The present invention relates to a new orthodontic bracket, comprising a bracket base 1, characterized in that there is a mesial groove 2 and a distal auxiliary groove 3 in parallel laterally located on the upper and lower sides of the outer surface of bracket base, wherein the said mesial groove 2 and the said distal auxiliary groove 3 have an archwire slot of mesidal groove 2 and an archwire slot of distal auxiliary groove 3 which are lateral and parallel, respectively, and the vertical interval between the center lines of the archwire slot 2 and archwire slot 3 is 0.086-0.196 inches. The present invention also involves a self-ligating cover of buckle type based on double groove, breaking the restrictions of current self-ligating bracket on the groove archwire size to be inserted. A self-ligating bracket with an adjustable extender in the mesial groove is further described herein, realizing the switch between two different contact forms of the archwire and the bracket groove. The bracket as set forth herein is able to effectively control the tooth movements in three-dimensional directions, improve the effect on tooth position and orientation adjustments and shorten the treatment duration.
