What do the tooth numbers mean?

By: Dr. Taha Jomha, Aug 03, 2012

Why do I always hear my dentist referring to different numbers?

The mouth is divided into 4 sections that we call quadrants.

Have u ever wanted to know what the dentist is talking about when he is reading out a bunch of random numbers? This post will discuss the tooth numbering system that dentists use in Canada. I will also discuss briefly the surfaces of teeth.

The mouth is divided into 4 sections that we call quadrants. Quadrant 1 is the upper right, 2 is the upper left, 3 is the lower left, and 4 is the lower right. If you were facing a person then quadrant 1 is YOUR upper left and then go clockwise and you are going 2, 3, 4.

Within each quadrant of your mouth there are 8 teeth. Teeth 1 and 2 are the incisors. 3 is the canine (cuspid). 4 and 5 are bicuspids.  6, 7, and 8 are molars. The 6 is your 6 year molar, the 7 your 12 year molar, and the 8 is your wisdom tooth.

Identifying a tooth is easy.  All tooth numbers are a combination of the quadrant and then the tooth number. For example, tooth number 14 would be the upper right bicuspid. Tooth 21 is the first incisor on the top left. How about your bottom right wisdom tooth? This would be tooth number 48.

There are 4 additional quadrants used in dentistry. These are used to identify primary or baby teeth. Quadrant 5 is the baby tooth version of quadrant 1. Quadrant 6 is the baby tooth version of quadrant 2 and so on and so forth. For example if you were referring to tooth 51, this is the baby first incisor. Including wisdom teeth there are 32 adult teeth and 20 baby teeth.

In addition to tooth numbers dentists also describe a tooth or filling by its surfaces.  A tooth has the following services:

M – mesial, the front of the tooth
D – distal, the back of the tooth
O – occlusal, the top of the tooth
B – buccal, the outside surface of the tooth (facing cheek)
L – lingual, the inside surface of the tooth (facing tongue)

For example if your dentist says you need a filling 16MOD. This means that the filling is on the top right first molar, and the mesial, occlusal, and distal surfaces are involved.

Dr. Taha H Jomha (general Edmonton dentist) currently practices in Edmonton, Alberta. He entered dental school with distinction after completing 2 years of general science at the University of Alberta. He graduated from dental school in 2007. After associating for 18 months he decided to open his own dental clinic, Summerlea Dental. The vision of the clinic was to provide safe and comfortable dental care keeping up with the current standards. His office focuses primary on Family Dental Care. Dr. Jomha offers a range of dental services including fillings, root canals, dental implants (surgery and crown), wisdom teeth removal, whitening and more. Dr. Jomha continues to participate in continuing education courses to keep up with the quickly changing dental technology. http://www.summerleadental.com/