Effectiveness, Patient Acceptance, and Cost Estimation of 3D-printed Retainer Compared to Hawley Retainer in Expansion Case: a Randomized Controlled Trial

Expansion of the arches is generally considered highly unstable and prone to relapse regardless of the type of expansion. Retention appliances play a vital role in preserving these changes. Hawley retainer users often avoid wearing them due to speech difficulties and less aesthetic appeal. They are also more prone to breakage, costlier, and require more labour. Despite the relatively recent introduction of 3D-printed retainers, they offer potential advantages in orthodontics, including the accuracy of digitally scanned images, reduced labour and material costs, and improved patient comfort. While 3D-printed retainers are quite new, most studies focus on laboratory testing of their mechanical properties, there is limited evidence directly comparing their effectiveness in retaining arch width increases, patient acceptance, and cost estimation. This knowledge gap creates uncertainty about the optimal choice of retainer for long-term stability, necessitating a comparative assessment of their performance. This study addresses this knowledge gap by evaluating the retention of arch width increases achieved using Hawley retainers versus 3D-printed retainers

Inclusion Criteria: * Patients aged 16 years or older at the time of debonding * Treatment plan of extraction or non-extraction followed by straight wire appliances in the upper arch only or both arches * Undergone expansion treatment in the upper arch causing an arch width increase of 3-10mm, either using a Quadhelix, expansion with archwires, or URA with midline screw * Had pretreatment dental cast * Had no chronic medical condition. Exclusion Criteria: * Cleft lip and palate * Chronic medical conditions * Broken teeth or bubbles on study model at site of measurement.