Baby tooth L is the lower left first molar in the baby (primary) teeth. In the FDI (ISO 3950) system it is 74, and in Palmer notation it is ┌D. It usually comes in at 14-18 mos and falls out at 9-11 yrs.
Tooth L at a glance
| Universal (US) | L |
| FDI / ISO 3950 | 74 |
| Palmer | ┌D |
| Name | Lower left first molar |
| Type | First molar (baby tooth) |
| Jaw | Lower (mandible) |
| Side | Patient’s left |
| Comes in | 14-18 mos |
| Falls out | 9-11 yrs |
| Roots | 2, widely spread |
| 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 left side, fourth from the midline, just behind the canine. Baby molars do most of a young child’s chewing. They also hold the space for the adult premolars that will grow in underneath them, so losing one early can let neighbouring teeth drift.
Neighbouring and related teeth
- In front of it (toward the midline): Baby tooth M, the lower left canine
- Behind it: Baby tooth K, the lower left second molar
- Same tooth on the other side: Baby tooth S
- The matching tooth in the upper jaw: Baby tooth I
- Replaced by: Tooth number 21, the lower left first premolar (adult premolars replace baby molars)
Common dental work on this tooth
Baby molars can get cavities between them and in the grooves on top, so dentists often check them closely. Treatments include fillings, sealants and small crowns. If a baby molar is lost early, a space maintainer may be used to keep room for the adult tooth.
Questions
What tooth is letter L?
Baby tooth L is the lower left first molar (a baby tooth). Letters A to T are used for baby teeth in the Universal system used in the United States.
What is baby tooth L in the FDI and Palmer systems?
In FDI it is 74, said digit by digit (“seven-four”). The first digit is the quadrant and the second is the position from the midline. In Palmer notation it is ┌D.
When does baby tooth L fall out?
Usually at about 9-11 yrs, when the adult lower left first premolar pushes it out from underneath. It first comes in at about 14-18 mos.
For education only. This is not dental advice; your dentist can tell you what is right for your own teeth.