**Question:** Clinical signs of occlusal trauma include all except:

A. Gingival inflammation (erythema and edema)
B. Tooth mobility (increased mobility of the tooth due to ligament damage)
C. Pulpal necrosis (death of dental pulp cells)
D. Caries (decay or destruction of tooth structure)

**Correct Answer: D. Caries**

**Core Concept:** Occlusal trauma refers to trauma caused by improper tooth contact or occlusion. Clinical signs of occlusal trauma typically involve inflammation and damage to dental tissues.

**Why the Correct Answer is Right:** Caries, or dental decay, is a separate entity from occlusal trauma and does not represent a direct consequence of improper occlusion. Caries results from bacterial infection and demineralization of tooth enamel and dentin, leading to cavities.

**Why Each Wrong Option is Incorrect:**

A. Gingival inflammation (erythema and edema) - This is a common and relevant sign of occlusal trauma, as it represents the body's response to tissue trauma and inflammation.
B. Tooth mobility (increased mobility of the tooth due to ligament damage) - This sign indicates damage to periodontal ligament, which is directly related to improper occlusion and dental trauma.
C. Pulpal necrosis (death of dental pulp cells) - This is a consequence of severe occlusal trauma, as it represents the death of dental pulp cells due to hypoxia, ischemia, or infection.

**Clinical Pearl:** A thorough clinical examination should focus on assessing gingival inflammation, tooth mobility, and pulpal necrosis when evaluating signs of occlusal trauma. Caries, while important to diagnose and treat, is not a direct consequence of occlusal trauma, so it is not included in this list of clinical signs.