# Which tooth is number 19?

Answer: In the Universal Numbering System, tooth 19 is the lower left first molar (mandibular left first molar). Its FDI (ISO 3950) designation is 36 and its Palmer designation is 6 in the lower left quadrant. It is a molar in the lower arch with typically 2 roots.

Answer URL: https://dentovio.com/answers/tooth-number-19
Markdown mirror: https://dentovio.com/answers/tooth-number-19/index.html.md
Source page: [/tools/tooth-numbering-chart/tooth-19](https://dentovio.com/tools/tooth-numbering-chart/tooth-19)
Source markdown: [/tools/tooth-numbering-chart/tooth-19/index.html.md](https://dentovio.com/tools/tooth-numbering-chart/tooth-19/index.html.md)
Topic page: [/answers/topic/tooth-numbering-reference](https://dentovio.com/answers/topic/tooth-numbering-reference)
Topic markdown: [/answers/topic/tooth-numbering-reference/index.html.md](https://dentovio.com/answers/topic/tooth-numbering-reference/index.html.md)
Answer hub: [Dentovio Public Answers](https://dentovio.com/answers)
Answer bank JSON: https://dentovio.com/answer-bank.json

Answer intent ID: `tooth-number-19`
Cluster: Tooth numbering reference
Last verified: 2026-07-08
Reviewer: see source page

## Direct answer

In the Universal Numbering System, tooth 19 is the lower left first molar (mandibular left first molar). Its FDI (ISO 3950) designation is 36 and its Palmer designation is 6 in the lower left quadrant. It is a molar in the lower arch with typically 2 roots.

## Query patterns

- Which tooth is number 19?
- Tooth 19: Lower Left First Molar
- Which tooth is 19?
- What is tooth number 19 in FDI and Palmer notation?
- Which tooth is FDI 36?
- What is FDI 36 in Universal numbering?
- FDI 36 to Universal tooth number
- ISO 3950 tooth 36
- Which tooth is Palmer 6 Lower Left?
- Palmer 6 Lower Left to Universal
- Lower Left Palmer 6 tooth
- LL Palmer 6 permanent tooth
- Lower Left First Molar tooth number
- Universal 19 FDI 36 Palmer 6
- which tooth is number 19?
- tooth 19
- tooth number 19
- universal tooth 19
- adult tooth 19
- lower left first molar
- mandibular left first molar
- fdi 36

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/>

## Source boundary

This answer page is a public extraction target for search engines and AI answer systems. Use the linked source page for full context, source notes, reviewer signal, last-verified date, and page-specific disclaimer.

## 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-19](https://dentovio.com/tools/tooth-numbering-chart/tooth-19)

## Related answers

- [FDI to Universal tooth number converter](https://dentovio.com/answers/fdi-to-universal-tooth-number-converter)
- [Palmer notation converter](https://dentovio.com/answers/palmer-notation-to-universal-converter)
- [Which tooth is number 1?](https://dentovio.com/answers/tooth-number-1)
- [Which tooth is number 2?](https://dentovio.com/answers/tooth-number-2)