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Stage III Grade B periodontitis — ORE Part 1 MCQ

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HardPeriodontologyStage III Grade B periodontitisORE Part 1

A 49-year-old patient has interdental clinical attachment loss at multiple non-adjacent molars, probing depths up to 7 mm, and radiographic bone loss extending to the middle third of the root at the worst affected site. The bone loss at that site is estimated at 35% of root length. No teeth have been lost because of periodontitis. There is no smoking history or diabetes. Which periodontal diagnosis is most appropriate?

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Correct answer: A — Stage III Grade B periodontitis

The diagnosis is Stage III Grade B periodontitis. Under current SDCEP UK implementation, staging is determined from the worst affected site: bone loss into the middle third of the root is Stage III. Stage IV requires apical-third bone loss or, where known, tooth loss from advanced periodontal bone loss. Grade is calculated from worst-site percentage bone loss divided by age: 35/49 = 0.71, which lies within the Grade B range of 0.5–1.0. The absence of smoking and diabetes is relevant to risk assessment but does not itself establish grade. Stage I is incompatible with this severity of bone loss. Gingivitis does not cause attachment or radiographic bone loss. Necrotising disease would require characteristic necrotic, ulcerated interdental tissues and an acute clinical presentation.

Reference: Scottish Dental Clinical Effectiveness Programme (SDCEP), Prevention and Treatment of Periodontal Diseases in Primary Care, 2nd edition: “Periodontitis—Staging” and “Grading”, 2024. https://www.periodontalcare.sdcep.org.uk/guidance/diagnosis/establishing-a-periodontal-diagnosis/periodontitis/