# Which tooth is number 15?

Answer: In the Universal Numbering System, tooth 15 is the upper left second molar (maxillary left second molar). Its FDI (ISO 3950) designation is 27 and its Palmer designation is 7 in the upper left quadrant. It is a molar in the upper arch with typically 3 roots.

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Answer intent ID: `tooth-number-15`
Cluster: Tooth numbering reference
Last verified: 2026-07-08
Reviewer: see source page

## Direct answer

In the Universal Numbering System, tooth 15 is the upper left second molar (maxillary left second molar). Its FDI (ISO 3950) designation is 27 and its Palmer designation is 7 in the upper left quadrant. It is a molar in the upper arch with typically 3 roots.

## Query patterns

- Which tooth is number 15?
- Tooth 15: Upper Left Second Molar
- Which tooth is 15?
- What is tooth number 15 in FDI and Palmer notation?
- Which tooth is FDI 27?
- What is FDI 27 in Universal numbering?
- FDI 27 to Universal tooth number
- ISO 3950 tooth 27
- Which tooth is Palmer 7 Upper Left?
- Palmer 7 Upper Left to Universal
- Upper Left Palmer 7 tooth
- UL Palmer 7 permanent tooth
- Upper Left Second Molar tooth number
- Universal 15 FDI 27 Palmer 7
- which tooth is number 15?
- tooth 15
- tooth number 15
- universal tooth 15
- adult tooth 15
- upper left second molar
- maxillary left second molar
- fdi 27

Source citations:
- `TOOTH-1` American Dental Association — Universal Numbering System. <https://www.ada.org/publications/ada-news/2020/november/how-to-count-teeth-numbering-systems>
- `TOOTH-2` ISO 3950:2016 — Dentistry, designation system for teeth and areas of the oral cavity (FDI two-digit). <https://www.iso.org/standard/68292.html>
- `TOOTH-3` FDI World Dental Federation — two-digit notation. <https://www.fdiworlddental.org/>

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## Supporting public URLs

- [/tools/tooth-numbering-chart](https://dentovio.com/tools/tooth-numbering-chart)
- [/tools/fdi-to-universal-converter](https://dentovio.com/tools/fdi-to-universal-converter)
- [/tools/palmer-notation-converter](https://dentovio.com/tools/palmer-notation-converter)
- [/tools/tooth-numbering-chart/tooth-15](https://dentovio.com/tools/tooth-numbering-chart/tooth-15)

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