3. Naming the disease — stage, grade, extent, status

UK implementation in one sentence

Screen with BPE → if periodontitis is possible or obvious, collect CAL/bone loss, smoking, diabetes, age → write a diagnosis a colleague could reconstruct: extent, stage, grade, current status (and risk factors).

Health and gingivitis (intact periodontium)

Clinical gingival health: little or no bleeding (BSP/EFP use a low full-mouth bleeding threshold — typically under 10% of sites). Gingivitis: inflammation without attachment loss, often described as localised or generalised by bleeding extent. These people are not periodontitis patients.

When it is periodontitis

Interdental attachment loss at two or more non-adjacent teeth, or buccal/oral attachment loss of 3 mm or more with pocketing of 3 mm or more at two or more teeth, that you cannot blame on another cause (for example a cervical restoration, recession from toothbrushing only, or an extraction socket). Then they are a periodontitis patient for life.

Stage (severity and complexity)

Stage I to IV describes how much destruction has already happened (and complexity such as missing teeth from periodontitis, bite collapse, or deep infrabony problems). Bone loss as a percentage of root length is the usual UK practical measure. Stage does not improve after treatment; current inflammation is described separately. Stage IV is more than “a few deep pockets” — it is severe disease plus function/complexity. BSP has published additional S3-type work specifically on Stage IV rehabilitation; use that when the case is that complex.

Grade (rate / susceptibility)

Grade A, B or C reflects how fast bone has been lost for the person’s age (often estimated as percentage bone loss divided by age). Direct evidence of progression over time is better if you have old films. Smoking and diabetes can push grade up. If you truly cannot grade, current UK teaching is not to invent Grade A to look kind — use the default in the current BSP diagnostic flowchart (commonly Grade B unless evidence says otherwise).

Extent

Localised versus generalised is based on how many teeth are affected (the usual teaching cut is around 30%). Molar-incisor patterns still exist and should be named when that is the picture.

Current status

After you have a periodontitis diagnosis, say whether the person currently has gingival health on a reduced periodontium, gingival inflammation, or unstable periodontitis. That is what recall and Step 4 are for. Treatment success is not “the BPE became a 2”.