September 12, 2022
by Gabriele Maycher, CEO, GEM Dental Experts Inc. BSc, PID, dip DH, RDH
- Q: Has the definition of “localized” and “generalized” changed in reference to describing the extent of periodontal disease? There seems to be a lot of debate among the new grads and seasoned hygienists in our office.
A: The new 2018 American Academy of Periodontology (AAP) Classification changed the definition of these terms when describing extent of periodontal disease – and it’s an important distinction. They no longer refer to the number of sites but rather the number of teeth involved (as a percentage of teeth present).1 “Localized” means that fewer than 30% of teeth in the mouth are periodontally involved. The term “generalized” is used when 30% or more teeth in the mouth are periodontally involved.
However, when using the terms localized and generalized in describing deposit and gingival findings, we still use sites, not teeth, to describe the extent.
Also, it should be noted that with the new periodontitis staging and grading classification, we no longer describe the extent of the diagnosis as, “Localized Stage I with Generalized Stage II Periodontitis in posterior areas, Grade B.” This is categorically incorrect! It is localized or generalized, not both. So, the proper way to describe your periodontal condition or diagnosis in this case is, “Generalized Periodontitis, Stage II, Grade B,” since 30% or more teeth have been affected by periodontitis, and the stage descriptor assigned is based on the worst affected tooth in the dentition (attachment loss attributable to biofilm destruction related to periodontitis, not acquired and developmental conditions like open contacts, malocclusion, iatrogenic restoration, etc.).1 Stage II, for example, is defined as 3 – 4mm clinical attachment loss (CAL) or 15% – 33% radiographic bone loss (RBL).
In the 1999 AAP Periodontal Classification, molar incisor pattern was used as a primary descriptor for aggressive periodontitis, so the 2018 AAP Periodontal Classification included the molar/incisor pattern to the extent and distribution category. See Table 1: Periodontitis: Staging. The rationale for keeping this information in the classification systems comes from the fact that specific patterns of periodontitis (i.e., the molar-incisor pattern of younger patients) provides indirect information about the specific host-biofilm interactions.1
Table 1 – Periodontitis: Staging
If a distinct pattern of bone loss is confined to the molar and or anterior areas, then the proper way to describe the potential condition is Molar/Incisor Pattern Periodontitis, Stage II, Grade C.
Q: During a patient’s five-year follow-up periodontal maintenance appointment, I took another full mouth series (FMS) to re-evaluate the patient’s Grade score. Five years earlier the patient’s diagnoses was Generalized Periodontitis, Stage III (site of greatest loss 42%) and Grade C (indirect evidence calculated as 42% bone loss at the site of greatest loss ÷ 40 years of age = 1.05). In comparing her previous FMS with the new set, it was determined that “less than 2mm bone loss had occurred” in this time. Would I regress the patient’s Grade from C to B?
A: Yes, direct evidence (i.e., comparison of periapical [PA] and FMS radiographs) always trumps indirect evidence (i.e., % bone loss ÷ age). Also, your patient is five years older with less than 2mm bone loss, so let’s do the math: 43% bone loss ÷ 45 years of age = 0.95. She would be a Grade B. See Table 2: Periodontitis: Grading.
Table 2 – Periodontitis: Grading
Now here’s a question for you: If during that patient’s same periodontal maintenance appointment, she reported smoking ≥10 cigarettes a day as of six months ago, would she still regress from Grade C to B? The answer is no. Grade modifiers like smoking and diabetes always trump direct evidence (PA or FMS radiographic comparison) and direct evidence always trumps indirect evidence (% bone loss ÷ age or case phenotype). In this case the patients’ Grade score would remain at Grade C due to the impact the grade modifiers have on the patient systemically and the potential of future accelerated progression. See Table 2: Periodontitis: Grading.
Hence, it is important to ask at each appointment, during the medical health history review two questions: 1) Have you recently started smoking/using tobacco products and/or cannabis? 2) Have you recently had your sugar levels checked (HbA1c)?
- Tonetti MS, Greenwell H, Kornman KS. Staging and grading of periodontitis: Framework and proposal of a new classification and case definition. J Periodontal.2018;89 (Suppl 1):S159-S172. https://doi.org?10.1002/JPER.18-0006