Periodontal charting guide

A periodontal chart records the state of the gums and bone around every tooth: pocket depths, the position of the gingival margin, bleeding, plaque, furcation and mobility. This guide explains what each field means, which figures summarise a chart, and how Smile Perio helps you chart quickly, compare visits and share.

Sites and layouts

Each tooth is probed at several points (sites). A full chart measures six sites per tooth: distal, mid and mesial on the buccal side, and the same three on the lingual or palatal side. A partial chart measures two sites per tooth, a basic chart one.

Smile Perio offers four layouts: full with six sites, full with a single plaque score per tooth, partial with two sites, and basic with one site. The layout is picked before the first value and can be set as the default for new charts in Settings.

The fields

Probing depth (PD): The distance in millimetres from the gingival margin to the bottom of the pocket, measured with a periodontal probe. 1 to 3 mm is healthy, 4 mm borderline, 5 mm and above is a deep pocket. It is the only field that is always collected.
Gingival margin (GM): The position of the gum margin relative to the cemento-enamel junction (CEJ). Recession is a positive number. A negative value means the gum covers the CEJ, as with swelling.
Clinical attachment level (CAL): Computed automatically: probing depth plus recession. The most reliable measure of cumulative periodontal destruction, and the basis of the 2018 classification.
Bleeding on probing (BOP): Whether the site bled after probing. A sign of active inflammation. The percentage of bleeding sites is the first figure to follow between visits.
Plaque: A score of 0 to 3 per site, or one value per tooth. 0 is no plaque, 3 heavy plaque. Also summarised as the percentage of sites with plaque.
Furcation: Involvement of the root division area on molars and upper first premolars. Grade I to III by how far the probe enters.
Mobility: Grade 0 to 3 per tooth: 0 firm, 1 slight movement, 2 up to a millimetre, 3 vertical movement.
Implant: Marks the tooth as an implant. Implants have no furcation and CAL reads differently.

Summary figures

BOP %: Bleeding sites as a share of all measured sites. Below 10% is considered stable; above 25% points to active inflammation that needs treatment.
Sites ≥5 mm: The number of sites with a pocket of 5 mm or more, and the number of teeth they belong to. These are the sites that need treatment.
Mean PD and mean CAL: Averages over all measured sites. Useful for comparing visits, less so for a single tooth.
PESA (Periodontal Epithelial Surface Area): An estimate of the pocket epithelium area in square millimetres: pocket depth times site width, summed. Deeper pockets mean a larger inflamed surface.
PISA (Periodontal Inflamed Surface Area): The same calculation over bleeding sites only. It estimates the area of active inflammation in the mouth, and studies link it to systemic conditions such as diabetes.

Periodontitis classification, AAP/EFP 2018

The 2018 classification describes every patient on two axes: Stage (severity and complexity) and Grade (rate of progression and risk factors).

Stage I: CAL of 1 to 2 mm, bone loss in the coronal third, no tooth loss.
Stage II: CAL of 3 to 4 mm, bone loss of 15 to 33 percent, no tooth loss.
Stage III: CAL of 5 mm or more, bone loss beyond the coronal third, up to four teeth lost, pockets of 6 mm or more or furcation II to III.
Stage IV: As Stage III, plus five or more teeth lost, masticatory dysfunction, mobility 2 or more, or fewer than twenty teeth.
Grade A, B, C: Rate of progression: slow, moderate or rapid. Set from bone loss over time, or from the ratio of percentage bone loss to age. Smoking and uncontrolled diabetes raise the grade.
Extent: Localized (under 30% of teeth), generalized (30% or more) or molar-incisor pattern.

Smile Perio suggests a Stage from the maximum CAL, the maximum pocket depth and the number of teeth with furcation II or more. The suggestion is a floor only: the chart cannot see radiographic bone loss, the cause of tooth loss or history, so the clinician confirms or raises it.
Reference: Tonetti MS, Greenwell H, Kornman KS. Staging and grading of periodontitis. J Periodontol. 2018;89(Suppl 1):S159–S172.

Fast entry in Smile Perio

Every digit lands and moves the cursor to the next site at once. For 10 and above press Shift with the digit. On a phone an on-screen keypad has a 10+ key.
B marks bleeding and P adds plaque at the site just entered, like dictation: "3, bleeding". After a navigation key they apply to the current site.
Enter jumps to the next tooth, Backspace goes one site back, G and D switch between gingival margin and probing depth at the same site, M goes to mobility and F cycles furcation. Missing teeth are skipped automatically.
The entry order is yours to pick: by side (all buccal, then lingual), by tooth (GM then PD, tooth after tooth) or by arch.
Review mode shows PD and BOP only, for maintenance visits.

Comparing visits, sharing and PDF

Charts of the same patient (same alias) can be compared: every site that got worse or better is coloured, with change summaries for BOP and pocket depth.
Sharing by link: the whole chart is compressed into the link itself and never stored on a server. A QR code opens the chart on a phone.
A one-page A4 PDF: tables, arch drawings with pocket depths, summary and legend. Created on the device, ready for the patient file or a referral.

Privacy

Smile Perio runs in the browser only. Charts are stored on your device (IndexedDB) and never sent to a server. No account, no sign-up, no tracking. Use an alias instead of a full name, and export a JSON backup now and then.

Frequently asked questions

What is the difference between probing depth and CAL?

Probing depth is measured from the gingival margin, which can move. CAL is measured from the CEJ, a fixed point, so it reflects cumulative destruction. With recession CAL exceeds PD; with swollen gums CAL is below PD.

What is a normal BOP?

Under 10% of sites is considered stable. 10 to 25% needs monitoring. Above 25% points to active inflammation.

What is PISA and why does it matter?

PISA estimates the area of active inflammation in square millimetres from pocket depths at bleeding sites. It turns the whole chart into one number you can follow, and studies link it to systemic conditions.

Is Smile Perio free?

Yes. No account, no payment. It is built by SmileCloud, dental practice management software, and works alongside any practice system.

Where are the charts stored?

In the browser of the device you worked on. They never go to a server. Export JSON for a backup, or share a single chart by link.

Ready? A new chart opens right away, no sign-up. Open a new chart

Updated October 2026 · SmileCloud