Dental charting is the process of mapping every tooth in a patient’s mouth, recording its condition, existing restorations, disease, and periodontal health on a standardized form. Whether you’re working on paper or in digital software, the fundamentals are the same: identify each tooth by number, note what you see on each surface, and measure the gums. Here’s how the entire process works, from tooth numbering to periodontal probing.
Learn the Tooth Numbering System
Before you chart anything, you need to know which tooth you’re talking about. In the United States, the standard is the Universal Numbering System adopted by the American Dental Association. For adults, every permanent tooth gets a number from 1 to 32. For children, primary (baby) teeth are lettered A through T.
The numbering starts at the upper right third molar (wisdom tooth), which is tooth #1. From there, you count across the entire upper arch to the left, ending at the upper left third molar, tooth #16. Then you drop down to the lower left third molar, tooth #17, and count across the bottom arch back to the right, finishing at the lower right third molar, tooth #32. Think of it as a big horseshoe: you trace the top from right to left, then the bottom from left to right.
Primary teeth follow the same path but use letters. The upper right second molar is A, you trace across the top to J (upper left second molar), drop to K (lower left second molar), and end at T (lower right second molar). Since children only have 20 primary teeth, you only need 20 letters.
A few landmarks worth memorizing: teeth #8 and #9 are the upper front teeth (central incisors). Teeth #6 and #11 are the upper canines. Teeth #14 and #19 are the first molars on the left side, while #3 and #30 are first molars on the right. Once you know these anchor points, the rest falls into place quickly.
Know the Five Tooth Surfaces
Every tooth has multiple surfaces, and charting requires you to specify exactly which surface has a filling, cavity, or other finding. Five abbreviations cover all of them:
- M (Mesial): The side of the tooth facing toward the midline of the mouth (toward the front).
- D (Distal): The side facing away from the midline (toward the back).
- B (Buccal): The side facing the cheek.
- L (Lingual): The side facing the tongue. On upper teeth, this is sometimes called the palatal surface.
- O (Occlusal): The chewing surface of premolars and molars. For front teeth, this surface is called the incisal edge, abbreviated I.
When a restoration or cavity spans multiple surfaces, you combine the letters. A filling on the mesial, occlusal, and distal surfaces of a molar would be charted as “MOD.” A cavity on the mesial and incisal surfaces of a front tooth is “MI.” These abbreviations are used universally in both paper charts and electronic dental records.
Chart Existing Conditions Tooth by Tooth
A complete dental chart captures everything already present in the mouth before any new treatment. You’ll work through each tooth systematically, typically starting at tooth #1 and ending at #32. For each tooth, you record:
- Missing teeth: Marked with an X drawn through the tooth on the chart.
- Existing restorations: Fillings are drawn on the specific surfaces involved and colored or labeled to indicate the material. Blue or a specific outline pattern typically indicates a tooth-colored (composite) restoration, while solid coloring or a different convention marks a metal (amalgam) filling.
- Crowns: Drawn as an outline circling the entire crown of the tooth.
- Bridges: The false tooth (pontic) is marked with an X and connected to the crowned anchor teeth on either side with a line.
- Decay: Active cavities are typically outlined in red on the affected surfaces, distinguishing them from existing restorations.
- Root canals: A vertical line drawn through the root of the tooth on the chart.
- Implants: Indicated with a specific symbol at the root area, often resembling a screw or post.
If you’re doing this on paper, you literally draw these symbols onto a printed diagram of 32 teeth. In digital charting software, you select the tooth, click the surfaces involved, and choose the condition from a menu. The software generates the visual representation for you. Either way, the goal is the same: anyone who looks at this chart should be able to see the full picture of the patient’s mouth at a glance.
Measure Periodontal Probing Depths
The second major component of dental charting is the periodontal assessment, which evaluates the health of the gums and bone supporting the teeth. The core measurement is probing depth: how deep the space (pocket) is between the gum and the tooth, measured in millimeters with a thin probe.
Six measurements are taken per tooth: three on the cheek side (buccal) and three on the tongue side (lingual). That means for a full mouth of 28 teeth (excluding wisdom teeth in many patients), you’re recording around 168 individual measurements. Each number is written in a row on the periodontal chart, aligned under the corresponding tooth.
Healthy pockets measure 1 to 3 mm. Once a pocket reaches 4 mm or deeper, it’s generally considered a sign of periodontal disease. Depths of 5 mm or more indicate more significant bone loss and a higher risk of progressive disease. These numbers are the backbone of a periodontal diagnosis, so accuracy matters. The probe should be walked gently along the base of the pocket, not jabbed, and readings should be taken at six distinct points around each tooth.
Record Bleeding, Recession, and Attachment Loss
While probing, you also note whether each site bleeds. Bleeding on probing is a sign of active inflammation in the gum tissue. It’s typically recorded as a simple yes/no at each probing site, marked with a red dot or a filled circle on the chart. To calculate a patient’s overall bleeding score, divide the number of sites that bled by the total number of sites probed, then multiply by 100 to get a percentage. A score above 10% generally signals a problem.
Recession is the next measurement. This is how far the gum has pulled away from its normal position at the crown of the tooth, exposing the root. You measure in millimeters from where the gum should be (the junction between the crown and root) to where it actually sits. If the gum covers that junction, you record a negative number.
Together, probing depth and recession give you the clinical attachment level, which represents the true amount of support the tooth has lost. The formula is straightforward: add the probing depth to the recession measurement. For example, if a site has a 5 mm pocket and 2 mm of recession, the clinical attachment level is 7 mm. This number is more diagnostically meaningful than probing depth alone because it accounts for gum position. A 3 mm pocket with 4 mm of recession is actually worse than a 5 mm pocket with no recession, even though the pocket is shallower.
Assess Tooth Mobility
Each tooth is tested for looseness, which indicates bone loss or trauma. The standard scale, known as the Miller classification, uses four grades:
- Class 0: No detectable movement.
- Class 1: Slight, barely noticeable movement.
- Class 2: The crown moves up to 1 mm in any direction.
- Class 3: Movement greater than 1 mm, or the tooth can be pushed down into its socket or rotated.
To test mobility, place the handles of two instruments on opposite sides of the tooth and apply gentle pressure back and forth. The mobility grade for each tooth is recorded on the chart, usually in a dedicated row above or below the probing depths.
Check Furcation Involvement
Molars have two or three roots that branch apart at an area called the furcation. When bone loss reaches this branching point, it’s called furcation involvement, and it gets its own classification on the chart. The Glickman system is the most widely used:
- Grade I: A pocket extends into the furcation area, but the bone between the roots is still intact.
- Grade II: Bone loss has reached between the roots but doesn’t go all the way through to the other side.
- Grade III: Bone loss extends completely through the furcation from one side to the other.
- Grade IV: A through-and-through lesion with gum recession, making the furcation visible to the naked eye.
Furcation involvement is tested using a curved probe (called a Nabers probe) that’s specifically shaped to reach into the space between roots. The grade is recorded on the chart next to the affected tooth, often with a triangle symbol whose fill level corresponds to the grade.
Putting the Full Chart Together
A complete dental chart combines all of these elements into one document. The typical layout has a visual diagram of all 32 teeth in the center, with rows of numbers above and below for periodontal data. Here’s a practical sequence for completing one efficiently:
Start with the visual exam. Work through teeth #1 to #32, marking missing teeth, existing restorations, crowns, bridges, implants, and any visible decay on the tooth diagram. Call out each finding so the person recording (if you have an assistant) can mark it in real time. Use consistent language: “Tooth number 19, MOD amalgam” or “Tooth number 9, porcelain crown.”
Next, do the periodontal probing. Start on the buccal (cheek side) of the upper right, probe all the way across the upper arch, then switch to the lingual (tongue side) and work back. Drop to the lower arch and repeat. Call out numbers in groups of three for each tooth: “3, 2, 3” means the three sites on that tooth measured 3 mm, 2 mm, and 3 mm. Note bleeding as you go.
Then record recession measurements, mobility scores, and furcation grades for any teeth that need them. Finally, note any other findings: teeth that are rotated, tilted, or partially erupted, as well as any abnormalities in the soft tissue like lesions or swelling.
The whole process takes about 15 to 20 minutes for an experienced team. Speed comes from consistency: always working in the same order, using the same callout language, and knowing the numbering system cold. If you’re learning, practice by charting classmates or family members until the numbering and surface abbreviations become second nature.