Orthodontic tooth movement is a complex process that needs to be done with a detail knowledge of various factors affecting it in order to achieve optimal and needful movement of teeth while treating different kinds of mal-occlusion. OTM can occur rapidly or slowly, depending on the physical characteristics of the applied force, and the size and biological response of the PDL(Periodontal ligament). The orthodontic forces can be heavy or light, which causes rapid or slow tooth movement. Therefore, optimal orthodontic force plays an important role for maximum tooth movement to occur with minimal tissue damage and discomfort to patient.