Effect of low-level laser irradiation on separator induced tooth movement

Background: Long time course of orthodontic treatment is considered as one of the major problems causing a decrease in patients’ compliance. This problem is related to the rate of tooth movement during treatment. One of the newest approved methods that affect the bone remodeling and tooth movement is the low-level laser irradiation. Objective: The aim of the present study was to evaluate the effect of low-level laser irradiation on tooth movement following the separator placement. Methods: This experimental clinical trial was carried out in dental clinics of Mashhad University during 2006-2007. A total of 30 orthodontic patients participated in this study. On the first day, the separators were placed between the 5th, 6th and the 7th teeth. Later, the low-level laser irradiation was applied to one half of each jaw for 5 days while the other half was left as control. The sides of the laser irradiation were selected, randomly. On the 6th day, the impression was taken from both arches and the distance between the teeth were measured by a leaf-like gauge. The data were statistically analyzed using paired t-test. Findings: The mean amount of the tooth movement in laser irradiated side in maxilla was 0.55±0.19 mm and in the opposite side 0.50±0.21 mm, and the difference was found to be statistically significant (p=0.031). This finding in mandible was 0.048±0.21 mm in laser irradiated side and 0.48±0.24 mm in the other side however, the difference was insignificant, statistically (p=0.86). Comparatively, the measurement of both jaws in the laser-irradiated side was 0.52±0.20 mm while it was 0.49±0.22 mm in the opposite side with no significant difference between two groups. Conclusion: Our findings suggest that the low-level laser irradiation can accelerate the tooth movement in maxilla more than that in mandible, but the difference between the mean amount of the total tooth movement in laser irradiated side and the control side was statistically insignificant.