Dilantin (Phenytoin) is a anticonvulsant drug used to treat epilepsy and other neurological disorders. This drug has a 50% incidence (Angelopoulos and Goaz, 1972) of causing gingival hyperplasia. Other anticonvulsant drugs such as Carbamazepine (Tegretol), and Valporic acid (Depakene, Depakote) have the potential to induce gingival hyperplasia, but it is rare (Dahllof, et al., 1993; Dongari, et al., 1993).
Some studies indicate that this drug depletes the vitamin folic acid. Consequently, preliminary studies and case reports have been done that supports this hypothesis. Specifically, rinsing the mouth with a solution of folic acid 1 mg/ml twice a day has been shown to be effective. The problems that I have had prescribing this are involved with getting a pharmacist to make this formulation and patient compliance. Consequently, I have had patients get folic acid over the counter, and simply having them dissolve the tablets in their mouths (one twice a day) and swishing it around.
Clinically, it is necessary to remove the excess tissue, teach excellent plaque control and maintain on a two to three month cleaning schedule.
The two photos that follow illustrate how severe the tissue can respond to Dilantin.

Before After
This patient was a 21-year-old male student taking Dilantin 200 mg at bedtime. His chief complaint was "gums" that bleed, and was unsightly making him self-conscious when dating.
As can be seen, the removal of the excess tissue revealed several areas of decay that were later restored. The decay occurred secondary to not being able to keep the teeth plaque free (i.e., the hyperplastic gingiva prevented the toothbrush bristles from reaching the teeth to clean them).
In most cases, excellent home care will prevent this type of tissue response. However, there are situations where the patient cannot maintain themselves properly due to physical or mental limitations. When possible, gingival hyperplasia will resolve if placed on a different medication, such as carbamazepine, or valporic acid. However, the risk of switching to a different medication is not controlling the seizures. Working with the neurologist is very important.
It is important to realize that this is an example of a severe tissue reaction. Most periodontal diseases have minimal or no obvious symptoms. It is often a "silent disease." In most cases of periodontal disease, it is necessary to measure the spaces, called pockets, around the teeth and correlate that with X-rays to determine the extent of the disease process.
Copyright © 2002 Dale R. Johnstone, DDS