Objective: The purpose of this study is to evaluate the efficacy of CO2 laser vaporization therapy for oral lichen planus (OLP) refractory to conservative treatments. Methods: The study group comprised 16 patients with clinically and histologically diagnosed OLP. They underwent conservative treatment for 3 months using an adrenal cortex hormone ointment and azulene sulfonate sodium hydrate gargle. Patients who showed no improvement with conservative treatment underwent CO2 laser vaporization therapy (3 W, continuous-wave mode). The assessment was performed using the numerical rating scale (NRS) as a subjective indicator and the Thongprasom sign score (TSS) as an objective indicator of OLP. These two scales were recorded during examinations performed before treatment and then at 7 days, 1, 3, and 6 months, and 1 year after irradiation. Differences between preirradiation and each point of time after irradiation were tested by Wilcoxon's signed-rank tests. Results: Laser irradiation was administered to 9 patients with 11 sites. The NRS score and TSS decreased at all 11 sites (100%) and 10 sites (90.9%) at 1 year after irradiation compared with preirradiation scores. The NRS score and TSS were statistically lower (p < 0.05) at 1 and 3 months (short-term) and 6 months and 1 year (mid-long-term) after irradiation than the preirradiation scores. There were no patients with malignant transformation during the study period. Conclusions: These single-arm clinical trial results show the efficacy of CO2 laser vaporization therapy for OLP refractory to conservative treatment.
Keywords: laser vaporization; oral lichen planus; single-arm clinical trial.