Understanding Tooth Terminology

One thing about a routine dental visit that can make some people uncomfortable is a lack of understanding regarding the terminology used to describe various dental conditions. It’s like two people are talking about you in a different language. I’m sure you are familiar with what usually happens: In most dental offices, after the hygienist cleans your teeth, the dentist comes in for the examination. Then, out of nowhere, he or she starts rattling off alpha-numeric jargon like, “3 MOD, 5 DO, 13 MFD,” and so on. You might be thinking that your dentist is looking at a bowl of alphabet soup instead of your mouth, but he or she is actually using a form of dental shorthand. The numbers represent specific teeth, and the letters, discrete areas of those teeth.

The numbering system begins with number one and ends with number 32 for adult teeth (children’s teeth use a letter system, the 20 teeth beginning with “A” and ending with “T”). Tooth number one is the upper-right third molar or wisdom tooth, the farthest tooth back on the right side of the mouth. Tooth number 16 is the upper-left third molar, also a wisdom tooth. Tooth number 17 is the lower-left third molar, and tooth number 32 is the lower-right third molar; both are lower wisdom teeth. Teeth numbers 8 and 9 are the upper-front teeth, or right and left central incisors, and teeth 24 and 25 are the lower front teeth, or lower left and right central incisors.

The letter part of the code refers to different areas or surfaces of the tooth. An "M" stands for mesial; "D" for distal -- which are the front or back part of the tooth, respectively. An "O" means occlusal, which is the top or biting surface of a back tooth; and "I" stands for incisal, which is the biting edge of the front teeth. "B" stands for buccal, which is the surface of the tooth towards the cheek; and an "L" means lingual; which is the surface of the tooth towards the tongue.

So if your dentist says number 3 MOD, you'll know that you have a cavity on your upper right first molar, involving the front, top and back parts of the tooth. With a little practice, you’ll know much more about what your dentist is saying “behind your back!”