I claim the ornamental design for an orthodontic bracket, as shown and described.
FIG. 1 is a front view of an orthodontic bracket of the present invention;
FIG. 2 is a rear view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a first side view thereof;
FIG. 6 is a second side view thereof;
FIG. 7 is a top perspective view thereof; and,
FIG. 8 is an enlarged top perspective view of the claimed area taken from FIG. 7.
The broken lines shown represent unclaimed subject matter and form no part of the claimed design. Additionally, the unevenly broken lines in the drawings define the limits of the claimed design.