Universal tooth 21
Tooth 21: Lower Left First Premolar
In the Universal Numbering System, tooth 21 is the lower left first premolar (mandibular left first premolar). Its FDI (ISO 3950) designation is 34 and its Palmer designation is 4 in the lower left quadrant. It is a premolar in the lower arch with typically 1 root.
- Universal
- 21
- FDI / ISO 3950
- 34
- Palmer
- 4
- Type
- Premolar
- Arch & side
- lower, left
- Typical roots
- 1
Lower left · Permanent
Lower Left First Premolar
Mandibular Left First Premolar
- Universal
- 21
- FDI / ISO
- 34
- Palmer
- 4
- Type: Premolar
- Arch & side: Lower (mandibular), left
- Typical roots: 1 (varies between individuals)
Full conversion table
Print / save as PDFUpper right
| Tooth | Universal | FDI | Palmer |
|---|---|---|---|
| 8 | 11 | 1 | |
| 7 | 12 | 2 | |
| 6 | 13 | 3 | |
| 5 | 14 | 4 | |
| 4 | 15 | 5 | |
| 3 | 16 | 6 | |
| 2 | 17 | 7 | |
| 1 | 18 | 8 |
Upper left
| Tooth | Universal | FDI | Palmer |
|---|---|---|---|
| 9 | 21 | 1 | |
| 10 | 22 | 2 | |
| 11 | 23 | 3 | |
| 12 | 24 | 4 | |
| 13 | 25 | 5 | |
| 14 | 26 | 6 | |
| 15 | 27 | 7 | |
| 16 | 28 | 8 |
Lower left
| Tooth | Universal | FDI | Palmer |
|---|---|---|---|
| 24 | 31 | 1 | |
| 23 | 32 | 2 | |
| 22 | 33 | 3 | |
| 21 | 34 | 4 | |
| 20 | 35 | 5 | |
| 19 | 36 | 6 | |
| 18 | 37 | 7 | |
| 17 | 38 | 8 |
Lower right
| Tooth | Universal | FDI | Palmer |
|---|---|---|---|
| 25 | 41 | 1 | |
| 26 | 42 | 2 | |
| 27 | 43 | 3 | |
| 28 | 44 | 4 | |
| 29 | 45 | 5 | |
| 30 | 46 | 6 | |
| 31 | 47 | 7 | |
| 32 | 48 | 8 |