Dental Terminology and Tooth Numbering

May 26, 2023

By Dr. Fass

When your dentist and the dental team are discussing your teeth, you may hear them refer to the teeth by number instead of name. The numbering systems came about to allow much quicker identification of teeth in a universal manner. This was made more necessary when computers became standard in the dental office and a simple numbering system was needed for easy data entry.

In the standard system used in the United States, the teeth are numbered starting with the upper right 3rd molar, or wisdom tooth being #1. The numbers progress around the upper arch to the upper left wisdom tooth, #16. The lower left 3rd molar is #17 and the numbers go around the lower arch to the lower right 3rd molar, #32. The numbers are absolute, that is, when a tooth is lost, the numbers of the other teeth don’t change.

Other numbering systems are used by some specialists. For example, orthodontists generally deal with teeth in a symmetrical way and may use a system that starts with tooth #1 in the center of the mouth and counts back to #8 for the 3rd molars. They identify the quadrant by the letters UR (Upper right), UL, LL, and LR. They will often refer to the permanent first molars as the “6’s”, being the sixth teeth from the front in all four quadrants. Still other systems number the quadrants 1, 2, 3, or 4. In this system, the upper right first molar is #16, the upper left first molar is #26 and so on.

Additionally, each tooth is deemed to have 5 surfaces, a front, back, 2 sides and a top like a box. Since the mouth curves, using terms like front and back can be confusing when we get to the corners at the canine teeth. We instead name these surfaces for the way they face in the arch. Mesial (toward the midline), distal (away from the midline), facial (towards the face), lingual (towards the tongue), and occlusal (the biting surface). We use the first letter of these designations to identify the surfaces involved in decay, trauma or fillings.

When you hear your dental team using numbers and letters during an examination, they are using this shorthand notation to map your current condition, or your dental needs. Some patients feel that we’re trying to hide information from them, but it’s simply a way for us to record the needed information for an individual patient quickly and accurately.

Your dental team should always take the time to explain their findings in plain language that you can understand. That way you can make the decisions on treatment that you feel are best for you.

The real goal is to keep all your teeth healthy, from #1 to #32.

This article was published on 05-26-2023 in The Altamont Enterprise.