Limitations
bucco-lingual angulation
The current study included a specific type of upper canine impactions. Therefore, the effects of different probabilities of the initial location, mesiodistal and bucco-lingual angulation of the impacted canines on the traction movement velocity were not evaluated. Secondly, only one type of mechanical traction means was used and the effectiveness of other traction techniques were not evaluated. Thirdly, this trial did not assess the effects of gender and age on the traction movement rate, for which a larger sample size would be necessary.