The goal of this randomized clinical study is to compare the effectiveness of stainless steel (SS) and titanium-molybdenum alloy (TMA) wires for maxillary canine retraction using TAD-supported segmental mechanics. The main question it aims to answer is:

Which wire material, stainless steel or titanium-molybdenum alloy, provides better outcomes in maxillary canine retraction when used with TAD-supported segmental mechanics? Researchers will compare SS reverse-closing loops with TMA reverse-closing loops to evaluate differences in the rate of canine retraction and canine angulation changes during orthodontic space closure.

Participants will:

• Receive mini-implants/TADs on both sides of the maxillary arch.
• Receive a stainless steel reverse-closing loop on one side and a TMA reverse-closing loop on the contralateral side.
• Receive the same standardized force of 150 g on both sides.
• Visit the clinic every 4 weeks for a total duration of 4 months.
• Undergo OPG radiographs before retraction and after the 4-month study period to assess canine angulation.

Background: Canine retraction is vital in orthodontic treatment, especially in first premolar extraction cases. Stainless steel (SS) and titanium-molybdenum alloy (TMA) wires are two most commonly used materials in segmental canine retraction with loop mechanics. Temporary anchorage devices (TADs), provide absolute anchorage.

Objective: To assess and compare maxillary canine retraction using SS and TMA wire in TAD-supported segmental mechanics.

Materials and Methods: After taking IRB approval, informed consent and assent a randomized clinical study will be conducted with 16 participants aged 15 to 35 years who require maxillary 1st premolar extraction on both sides to alleviate crowding or protrusion at Orthodontics department in Bangladesh Medical University (BMU). Each participant will receive a TAD on the same anatomic location with reverse closing loop (RCL) of SS wire 0.016 × 0.022" on one side and RCL of TMA wire 0.016 × 0.022" on contralateral side. Same 150 g force will be standardized with Dontrix gauge for both side. Rate of canine retraction will be measured intraorally with a digital slide caliper at four-week intervals for a total of four months. Canine angulation will be measured in OPG before retraction and after four months study period.

Statistical Analysis Plan: Data normality will be tested to select parametric or non-parametric analyses with P value <0.05 as significant. All the analyses will be performed using SPSS (version 30.0, IBM, New York, USA).

Expected outcome: TMA wire other than SS wire may be more effective in maxillary canine retraction from TAD-supported segmental mechanics providing scientific rationale for material choice.

Inclusion Criteria:

• Participants aged 15 to 35 years.
• Both male and female participants.
• Patients with all permanent teeth present, excluding third molars.
• Patients requiring extraction of both maxillary first premolars
• Patients with Class I or Class II molar relationship requiring maximum anchorage.
• Patients already undergoing fixed orthodontic treatment with a 0.018-inch Roth preadjusted appliance system.
• Maxillary canines aligned, symmetrical, and upright before the study.
• Patients in the leveling and alignment stage before canine retraction.

Exclusion Criteria:

• Missing or absent upper premolars.
• Previous orthodontic, orthognathic or reconstructive treatment.
• Systemic disease contraindicating dental implant placement.
• Use of systemic drugs or presence of systemic illness.
• Compromised periodontal condition.
• Use of anti-inflammatory therapy.
• Smokers.
• Pregnant female participants.

Confidentiality and privacy will be preserved by utilizing unique identifying codes instead of personal identifiers