Editorial status: Evidence-informed draft for clinician review. A periodontal chart supports diagnosis only when interpreted with history, examination and radiographs.

A chart is a map of measured sites

A periodontal chart records conditions around each tooth, commonly at six sites. It helps locate inflammation, attachment loss, recession, furcation involvement and mobility and provides a baseline for comparison. One number cannot diagnose periodontitis, and a printed chart without the examination date, examiner and clinical context can be misleading.

Tooth numbering and site orientation

First identify the numbering system and whether the chart shows upper or lower, right or left and cheek, tongue or palate surfaces. International and US tooth numbers differ. Each tooth may have mesial, middle and distal measurements on facial and lingual surfaces. Confirm the missing, implant and pontic symbols before reading patterns.

Probing depth

Probing depth is the distance from the gingival margin to the base of the probeable sulcus or pocket. It reflects current pocket anatomy, not the lifetime amount of support lost. Swollen gums can produce a deeper reading without equivalent attachment loss, while recession can expose substantial loss with a shallow current pocket.

Clinical attachment level

Clinical attachment level estimates the position of the attachment relative to a fixed landmark, usually the cemento-enamel junction. It combines probing depth with recession or gingival enlargement. Attachment loss is central to periodontitis case definition, but restorations, abrasion and difficulty finding the landmark can affect measurement.

Gingival recession

Recession records the gingival margin apical to the cemento-enamel junction. It can relate to periodontitis, thin tissue, brushing trauma, tooth position, surgery or other factors. Recession influences sensitivity, root caries, appearance and cleaning. It should not be added to pocket depth blindly when the reference landmark is uncertain.

Gingival enlargement

When the margin lies coronally to the cemento-enamel junction, tissue enlargement can create a deep pseudopocket without attachment loss. Medicines, plaque, inflammation and systemic conditions may contribute. Treatment and prognosis differ from a true pocket with supporting-tissue destruction.

Bleeding on probing

Bleeding after gentle probing indicates inflamed tissue but is influenced by probing force and timing. A single bleeding site does not define whole-mouth disease. Patterns and percentages are more informative, and persistent bleeding at deep sites is clinically important. Absence of bleeding can support stability but does not replace full assessment.

Suppuration

Suppuration means purulent exudate from a site and suggests active inflammation or infection. It requires clinical evaluation but is not present in every diseased pocket. Record the exact tooth and surface. Swelling, fever, spreading infection or systemic illness changes urgency.

Plaque and calculus

Plaque scores indicate biofilm control at the examination, while calculus records mineralised deposits. They help identify modifiable risk and cleaning barriers. A low plaque score on one day does not erase historical disease, and a high score should prompt coaching and design review rather than blame alone.

Furcation involvement

Furcation is bone and attachment loss between the roots of a multi-rooted tooth. Its degree, entrance anatomy, root separation and cleaning access affect prognosis. A two-dimensional radiograph can underestimate or obscure furcation involvement, so clinical probing and imaging are interpreted together.

Mobility

Mobility can arise from reduced support, inflammation, trauma from occlusion, root fracture or other causes. Grading systems vary. Mobility may decrease after inflammation and bite factors are controlled, so it should not be used alone as an automatic extraction criterion.

Mucogingival findings

The chart may include keratinised tissue, frenum pull, tissue phenotype and recession type. These findings affect comfort, hygiene and surgical planning but do not independently diagnose periodontitis. Record patient symptoms and whether a restoration or implant contour limits cleaning.

Implants should be identified separately

Implant probing is interpreted against implant-specific baselines; tooth thresholds cannot simply be copied. Mark implants, abutments and prosthesis design. Peri-implant health can exist with reduced support, and no universal probing depth alone defines health or disease.

Why six sites matter

Periodontal destruction can be localised. Measuring only one or two sites can miss a deep interproximal defect. Full-mouth six-site charting supports diagnosis and monitoring, although screening tools may be used initially. A treatment plan involving multiple crowns or implants deserves a complete periodontal foundation assessment.

Probe force and angulation

Readings vary with force, tissue inflammation, probe diameter, angulation, access and examiner calibration. The probe should follow the root contour, and interproximal sites require appropriate angulation. A one-millimetre change at one site may reflect measurement variation; repeated patterns and accompanying inflammation matter.

Manual and electronic probes

Manual probes remain the clinical standard. Pressure-sensitive or electronic systems may improve aspects of reproducibility but systematic review evidence does not show clear overall superiority. Consistent technique and trained examiners are more important than a technology label.

Chart date and examiner

Every chart should show date, examiner and relevant treatment stage. Measurements taken before debridement may differ from those after inflammation resolves. Comparing charts from different clinics requires awareness of technique and reference points. An undated screenshot is weak evidence of progression.

Radiographs add different information

Radiographs show hard-tissue levels and patterns but not current bleeding, pocket depth or soft-tissue margin. Projection, angulation and image quality affect comparison. A radiographic defect does not reveal whether disease is currently active, and a normal two-dimensional image can miss early or facial-lingual changes.

Bone loss pattern

Horizontal loss is broadly parallel to a line between adjacent teeth; vertical or angular defects have an oblique pattern. Pattern, remaining support, root anatomy and furcations influence complexity and surgical options. Percentage estimates require a consistent reference and should be interpreted with age and history.

Staging periodontitis

Staging describes severity and treatment complexity, considering attachment or bone loss, tooth loss due to periodontitis and complexity factors. It is not a simple label derived from the deepest pocket alone. The clinician should identify what evidence supports the selected stage.

Grading periodontitis

Grading estimates progression and risk using direct evidence over time or indirect evidence such as bone loss relative to age, modified by factors including smoking and diabetes. A grade is a reasoned risk estimate, not a certainty about future loss. It should be updated when new information becomes available.

Extent and distribution

Periodontitis may be localised, generalised or show a molar-incisor pattern. Extent depends on the proportion and distribution of affected teeth. A whole-mouth label should not hide that a few sites may drive treatment complexity while other teeth are stable.

Gingivitis versus periodontitis

Gingivitis involves inflammation without attachment loss caused by periodontitis. Periodontitis involves loss of supporting tissues. A patient with treated periodontitis can have shallow pockets and still retain the historical diagnosis because recurrence risk and maintenance needs remain.

Current stability

After treatment, assess bleeding, residual pockets, suppuration and progression. Proposed stability endpoints are useful but can be difficult to achieve completely; evidence shows many treated patients preserve most teeth despite not meeting strict whole-mouth endpoints. The plan should focus on residual risk sites and maintenance.

What improvement looks like

Reduced bleeding, shallower inflamed pockets, stable attachment, improved plaque control and absence of progression can indicate response. Some recession may increase as swelling resolves, making a pocket shallower without regaining attachment. Explain this before treatment so the patient understands longer-looking teeth or sensitivity.

What progression looks like

Concern rises with reproducible attachment loss, increasing pocket depth with inflammation, new suppuration, worsening mobility or radiographic bone loss beyond expected variation. A single differing number should be rechecked. The clinician should document whether change is site-specific or generalised and identify modifiable causes.

Periodontal chart before restorative care

Definitive crowns, veneers and bridges should not conceal active periodontal disease or create inaccessible margins. The chart helps plan margin position, crown lengthening, provisional tissue response and supporting-tooth prognosis. Cosmetic deadlines should not replace disease control.

Periodontal chart before implants

History of periodontitis and current inflammation affect implant risk and maintenance. Treat active disease, assess hygiene and record baseline tooth status before implant placement. Extracting periodontally compromised teeth does not remove the patient’s susceptibility or maintenance need.

A practical sequence for reading the chart

Begin with completeness rather than the largest red number. Confirm the date, tooth map, implant symbols and six-site coverage. Next review bleeding and suppuration to locate current inflammation. Then compare probing depth with recession or enlargement so that pocket anatomy is not confused with attachment loss. Add mobility and furcation findings, then place the pattern beside radiographs and previous charts. Only after this should the diagnosis, stage, grade and tooth-level prognosis be evaluated. This sequence reduces the risk that a dramatic isolated reading dominates the whole interpretation.

Worked example: a deep site with no recession

Imagine a molar site recorded at seven millimetres with bleeding, no visible recession and an angular radiographic defect. The finding deserves attention, but the chart alone cannot show whether the probe reached the same point previously, whether inflammation altered penetration or whether endodontic or fracture pathology contributes. Rechecking technique, reviewing adjacent sites and vitality, and comparing dated images can change the differential diagnosis. The treatment record should state the working diagnosis and the measurement used as the next baseline.

Worked example: a shallow site with major recession

A tooth may have a three-millimetre probing depth and five millimetres of recession. The current pocket is shallow, yet the attachment position may reflect substantial historical loss. The patient may face sensitivity, root caries, aesthetic concern and cleaning difficulty even without an actively deep pocket. Calling the tooth healthy from probing depth alone would miss these problems. Stability, phenotype, brushing method, restorative margins and progression over time determine whether monitoring, preventive care or mucogingival treatment is appropriate.

Whole-mouth percentages and local risk

Bleeding and plaque percentages summarise the mouth but can hide a high-risk local site. Conversely, a few bleeding points may produce a concerning percentage when few teeth remain. Read the numerator and denominator, distribution and site depth. A low whole-mouth bleeding score is encouraging, yet persistent bleeding around a deep furcation or implant remains important. Treatment goals should therefore include both global control and named sites that require closer review.

When two charts disagree

Differences can reflect real biological change, inflammation resolution, different probe force, charting software, examiner technique or rounding. Confirm that tooth and surface labels match and that recession was entered with the same sign convention. Reprobe a suspicious site and compare several neighbouring readings. Progression is more credible when attachment change is reproducible and supported by inflammation, radiographic change or repeated measurements. The uncertainty should be documented instead of converting every discrepancy into a claim of rapid disease.

Re-evaluation after non-surgical treatment

A post-treatment chart is not merely an administrative repeat. It shows how tissues responded after debridement and improved home care, identifies residual pockets and supports the next decision. Reduced swelling may cause more visible recession while probing depths fall. Residual deep bleeding sites may need additional instrumentation, access surgery, regenerative assessment or a revised diagnosis. The interval must allow healing and should be recorded so later clinicians know which phase the values represent.

Supportive periodontal care

Maintenance intervals should reflect diagnosis, residual pockets, bleeding, smoking, diabetes control, previous progression, implant status and the patient’s ability to clean. A generic six-month recall may be too infrequent for one patient and unnecessarily intensive for another. At maintenance, targeted probing may be combined with periodic comprehensive charting, but the clinic should define when a complete comparison will occur and what change triggers escalation.

Data portability and second opinions

A useful transferable record contains the raw site-level values, not only colour-coded graphics. Request a machine-readable export or clear PDF, dated radiographs, diagnosis, risk factors, tooth prognosis and completed treatment. For a second opinion, the receiving clinician may repeat measurements rather than accepting exact equivalence. That is not necessarily a contradiction; it creates an independently documented baseline and reveals whether the proposed plan depends on a reproducible finding.

Red flags that require prompt assessment

Acute swelling, spreading facial infection, fever, difficulty swallowing or breathing, rapidly increasing mobility, severe pain or purulent drainage requires timely professional assessment. A chart is not an emergency triage tool. Patients with immune suppression, poorly controlled systemic disease or recent major medical treatment may need closer coordination. Online interpretation must never delay urgent evaluation when systemic or airway symptoms are present.

Medical and behavioural modifiers

Smoking, glycaemic control, medicines, dry mouth, immune status and home-care ability influence risk and treatment. Record actual exposure and control rather than a yes-or-no box. The chart describes tissues; the risk assessment explains why similar charts may have different prognoses.

Questions to ask about your chart

Do I have attachment loss, inflammation or both?
Which sites bleed, suppurate or have furcation involvement?
What is my stage, grade and extent, and why?
Which teeth have uncertain prognosis?
What measurements will show response?
How often will a full chart be repeated?

Records to request

Ask for the dated six-site chart, recession or attachment values, bleeding and plaque scores, mobility and furcation entries, diagnosis, staging and grading rationale, radiographs and treatment notes. A machine-generated graphic without raw numbers limits continuity.

Common interpretation errors

Calling every four-millimetre site disease.
Equating pocket depth with total attachment loss.
Diagnosing from radiographs alone.
Comparing undated charts from different methods as exact.
Using mobility alone to justify extraction.
Ignoring recession and root caries risk after treatment.

Evidence summary

A periodontal chart is a longitudinal clinical dataset. Probing depth, attachment level, recession, bleeding, furcation and mobility answer different questions and contain measurement uncertainty. Diagnosis requires classification, radiographic context and risk modifiers; monitoring requires reproducible baselines and repeated site-level comparison.

Sources

Prepared as general educational information. A periodontal diagnosis requires examination by a qualified dental professional.

How to Read a Periodontal Chart