# A Review of CO\({}_{2}\) Laser-Mediated Therapy for Oral Mucosal Lesions
## 3 Results
### CO\({}_{2}\) Laser Treatment in the Case of Oral Leukoplakia  
In a clinical study published by [PERSON] et al. (2016), 32 patients with 44 oral leukoplakia lesions were treated using CO\({}_{2}\) laser vaporization. The follow-up period was 6-12 months, and some etiological factors (smoking, alcohol consumption, dental trauma, etc.) were also recognized and eliminated if possible. While forty lesions (90.9%) achieved local control after one laser session, a rate of 97.7% was obtained after the second or third vaporization. The recurrence rate was 9.10% and one case (2.27%) suffered from malignant transformation after CO\({}_{2}\) laser surgery [32]. A clinical trial published by [PERSON] et al. (2020) investigated the efficiency of CO\({}_{2}\) laser ablation of oral leukoplakia on 30 patients (with a total of 33 oral leukoplakia lesions). The lesions were divided into three groups for study, as follows: (A) 11 lesions in 11 patients, for which the laser ablation was performed for the entire lesion without extension of margins; (B) 11 lesions in 8 patients, for which ablation was done with a minimum extension of 3 mm of margins; (C) 11 untreated lesions in 11 patients with no treatment approach, with a periodic 6-month follow-up. The results revealed complete healing of 13 lesions in Groups A and B, and complete regression in the case of three lesions in Group C. However, 6 out of 9 lesions in Groups A and B that showed recurrence after 6 months also showed initial recurrence after 3 weeks of laser ablation. Complete healing occurred in 87.5% of patients with no smoking history, while for ex-smoker patients, complete healing was observed in 42.8%. With overall recurrence rates of 45.5% in Group A and 36.4% in Group B, the authors concluded that the recommended extension of the margins should be at least 3 mm in width [33]. A retrospective study published by [PERSON] et al. [34] assessed the demographic data and pathological results of 111 patients (80 males and 31 females) who underwent CO\({}_{2}\) laser surgery for tongue leukoplakia between 2002 and 2019. The results showed that the prevalence of ventro-lateral tongue leukoplakia was higher than that of dorsal tongue leukoplakia (\(p<0.001\)). The follow-up time was 3.74 \(\pm\) 4.19 years. Fifteen patients had postoperative recurrence (13.51%), while four patients (3.6%) developed malignant transformation. The authors concluded that, while dorsal tongue leukoplakia was not as frequently encountered clinically as ventro-lateral tongue leukoplakia, the therapeutical outcomes were comparable among the two types of lesions, in terms of postoperative recurrence and postoperative malignant transformation. [PERSON] et al. [35] performed a retrospective study on elderly patients (older than 65 years) suffering from oral leukoplakia (OL) who received surgical excision of OL lesions with CO\({}_{2}\) laser. A total of 69 subjects were included in the study, with a mean age of 71.2 \(\pm\) 4.9. The univariate statistical analysis revealed that some factors, such as morphology, pathology, and area of the lesion, were associated with postoperative recurrence. In the multivariate logistic regression model, the lesion's pathology and area were predictive factors for recurrence. Malignant transformation occurred in eight subjects (11.6%). [PERSON] et al. (2020) performed a study on 20 patients (44 oral leukoplakia lesions) treated with CO\({}_{2}\) vaporization, with a follow-up of 6 to 12 months (a mean of 9 months). Their results revealed that forty lesions were considered cured after the first laser session, two lesions were cured after the second session, and one lesion was considered treated after the third session. The rate of recurrence was 2.27% (one case) for this study [36]. In order to assess the treatment outcomes of the CO\({}_{2}\) laser compared with traditional cold knife surgery, three studies were selected. [PERSON] et al. [37] guided a retrospective study, which included 73 patients with vascular malformations, oral leukoplakia, and verrucous nevus.