Periodontitis — ORE Part 1 MCQ

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ModeratePeriodontologyPeriodontitisORE Part 1

A 50-year-old man presents with generalised horizontal bone loss affecting all teeth. Probing depths range from 4–6 mm with generalised bleeding on probing. Radiographically, he has lost 15–33% of alveolar bone height. According to the 2017 classification, what is the stage of his periodontitis?

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Correct answer: E — Stage II

According to the 2017 World Workshop classification (adopted by UK SDCEP), periodontitis staging is based primarily on radiographic bone loss extent and severity. Stage II is defined by radiographic bone loss of 15–33% with horizontal pattern and no tooth loss. The patient meets all Stage II criteria: bone loss is 15–33% (the threshold discriminator), is horizontal (typical of early-to-moderate disease), and has probing depths ≤6 mm. Although probing depth reaches 6 mm, this does not override the bone loss extent criterion; Stage III requires radiographic bone loss extending to the middle third of the root (>33% extent), which this patient does not have. Stage I requires <15% bone loss. The radiographic extent of bone loss, not probing depth alone, is the primary staging determinant.

Reference: SDCEP Prevention and Treatment of Periodontal Diseases in Primary Care (periodontalcare.sdcep.org.uk), 2024; 2017 World Workshop Classification of Periodontal and Peri-Implant Diseases, https://www.periodontalcare.sdcep.org.uk/guidance/diagnosis/establishing-a-periodontal-diagnosis/periodontitis/