Rate of Tooth Movement in the Resolution of Anterior Segment Crowding

Abstract

Background: Dental crowding presents the displacement of the contact points of teeth, impaired facial aesthetics,
compromised oral health and function, and psychological impacts. Orthodontic treatment for crowding is commenced
with thin, flexible arch wires such as; Nickel Titanium (NiTi) and Copper Nickel Titanium (CuNiTi) arch wires. This
study aimed to present the rate of tooth movement as a means of assessing resolution of crowding and to compare this
rate when using NiTi and CuNiTi archwires in the alignment phase of treatment of anterior segment crowding.
Methods: A randomized control trial among participants with a Little's Irregularity Index score (LII) of at least 4mm,
randomly allocated into 2 groups -according to wire types. Archwires of 0.014; 0.016 sequence were used for alignment;
the participants reviewed every six weeks till alignment. The rate was calculated by plotting a regression curve for the
LII scores over the review period using the Grapher™ Golden Software.
Results: The rate of alignment was similar between the arches treated with CuNiTi arch wires (0.94mm/week) and those
treated with NiTi arch wires (0.91mm/week) with no statistically significant difference. p-value =0.19.
Conclusion: Rate of tooth movement / reduction in irregularity index over time has been presented as a means of
assessment of resolution of anterior segment crowding.