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

maxillary- incisor brackets so that finishing with 0.019- x
0.025-inch wires will still result in optimal root
positioning. 102
The vendor-stated sizes of both the wire and the slot
are nominal dimensions because of manufacturing tolerances
that exist in the fabrication processes. Actual dimensions
are not reported by the vendor. Sebanc et al. 98 measured
dimensions of bracket-slots with a traveling microscope and
the dimension(s) of various orthodontic-wire cross-sections
with a micrometer. They found that slot dimensions were
generally larger than their nominal values. Actual wire
dimensions were generally found to be equal to or smaller
than nominal sizes, but all were within 0.0005 inches.
Meling and Ødegaard. 100 found a range of ±0.0005 inches in
actual wire heights across the wires of seven wire-vendors.
Kusy and Whitley 94 measured archwires and bracket-slots, and
they found that 30% of the wire specimens were larger than
suggested by their nominal dimension(s). Of the bracket-
slots tested, 15% of the measurements were smaller than the
vendor-stated values. The abilities of the manufacturers,
or lack thereof, to accurately produce wires of stated
dimensions can affect the amount of torque expressed in the
bracket-slots. 101,103
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