Lower lateral incisors – #23 and #26
The narrower front teeth on either side of the lower central incisors.
Roots
One root (99.8% of more than 1,100 teeth in pooled Saudi studies).
Canals
Usually one. A second canal turns up in about 26% of these teeth worldwide, and in 43% in pooled Saudi studies.
These are typical counts from scan studies. Teeth vary, and only an X-ray or scan shows what a particular tooth has.
When they come in
Usually at 7–8 years old, according to the ADA's eruption chart.
They replace the lower baby lateral incisors, which fall out at 7–8 years.
They bite against the upper lateral incisors.
Sources
Mashyakhy et al. 2022; Martins et al. 2023; Usha et al. 2021; American Dental Association 2012; Harris 2005. Full titles are on the About page.