What is the approximate length of the junctional epithelium (epithelial attachment)?

Correct answer: A. 2 mm

• A. Correct. The junctional epithelium (epithelial attachment) measures approximately 2 mm in length (actually the epithelial attachment averages ~0.97 mm and connective tissue attachment ~1.07 mm, together forming the biologic width of ~2 mm). Board answers typically accept 2 mm for the epithelial attachment length.
• B. 0.5 mm is less than the typical accepted range for junctional epithelium.
• C. 3 mm would indicate pathologic probing depth rather than normal junctional epithelium.
• D. 1 mm is the gingival sulcus depth, not the epithelial attachment length.