US Patent 7140875 Orthodontic bracket with reinforced tiewings

An orthodontic bracket has at least one tiewing and a groove behind the tiewing for receiving a ligature. The groove extends along a path that is inclined in a direction away from an archwire slot of the bracket as a central, upright reference plane bisecting the bracket is approached. In addition, the depth of the groove decreases as the reference plane is approached. Preferably, an outermost edge of at least one tiewing is inclined in a direction away from the archwire slot as the adjacent side of the bracket is approached. The tiewing is less likely to fracture during the course of orthodontic treatment, and yet the ease of ligation is not compromised.