In spite of the variety of appliance designs available to the orthodontist; the techniques of either closing loops or sliding mechanics have their advantages and disadvantages. In this dissertation we will be discussing various theoretical aspects of space closure as well as some methods to close space sites, based on biomechanical concepts. In spite of the variety of appliance designs available to the orthodontist; the techniques of either closing loops or sliding mechanics have their advantages and disadvantages. In this dissertation we will be discussing various theoretical aspects of space closure as well as some methods to close space sites, based on biomechanical concepts.