A self-ligating orthodontic bracket assembly has a bracket with an archwire slot extending in a mesial-distal direction for receiving an archwire a vertical slot extending into the bracket to intersect the archwire slot and a retentive boss in the vertical slot. A retentive pin slides in the vertical slot between an open position and a closed position. The pin has two parallel legs separated by a space, and a lower cross member extending between the legs. The cross member contacts the retentive boss in the open position to retain the pin in the vertical slot. Camming surfaces on the legs slidably engage the vertical slot to hold the pin in the closed position.
