# Which tooth is number 28?

Answer: In the Universal Numbering System, tooth 28 is the lower right first premolar (mandibular right first premolar). Its FDI (ISO 3950) designation is 44 and its Palmer designation is 4 in the lower right quadrant. It is a premolar in the lower arch with typically 1 root.

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Answer intent ID: `tooth-number-28`
Cluster: Tooth numbering reference
Last verified: 2026-07-08
Reviewer: see source page

## Direct answer

In the Universal Numbering System, tooth 28 is the lower right first premolar (mandibular right first premolar). Its FDI (ISO 3950) designation is 44 and its Palmer designation is 4 in the lower right quadrant. It is a premolar in the lower arch with typically 1 root.

## Query patterns

- Which tooth is number 28?
- Tooth 28: Lower Right First Premolar
- Which tooth is 28?
- What is tooth number 28 in FDI and Palmer notation?
- Which tooth is FDI 44?
- What is FDI 44 in Universal numbering?
- FDI 44 to Universal tooth number
- ISO 3950 tooth 44
- Which tooth is Palmer 4 Lower Right?
- Palmer 4 Lower Right to Universal
- Lower Right Palmer 4 tooth
- LR Palmer 4 permanent tooth
- Lower Right First Premolar tooth number
- Universal 28 FDI 44 Palmer 4
- which tooth is number 28?
- tooth 28
- tooth number 28
- universal tooth 28
- adult tooth 28
- lower right first premolar
- mandibular right first premolar
- fdi 44

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-28](https://dentovio.com/tools/tooth-numbering-chart/tooth-28)

## Related answers

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- [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)