A Comparative Study to Evaluate the Effectiveness of 3D Digital Models and Study Cast to Measure Anteroposterior Anchorage Loss in Patients Treated with Preadjusted Edgewise Appliance

Anchorage loss is an important parameter in controlling the outcome of orthodontic treatment. Lateral cephalogram and study model analysis are routinely used to monitor anchorage loss. Study is to evaluate the effectiveness of 3D digital model and study cast to measure maxillary molar anchorage loss in patients treated with fixed orthodontic appliance. A total of 31 high anchorage patients who were treated with pre adjusted edgewise appliance for their malocclusions were included in the study. Amount of horizontal anchorage loss was measured by two methods: Study cast and 3D digital model super imposition. The anterior palatal rugae area was taken as a reference point for comparative measurements. Paired t-test was performed to compare the mean values of anchorage loss measured on both methods. When we compared the mean anchorage loss of two methods, it was found that there were no statistically significant differences observed for both the right side (t= 0.513, p>0.05) and left side (t= -0.081, p>0.05). The spearman correlation between two methods showed a very strong correlation in both right (r=0.919) and left side (r=0.906) which was statistically significant (p <0.001). The present study shows that the measurement of anchorage loss using 3D digital superimpositions is equally reliable as that of study models. Thus, 3D digital models present as an alternative method to the measurement of anteroposterior anchorage loss.