A Retrospective Study to Evaluate the Intra-Arch Dimensional Changes in Moderate Crowding Cases Treated Non Extraction with a Passive Self-Ligation Appliance

[Background]Non-extraction treatment protocols are better accepted by patients as well as clinicians. Among the techniques and mechanics with the potential to facilitate non-extraction treatment includes headgears, fixed sagittal correctors, transverse expansion screws and self-ligating systems.[Objectives]To evaluate the intra-arch dimensional changes in moderate crowding cases, treated non-extraction with a passive self-ligating (Damon 3MX) appliance using digitized models and lateral cephalograms.[Methods]A total of 20 patients (age group of 15 - 18 years) who had undergone non extraction orthodontic treatment with the Damon 3MX appliance were selected. All the pre-treatment and post-treatment dental stone models of maxillary and mandibular arches were scanned using 3D digital scanner (Maestro 3D, Greatlakes, USA) and were converted into digital models. Various parameters undertaken were measured digitally on the computer in millimetres. Cephalometric tracings of pre and post treatment cephalograms were performed using digital cephalometrics (Nemo Ceph, version 6.0, Spain). Statistical analysis was performed using t-test.[Results]More transverse expansion was observed in the region of 1^st and 2^nd premolars as compared to the inter-canine and inter molar region in maxillary and mandibular arch. However a decrease in arch depth was observed in maxillary arch but arch depth of mandibular arch was found to be increased. There was significant increase in anterior proclination in both maxillary and mandibular arches.[Conclusions]Passive self-ligating system causes a significant increase in transverse width in both maxillary and mandibular dental arches.