Tooth #9 – Upper left central incisor
1st tooth back from the middle, upper left.
- International
- 21
- Palmer
- 1
- Type
- Incisor
- Roots
- 1
- Canals
- usually 1
- Comes in
- 7–8 years
One of the two front teeth in the upper jaw, the one on the left.
- Next to it, across the middle: #8 upper right central incisor
- Behind: #10 upper left lateral incisor
- Bites against: #24 lower left central incisor
It replaces the upper left baby central incisor (F), which falls out at 6–7 years.
One root and one canal.
Upper central incisors: roots, canals and the studies behind the counts →
This tooth is #9 in the US and 21 in the international (FDI) system, where the 2 means the upper left quarter and the 1 is its place counting from the front.
There's no international tooth 9, because those numbers always have two digits.
And in the US, #21 is the lower left first premolar.
American Dental Association 2024; Harris 2005; American Dental Association 2012. Full titles are on the About page.