Lp. Lotzof et al., CANINE RETRACTION - A COMPARISON OF 2 PREADJUSTED BRACKET SYSTEMS, American journal of orthodontics and dentofacial orthopedics, 110(2), 1996, pp. 191-196
Before the 1970s, Begg and Edgewise appliances were the most commonly
used appliances in orthodontics. With the introduction of preadjusted
appliances, many have made claims of superiority. These claims are oft
en unsubstantiated, as few, if any, have ever been tested in a control
led, prospective in vivo study. The purpose of this study was to compa
re the time required to retract canine teeth by using two different pr
eadjusted bracket systems (Tip-Edge, TP Orthodontics, LaPorte, Ind,, v
ersus A-Company straight wire, Johnson and Johnson, San Diego, Calif,)
in a human sample. Anchorage loss as a result of this movement was al
so evaluated. A sample of 12 patients was randomly selected from the n
ew patient pool at the postgraduate orthodontic clinic of Montefiore M
edical Center. All patients required the removal of first premolars in
one or both arches as a part of their orthodontic treatment. The rate
of retraction and anchorage loss were evaluated. Paired t tests were
performed separately for the rates of retraction and anchorage loss, T
he mean rates of retraction were 1.88 mm per 3-week period and 1.63 mm
per 3-week period for the Tip-Edge and A-Company brackets, respective
ly. There was no statistically significant difference in the rates (p
> 0.05). The mean anchorage loss was 1.71 mm for the Tip-Edge bracket,
and 2.33 mm for the straight wire bracket. The difference in the amou
nt of anchorage loss was inconclusive as the sample size was too small
(power was 10%).