December’s Tip

First Order Artistic Wire Bends Step-in and Step-out Arch wire a .016w x .022 SS

By Dr. Adrian J. Palencar, MUDr, MAGD, IBO, FADI, FPFA, FICD

December 2020

    Step-in and step-out refers to the distance of the bracket slot from the tooth surface in a horizontal plane. Due to the difference in the thickness of teeth, certain teeth are stepped out in relation to the other teeth. For example, in the maxilla; central incisors are stepped-out, lateral incisors are stepped-in, cuspids are stepped-out, etc. However, this is all built into the brackets in preadjusted SWA. Therefore, certain brackets are thicker than others and maxillary molars have 10° – 15° distal offset.

Ribbon arch pliers are used for the First and Second order artistic wire bends, and the arch wire of choice is a .016 x .025 SS (1,700 gm of force). Certain educators prefer a .019 x .025 CNA (Beta titanium) or a .019 x .025 Multibrade. However, the author found that Stainless Steel is more resilient; it maintains the crisp artistic wire bends better and it can be retained as the final arch wire.

IMG_3043.JPGThe orientation of the Ribbon arch pliers is perpendicular to the arch wire. The basic rule of First order artistic wire bends is:

  1. If the side of the crown of the tooth should be stepped-out – bend-in the arch wire
  2. If the side of the crown of the tooth should be stepped-in – bend-out the arch wire
  3. All artistic wire bends are around 15°, except maxillary molars 25° (distal offset)

These artistic wire bends may be accentuated on subsequent appointments.

             A misaligned mandibular right lateral was attempted to correct by placing a 15° mesial step-out; however, the tooth did not align properly. Therefore, we placed a 15° distal step-in and the problem was resolved in one month.  This double First order artistic wire bend is referred to as “Z” bend.  Now, there are two choices:

  1. Maintain the same arch wire for 3 months and finish the case, alternatively;
  2. Place a heavier finishing SS arch wire (i.e. a .018 x .025 or a .019 x .025). However, both first order artistic wire bends must be meticulously reproduced and held for additional 2 months

References

  1. Nakajima E., Manual of Wire bending Techniques; 56 – 65
  2. Rondeau Seminars “Case Finishing” manual; 64 – 80
  3. Andrews L. A.; Straight Wire the Concept and Appliance