Diphenylhydantoin-induced gingival hyperplasia: its response to changes in drug dosage.

Changes in gingival hyperplasia were studied in 48 patients treated for epilepsy with diphenylhydantoin (DPH) over a two-year period. During this time changes in the dose of DPH were made in some patients in order to increase control of seizures or decrease side-effects: in 27 patients the dose was increased, in nine it was decreased and in 12 the dose remained unchanged. It was found that the severity of gingival hyperplasia varied directly with both the dose and serum level of the drug.