Tooth #18 – Lower left second molar
7th tooth back from the middle, lower left.
- International
- 37
- Palmer
- 7
- Type
- Molar
- Roots
- 2
- Canals
- usually 3
- Comes in
- 11–13 years
The big back tooth between the first molar and the wisdom tooth on the lower left.
- In front: #19 lower left first molar
- Behind: #17 lower left wisdom tooth
- Same tooth on the other side: #31 lower right second molar
- Bites against: #15 upper left second molar
None. Adult molars come in behind the baby teeth instead of replacing one.
Usually two roots (1–3) and usually three canals (2–4).
Lower second molars: roots, canals and the studies behind the counts →
This tooth is #18 in the US and 37 in the international (FDI) system, where the 3 means the lower left quarter and the 7 is its place counting from the front.
In the international system, 18 is the upper right wisdom tooth (#1).
American Dental Association 2024; Harris 2005; American Dental Association 2012. Full titles are on the About page.