A patient with epilepsy takes phenytoin and has developed gingival enlargement. Which factor most aggravates the condition?

Correct answer: D. Dental plaque (biofilm)

• A. Seizure frequency has no bearing on gingival enlargement.
• B. Serum drug concentration correlates only weakly and inconsistently with the degree of enlargement — plaque is the stronger determinant.
• C. The duration of the underlying epilepsy is irrelevant to the gingival response.
• D. CORRECT. PLAQUE is the principal modifying factor. Drug-influenced gingival enlargement requires the drug, but its SEVERITY correlates strongly with plaque-induced inflammation: the inflammatory infiltrate amplifies the fibroblast proliferation and collagen accumulation the drug provokes. Patients with excellent plaque control may develop little or no enlargement on the same dose. This is why meticulous oral hygiene is both the prevention and the first line of treatment.

Note: Management sequence: intensify plaque control and provide professional debridement; discuss with the physician whether an alternative anticonvulsant is feasible (though phenytoin, cyclosporine and the CCBs all carry the risk); consider chlorhexidine as an adjunct; and reserve gingivectomy or flap surgery for residual fibrotic tissue after inflammation is controlled — recurrence is likely if the drug continues and hygiene lapses.