Prevalence and risk of gingival enlargement in patients treated with anticonvulsant drugs

Background: Predictors of gingival enlargement in patients treated with anti-epileptics have not been previously assessed. This study was conducted to determine, with the aid of two indices that score vertical and horizontal overgrowth, the prevalence and risk factors for gingival enlargement in patients treated with phenytoin and other anticonvulsant drugs. Materials and Methods: A cross-sectional study was conducted and data from 59 patients taking antiepileptics were compared with 98 controls. Gingival enlargement was evaluated with two indices to score vertical overgrowth [Gingival overgrowth index (GO] and horizontal overgrowth [Miranda-Brunet index (MB)] . Gingival index, plaque index, and probing depth were also evaluated. Results: The prevalence of gingival enlargement was significantly higher (P < 0.0001) for both indices in the anticonvulsants treated groups than in the control group. Gingival overgrowth was significantly higher for both indices in the phenytoin group than in the non phenytoin group. Among the possible risk factors, only the gingival index showed a significant association with gingival enlargement. For the MB index the risk of gingival enlargement (odds ratio) associated to phenytoin therapy and other anticonvulsants therapy were 52.6 (13.5-205) and 6.6 (1.5-28.2). Gingival index-adjusted odds ratios for the same drugs were 5.7 (1.3-24.7) and 18.1 (2-158), respectively. The concordance between GO and MB indices in the control group and in the phenytoin-group and non phenytoin-group showed a Kappa value of 0.773 and 0.697, respectively. Conclusion: This study reports significant differences in the prevalence and severity of gingival overgrowth in two groups of patients, one treated with phenytoin, and another treated with other anticonvulsants. Gingival inflammation is a significant risk factor for gingival enlargement in these patients.