Outcome of photodynamic therapy on orthodontic leveling and alignment of mandibular anterior segment: A controlled clinical trial.

BACKGROUND: Photodynamic therapy (PDT) is a non-invasive approach that has drawn attention to accelerate orthodontic tooth movement (OTM). However, no studies have been published that evaluates the outcome of PDT on orthodontic leveling and alignment. Therefore, the present study aimed to evaluate outcome of PDT on orthodontic leveling and alignment of mandibular anterior segment. MATERIALS AND METHODS: Thirty patients (18 females and 12 males) were included who had moderate mandibular crowding with average age was 19.23 +/- 3.1 years. They were randomly divided into a control group without PDT intervention and a laser group. All patients followed non-extraction approach using one category of fixed appliance and matching NiTi archwire sequence for 3 months. In PDT group, methylene blue mediated gallium aluminum arsenide laser was applied with 635 nm, 6.5 J/cm(2), for 10 s at 10 points (0.2 J/point) started immediately after first wire then at days 3,7,14 of first month and repeated for additional 2 months. Relief of crowding was assessed by Little;s irregularity index (LII) scores after 4, 8, and 12 weeks through scanned 3-dimensional models via a software. RESULTS: Both groups showed improvements in mandibular crowding as evidenced by significant decreases (p </= 0.001) in LII scores during all observation intervals with no significant differences (p > 0.05). Moreover, the alignment;s rate showed no significant differences between groups. CONCLUSION: PDT produced a negligible effect concerning alignment of crowded mandibular anterior teeth. Besides, OTM's rate at different observation intervals showed an equivalent pattern either with or without PDT.