Which item in the patient's medical history is cited as a periodontal risk factor?

• A. Basal cell carcinoma history
• B. Normal blood pressure
• C. Smoking history
• D. Recent surgery

Answer: (C)

Systemic factors in a patient’s medical history influence periodontal disease, and smoking stands out as a key risk factor. Smoking history increases periodontal destruction by impairing the body’s response to plaque and healing processes. Nicotine and other tobacco components cause vasoconstriction, which reduces blood flow and masking of gingival inflammation, while also impairing neutrophil and macrophage function, altering cytokine signaling, and inhibiting collagen production by fibroblasts. These effects let bacteria cause more attachment and bone loss and lead to poorer responses to periodontal therapy and slower healing after procedures. The other items listed—basal cell carcinoma history, normal blood pressure, and recent surgery—do not have the same established link to increasing the risk or progression of periodontal disease.