Assessment of Myeloperoxidase Levels In Relation to the Nature and Duration of Orthodontic Forces – An In vivo, Split Mouth Study

Abstract

To assess the change in the myeloperoxidase levels(MPO)in the gingival crevicular fluid(GCF) at different time intervals during the course of orthodontic treatment with the application of intermittent and continuous forces. It was an interventional, split mouth study done on twenty patients scheduled to undergo fixed orthodontic treatment with therapeutic extractions of the first premolars.Mini implant assisted enmasse retraction was done after leveling and aligning of the arch.Continuous force with the help of Niti coil spring was used in the first quadrant and intermittent force with an elastomeric chain was used in the second quadrant. MPO was collected from the GCF using What man’s paper at baseline,1 week and 2 weeks after the application of retraction forces.The levels were assessed using a commercially available ELISA kit. Mean MPO activity was increased in the GCF of all the patients at 1 and 2 weeks after retraction,in both quadrants.At 2 weeks, MPO levels at the intermittent force application site were found to be significantly higher than those at the site of continuous force application. Myeloperoxidase is a useful marker to assess inflammation associated with orthodontic tooth movement.Intermittent forces cause a higher degree of inflammation as compared to continuous forces.