How to diagnose periodontitis

A series of measurements are required to understand the extent and severity of the disease.

These measurements can include:

• Probing pocket depth (PPD)
• Gingival recession
• Furcation involvement – bone loss between the roots of multi-rooted teeth
• Tooth mobility
• Full mouth bleeding score/ Full mouth bleeding on probing (BoP)
• Full mouth plaque score

Once the clinical measurements are complete, radiographs may be required to assess the alveolar bone loss.

How is periodontitis diagnosed?

Using all of the above information, periodontitis will be classified using these key parameters:

Extent – How much of your mouth is affected?

• Generalised – more than 30% of teeth are affected
• Localised – less than 30% of teeth are affected
• Molar-incisor pattern – this mainly affects the first molars and incisors

Staging – The stage reflects how much bone has been lost due to periodontitis. It is assessed by looking at the worst-affected tooth on your radiograph.

• Stage I (early/ mild): less than 15% of bone loss
• Stage II (moderate): Bone loss within the coronal third (initial third) of the root
• Stage III (severe): Bone loss within the mid third of the root
• Stage IV (very severe): Bone loss extending to the apical third (final third) of the root

Grading – The grade gives an idea on the rate of progression of the disease process by comparing the amount of bone lost with your age:

• Grade A: Slow rate of progression
• Grade B: Moderate rate of progression
• Grade C: Rapid rate of progression

Current status – How are the gums right now?

• Currently stable: PPD ≤4mm (with no BoP at 4mm sites), BoP <10%
• Currently in remission: PPD ≤4mm (with no BoP at 4mm sites)
• Currently unstable: PPD ≥5mm or PPD 4mm with BoP

Risk factor assessment:

• Inform the patient of risk factors which are likely to be contributing to the periodontitis (e.g. smoking, sub-optimally controlled diabetes)

References

BSP flowchart implementing the 2018 classification. Available here (Accessed: 05 January 2025).