direction on the same tooth the force that may be applied in the lingual direction is not so constrained because the force is applied against the bracket structure rather than the ligature or ligation module similarly the longitudinal or mesial distal forces which may be applied along the direction of the archwire may be limited or defined by the friction between the ligature or ligation module and the archwire by contrast a means for locking the archwire within the archwire slot would enhance the forces that may be exerted along the direction of the archwire likewise a means for slideably retaining the archwire within the archwire slot would allow greater flexibility than available from brackets requiring the use of ligatures or ligation modules a self ligating orthodontic bracket 10 includes two separate parts which together comprise a bracket assembly a bracket body 12 includes a base portion 14 that is secured to a patient 39 s tooth not shown with an adhesive or the like the base portion 14 supports an upper body 16 that includes a pair of tie wing portions 17 18 one portion extending in the gingival direction and the other portion oriented in the occlusal direction it is to be understood that these directions may be reversed depending upon the bracket 39 s position and the preference of the designer the upper body 16 has an archwire slot 20 that extends in a mesial distal direction when the bracket 10 is installed on a patient 39 s tooth the archwire slot 20 has a first sidewall 19 and a second sidewall 23 the second part is a sliding cover 22 that engages the upper body 16 and is selectively opened and closed over.