Which term describes the distance from the CEJ to the gingival margin used in recession calculations?

• A. PD
• B. CEJ-GM distance
• C. GM-CEJ distance
• D. GM

Answer: (C)

Gingival recession is quantified by the distance the gingival margin has moved from the cementoenamel junction. The term used to describe that measurement is GM-CEJ distance, since it denotes the gap between the gingival margin (GM) and the CEJ. This distance is what you use in recession calculations to express how much root surface exposure there is. Probing depth (PD) measures the depth of a sulcus or pocket, not the recession, and the margin alone (GM) isn’t a distance; CEJ-GM distance would refer to the same gap but the common notation in recession work is GM-CEJ distance, which clearly communicates that you’re assessing recession.