillary premolars look alike, the relative cusp heights and the mesial concavity are the usual clues for telling them apart.
Function
Crushing and grinding food.
Clinical relevance
Usually one canal, but two canals occur in a substantial minority.
Canal counts in a study
| Canals | Observed frequency |
|---|---|
| 1 | 66.7% |
| 2 | 31.3% |
| 3 | 2.0% |
Teeth examined: 147. Adults from a radiology practice in Toulouse, France; left and right teeth combined. CBCT, 200 µm voxels Canal count observed on CBCT; small canals may go undetected.
These are sample frequencies, not universal probabilities. Population, sampling and method affect the results. Root count and canal configuration are different measurements. The 3D model shows one configuration; it does not change with these percentages.
Monsarrat et al. (2016), Table 2
Neighbouring teeth
- Mesial neighbour
- Maxillary left first premolar
- Distal neighbour
- Maxillary left first molar
- Same tooth, other side
- Maxillary right second premolar
- Opposing tooth
- Mandibular 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.