Control of tooth movements with the Speed system.

Steps taken to evolve the straight-wire system eventually led to the development of self-ligating brackets. The Speed system, comprehensive of bracket, wires, force, and anchorage management, is a significant evolutionary development. The design property of the fourth wall in the Speed bracket allows the Ni-Ti wire to be placed in the slot fully. Closure of the gate activates the wire for the desired type and direction of tooth movement. A sequence of round, square, rectangular wires, Ni-Ti and stainless steel, permits a complete control of the tooth position during the different phases of the orthodontic treatment. In this study, the effectiveness of the system is investigated in four groups of patients: Class II, div 1 with four first bicuspid extractions; Class II, div 2 non-extraction; Class II div 1 non-extraction in mixed dentition; Skeletal Class III skeletal treated with an orthodontic-surgical treatment plan. Treatment results were assessed using the intra-oral photographs, and radiographs taken at the start of treatment, at the end of active treatment, and in retention. Satisfactory control of tooth positions during the horizontal, mesio-distal and torque movements, both in the extraction and non-extraction cases were observed. During the course of treatment, in extraction cases where sliding mechanics are used, shifting of the anchorage from posterior to the anterior unit is possible as a result of increased forces. This shift is facilitated by the activation of the spring clip on the anterior teeth. The advantages of the self-ligating Speed system are the low levels of force used, low friction, and precise control of tooth movements.