How Are Teeth Numbered in the Human Mouth?
Throughout the lifespan, an individual will have two sets of teeth: 20 primary (baby) teeth and then 32 permanent (adult) teeth. There are two numbering systems used to identify specific teeth within each of these sets.TypesThe American Dental Association uses two widely-accepted systems for numbering teeth: the Universal/National System which is used mostly in the U.S. and the International Standards Organization System common in most other countries.ExampleWhen using the Universal/National System to number teeth, it’s helpful to think of how the teeth are arranged when you look into a person’s wide open mouth.Permanent TeethAdult teeth are numbered from one to 32, with the number one tooth being the right back molar. The numerical sequence then goes around the person’s upper arch toward the front of the mouth, and then to the upper left back molar (#16). Counting starts again at the back molar on the left side of the lower jaw (#17) and ends at the right lower back molar (#32).Primar
