The effects of third-order torque and self - Saint Louis University

specific angles relative to the plane of the template to
enable torque-placement in the second-premolar slot (Figure
3-2). The seventh template was left uncut to place zero
degrees of torque at the second premolar. Each template as
a whole was initially flat and shaped to place the canine
and first-molar attachment-slots in zeroed first- and
second-order positions, while also controlling the location
of the second-premolar bracket-slot (Figure 3-3). The
second-molar tube was aligned with a 0.021- by 0.025-inch,
straight wire-segment cantilevered from the three adjacent
attachment-slots set at zero degrees of torque.
Each “test specimen” consisted of two brackets, two
molar tubes and a stainless steel archwire. Affixed at the
first-molar site was a self-ligating first-molar tube with
a facial slide mechanism and a 0.022-inch slot (SLBUCCAL,
Ormco Corporation, Glendora, CA; Figure 3-4). This crown-
attachment can be opened like a standard converted molar-
tube; it permitted the insertion of the slot-positioning
template, and the slide was closed during testing to enable
its functioning as a standard unconverted four-walled
buccal tube. The second-molar attachment was a 0.022-inch
slot, maxillary single tube (Part Number 68-172-82; GAC
International, Bohemia, NY). The archwires were 0.019- by
58