Purpose: To determine the effectiveness of low level laser therapy applied extra orally on the reduction of orthodontic pain. Materials and Methods: Sixty dental students were voluntarily recruited for this randomized, double-blinded, placebo-controlled, prospective clinical trial. To simulate orthodontic pain, all subjects had four separators placed mesially and distally to either the right or left maxillary and mandibular first molars. Subjects were randomly allocated to one of three different groups: experimental, placebo, and control. Subjects in the experimental group received devices that emitted low level laser therapy while subjects in the placebo group received identical devices that had the output of low level laser therapy dismantled internally. Subjects in each group filled out questionnaires at seven separate time intervals regarding their pain and quality of life changes from the orthodontic separators.
Results: When measured at rest, pain increased rapidly over the first 6 hours and then began to decrease after 48 hours. When measured while chewing, pain increased rapidly over the first 24 hours and then began to decrease after 72 hours. There were no significant differences between the experimental, placebo, and control groups for pain both at rest and while chewing at any of the time points. There were also no significant differences between the three groups for changes in eating habits and consumption of analgesic drugs. Conclusion: Extra oral application of low level laser therapy is not an effective way to decrease orthodontic pain.
