A probing depth of 4 mm or more generally indicates

• A. A periodontal pocket associated with disease
• B. A normal variation
• C. A healthy sulcus
• D. Recession only

Answer: (A)

Probing depth measures the distance from the gingival margin to the base of the pocket or sulcus, and it reflects attachment loss and inflammation. In a healthy situation, depths are shallow, about 1–3 mm, with no bleeding on probing. When you find a depth of four millimeters or more, it usually means a periodontal pocket has formed due to destruction of the connective tissue attachment from inflammatory disease. This distinguishes it from a normal sulcus or a healthy variation, which would not reach that depth. Recession can coexist, but a depth at or above four millimeters indicates pocket formation, not simply recession alone. So, four millimeters or more generally indicates a periodontal pocket associated with disease.