IRCT2015030921406N1 IRCT 2015-06-16 Orthodontics research center evaluation the effect of low energy laser on rate of tooth movement during orthodonthic treatment evaluation the effect of low energy laser irradiation on the rate of mandibular molar protraction in orthodontic patients 2015-04-30 anticipated 56 Complete https://irct.ir/trial/18768 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Used, Assignment: Single, Purpose: Treatment. N/A Injury, poisoning and certain other consequences of external causes. Intervention 1: intervention group: at first cession T-loop will be activated for first mandibular molar protraction. at same time irradiation will be done at mocusa of left first molar in mesiobuccal, mid buccal, disto buccal, mesio lingual, mid lingual, disto lingual and mesial of first molar. every point will be irradiated for 45 seconds. this will be repeat at the end of first and second month. Intervention 2: control group: at first cession after T-loop activation on both side of patient, on left first molar we will put laser tip on the same points of right first molar but will not push the pedal. we will use the dark shield over the laser tip and the person who will activate loop will be different from person who push laser pedal. consequently first person will be blind to irradiation side. this will be done as well as laser side and will be repeated at the end of first and second month.