Comparing Ligation Methods During Canine Retraction Stage Using Conventional Brackets

The goal of this Randomized Controlled Trial (RCT) is to determine the most effective way to tie the main wire to the regular orthodontic brackets during the stage of orthodontic treatment where the canines are retracted. This study is for orthodontic patients aged 16 years and older who need to have their canines retracted into spaces where other teeth have been removed.

The main questions it aims to answer are:

1. What is the effect of different ways of tying the wire to the braces on how much the maxillary canine moves back using conventional brackets? 2. How do various ways of tying the wire influence unwanted movements of the maxillary canines-specifically rotation, tipping, and extrusion? 3. What is the effect of these different tying methods on how much the back molar teeth shift forward (this is called "anchorage loss") while the maxillary canine is being pulled back?

Researchers will compare three different ways of tying the wire to the braces to see if they differ in the amount of maxillary canine retraction, three-dimensional positional changes (rotation, tipping, and extrusion), and anchorage loss of maxillary first molars:

* Group A: Uses an elastic power chain that wraps around all four parts (wings) of the brace. * Group B: Uses thin stainless-steel wires (ligatures) to tie the brace first, then an elastic power chain is placed over these wires, also wrapping around all four parts of the brace. * Group C: Uses small elastic rings on the two front parts (mesial wings) of the brace, and an elastic power chain on the two back parts (distal wings) of the brace.

Participants will consist of orthodontic patients aged 16 years and above from the Postgraduate Orthodontic Clinic, Kulliyyah of Dentistry, IIUM, Kuantan, who require extraction of one or both maxillary first premolars, are planned for maximum anchorage using a Nance appliance, need at least 4mm of maxillary canine retraction, and have good oral hygiene.

Participants will:

* Undergo screening and provide written informed consent for participation. * Receive a comprehensive orthodontic examination, including photographic records, impressions, and radiographs. * Have molar bands fitted and a Nance button fabricated and cemented, followed by dental extractions of maxillary first premolars. * Undergo bond-up with conventional stainless-steel brackets and initial archwire placement. * Progress through an alignment and levelling phase using progressively larger archwires, culminating in a 0.019 x 0.025-inch stainless steel archwire. * At baseline (T0) and subsequent 4-week follow-up intervals (T1, T2, T3), have intraoral three-dimensional scans taken after archwire removal. * Receive canine retraction using elastomeric power chains delivering a standardized 150g force. This is done as a two-step retraction, where the canine is retracted in isolation. * Continue to receive full orthodontic treatment to completion even after the data collection period ends at T3.