Till date, several investigators have tested different materials but none of these has been shown to possess the requisite properties of an ideal root canal filling material for primary teeth, especially about the major desirable property of having a rate of resorption matching that of the physiologic root resorption of the primary teeth.It has been found that the current obturating materials for primary teeth while providing satisfactory clinical results still need to be modified to suit the various clinical situation that is encountered. Due to the drawbacks of Zinc oxide eugenol material,...

"The possibility exists that different functional appliance designs act in dissimilar ways and are not directly comparable. Variation in appliance action - such as the amount of mandibular advancement, types of construction bites, and prescribed time of wear also brings about different results. Furthermore, the duration of treatment varies from individual to individual. Despite all of these problems there is still convincing evidence supporting the concept that functional appliances do create an orthopaedic effect in specific individuals. Growth and development, which affect considerable...