Tooth number 24 is the lower left central incisor, a permanent (adult) tooth. In the FDI (ISO 3950) system it is 31, and in Palmer notation it is ┌1.
Tooth #24 at a glance
| Universal (US) | 24 |
| FDI / ISO 3950 | 31 |
| Palmer | ┌1 |
| Name | Lower left central incisor |
| Type | Central incisor (adult tooth) |
| Jaw | Lower (mandible) |
| Side | Patient’s left |
| Comes in | 6-7 yrs |
| Roots | 1 |
| Root canals (usual) | 1, sometimes 2 |
| Chewing surface | An incisal edge |
Where it is and what it does
It sits in the lower jaw on the patient’s left side, right at the front, next to the midline. Incisors are cutting teeth. Their thin, flat edges bite through food, and they matter a lot for speech and for how a smile looks.
Neighbouring and related teeth
- Across the midline: Tooth number 25, the lower right central incisor
- Behind it: Tooth number 23, the lower left lateral incisor
- The matching tooth in the upper jaw: Tooth number 9
- Replaces: Baby tooth O, the baby lower left central incisor
Common dental work on this tooth
Front teeth are often chipped or knocked. Common treatments include bonding (tooth-coloured filling material), veneers, crowns and, after an injury that reaches the nerve, a root canal.
Questions
What tooth is number 24?
Tooth number 24 is the lower left central incisor. Numbers 1 to 32 are used for adult teeth in the Universal system used in the United States, starting with the upper right wisdom tooth.
What is tooth number 24 in the FDI and Palmer systems?
In FDI it is 31, said digit by digit (“three-one”). The first digit is the quadrant and the second is the position from the midline. In Palmer notation it is ┌1.
When does tooth 24 come in?
Usually at about 6-7 yrs. Timing varies from person to person.
For education only. This is not dental advice; your dentist can tell you what is right for your own teeth.