If you’ve had a dental exam recently, you may remember your dentist placing what feels like a mental object in your gums, and calling out a number that the hygienist places on a computer. It may go something like this:

Dentist: “2. 3. 5… 3. 3. 3…. 3. 4. 3…”

Hygienist: “What number was that again?”

Dentist: “That was number 18.”

Hygienist: “Got it.”

Dentist: “4. 4. 4… 3. 5. 4….”

No, your dentist isn’t reading you lottery numbers or horse race trifectas. What your dentist is doing is reading the depth of each pocket around your teeth.

Why Pocket Depth?

In between your teeth and gum are some very small pockets. These pockets start at about 1 to 2 millimeters. When bacteria (plaque) develop, it eats away at the inside of the pockets, including both bone and tissue, causing the pockets to get even deeper.

Deeper pockets not only mean that your gums and teeth have been damaged. It also means that there is more room for even more bacteria to grow. So dentists, like Dr. Chen, Dr. Skelton, and Dr. Torabian of Esthetic Reflections, measure each pocket from multiple angles.

The numbers that you’re hearing refer to the millimeter depth of the tooth. A total of 6 measurements are taken for each tooth – the outward facing side and the tongue facing side, measured 3 per side (hence the three numbers).

When the hygienist is keeping track of these numbers, they will occasionally ask the dentist which tooth they are on to make sure they’re entering it correctly. Teeth are also given their own numbers, from 1 to 32, where 1 to 16 refer to a specific tooth on the upper jaw and 17 to 32 refer to a specific tooth on the lower jaw.

If you’re curious what the pocket depth numbers mean:

  • Healthy Teeth/Gums – Healthy teeth have a pocket depth from 1 to 3.
  • Unhealthy Teeth/Gums – Unhealthy teeth and gums have pocket depths from 4 and up.

If your dentist finds that you have only a few 4s and 5s, they may recommend simply brushing and flossing more often, or they may recommend cleaning a bit more often to see if the pocket reduces naturally.

If you have too many 4s and 5s, or you have numbers of 6 or more, additional treatment is often necessary. Pocket depth of 7 or above usually means there are some serious gum disease issues that require a more aggressive treatment.

Every mouth is different, so these guidelines may not be relevant to your specific mouth. Nevertheless, at least you now know why your dentist is reading off those numbers. Hopefully, you’re hearing a lot of 1s, 2s, and 3s, but if you do need any additional treatment, Folsom dentists Dr. Chen, Dr. Skelton, and Dr. Torabian are here to help.