Tooth number 31 is the lower right second molar, a permanent (adult) tooth. In the FDI (ISO 3950) system it is 47, and in Palmer notation it is 7┐.
Tooth #31 at a glance
| Universal (US) | 31 |
| FDI / ISO 3950 | 47 |
| Palmer | 7┐ |
| Name | Lower right second molar |
| Type | Second molar (adult tooth) |
| Jaw | Lower (mandible) |
| Side | Patient’s right |
| Comes in | 11-13 yrs |
| Roots | 2 |
| Root canals (usual) | usually 3 |
| Chewing surface | 4 cusps |
Where it is and what it does
It sits in the lower jaw on the patient’s right side, seventh from the midline. Molars are the main grinding teeth. Their broad, cusped chewing surfaces do the heavy work of breaking food down.
Neighbouring and related teeth
- In front of it (toward the midline): Tooth number 30, the lower right first molar
- Behind it: Tooth number 32, the lower right third molar
- Same tooth on the other side: Tooth number 18
- The matching tooth in the upper jaw: Tooth number 2
- It does not replace a baby tooth. Adult molars grow in behind the baby teeth.
Common dental work on this tooth
Molars get more cavities than any other teeth because of the deep grooves on their chewing surfaces. Common treatments include sealants, fillings, crowns and root canals.
Questions
What tooth is number 31?
Tooth number 31 is the lower right second molar. 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 31 in the FDI and Palmer systems?
In FDI it is 47, said digit by digit (“four-seven”). The first digit is the quadrant and the second is the position from the midline. In Palmer notation it is 7┐.
When does tooth 31 come in?
Usually at about 11-13 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.