Diastema Closure and Stability: Clear Aligners vs Fixed Appliances With Laser Frenectomy

Overview

This study is a prospective 2x2 factorial randomized clinical trial designed to evaluate and compare the closure efficiency and post-treatment stability of diastema associated with generalized interdental spacing (width \>= 3 mm) treated with clear aligners versus fixed orthodontic appliances, with and without adjunctive laser frenectomy. Participants are randomized into four treatment arms to assess the main effects and interaction effects of appliance modality and laser frenectomy. Stability and relapse rates are systematically tracked across active treatment, a 6-month retention period, and post-retention follow-up intervals at 6 and 8 months.

Diastema associated with generalized interdental spacing (\>= 3 mm) represents a challenging orthodontic condition with a heightened risk of post-treatment relapse. While fixed appliances provide reliable three-dimensional tooth movement control, clear aligners offer improved esthetics and patient comfort. Additionally, the role and timing of adjunctive laser frenectomy in stabilizing space closure remain controversial in generalized spacing cases. This prospective 2x2 factorial randomized clinical trial is conducted at the Orthodontic Clinics, Faculty of Dentistry, Sana'a University, Yemen. A total of 48 eligible participants are randomly allocated into four equal groups (n=12 per group): 1. Group 1: Clear Aligner Therapy with Adjunctive Laser Frenectomy 2. Group 2: Clear Aligner Therapy without Frenectomy 3. Group 3: Fixed Orthodontic Appliance with Adjunctive Laser Frenectomy 4. Group 4: Fixed Orthodontic Appliance without Frenectomy Treatment Protocols: * Clear Aligner Group: Digital intraoral scans are obtained using a Zahndent scanner. Virtual treatment planning ensures sequential space closure with root control. Aligners are manufactured by Dentalign Company (Sana'a, Yemen) and worn 20-22 hours daily. * Fixed Appliance Group: Treated using MBT prescription brackets with a 0.022-inch slot. The archwire sequence includes initial leveling with 0.012 to 0.018 NiTi wires, followed by rectangular stainless steel wires (0.016x0.022, 0.017x0.025, and 0.019x0.025 inches) for space closure and torque control. * Auxiliary Mechanics: Cervical buttons are bonded in selected teeth across aligner and fixed groups to enhance bodily movement control. * Adjunctive Laser Frenectomy: Performed using standardized laser technique following partial or complete space closure in designated groups. Retention and Evaluation: All participants follow a standardized retention protocol for 6 months post-treatment. Clinical, digital (Zahndent intraoral scanner), and radiographic (digital periapical sensor) assessments are conducted at five measurement time points: * T0: Baseline (pre-treatment) * T1: End of active orthodontic treatment * T2: End of retention period (6 months) * T3: 6 months post-retention * T4: 8 months post-retention The primary outcome is the amount of diastema relapse (mm). Secondary outcomes include total space closure, root parallelism, and relapse rates.