**Core Concept**
A pseudo pocket is a clinical term used in periodontal assessment to describe a gingival pocket that appears deep but is not true periodontal pocket. It results from inflammation of the gingiva without actual bone loss, and the base of the pocket lies on the gingival epithelium or cementum, not alveolar bone.

**Why the Correct Answer is Right**
In gingivitis, the gingival tissues become inflamed and swollen, leading to a deepened gingival sulcus. This deepened space is called a pseudo pocket because the base of the pocket lies on the cementum or epithelium, not on alveolar bone. There is no destruction of the alveolar bone, and the condition is reversible. The pocket depth is due to inflammation, not periodontal disease progression.

**Why Each Wrong Option is Incorrect**
Option A: The base of the pocket lies on cementum in true periodontal pockets, not pseudo pockets. In pseudo pockets, it lies on the gingival epithelium, not cementum.
Option C: Periodontitis involves actual bone loss and is characterized by true periodontal pockets with base on alveolar bone. Pseudo pockets are not seen in periodontitis.
Option D: The base of a pseudo pocket does not lie on alveolar bone; this defines a true periodontal pocket, not a pseudo pocket.

**Clinical Pearl / High-Yield Fact**
Pseudo pockets are a hallmark of early gingivitis and can be mistaken for periodontal pockets. Recognizing this helps in early intervention and prevents progression to periodontitis. Always assess for bone loss and epithelial attachment to differentiate between pseudo and true pockets.

✓ Correct Answer: B. Gingivitis