Does Operator-Dependent Indirect Bonding Techniques Differ from Auto-Determined Facial Axis Point?

Abstract

Objective: Brackets are orthodontic attachments bonded to a tooth for the purpose of securing an orthodontic archwire. The aim of this study was to evaluate whether human error affects bracket position errors by comparing digital and analogue indirect bonding (IDB) techniques with fully digitized IDB protocols. Methods: Thirty-six intraoral models were divided into three groups. Ten brackets were placed in each cast (incisors, canines, and premolars). In the automatic control group, brackets were placed according to facial axis point automatically calculated by Ortho Analyzer software. In the manual digital group (MDG) brackets were placed by an operator, while in the manual analogue group (MAG) brackets were placed on plaster models. Models were digitally superimposed and compared with control models (3D slicer). The linear and angular measurements were analyzed with Mann-Whitney U test and Chi-square test. Results: There were statistically significant differences in vertical, tipping, torque, and rotation for incisors and in vertical and torque for canines when comparing MDG with MAG placement. The error frequencies showed that 81.1% of brackets in the MDG were within acceptable limits, whereas only 62.5% were acceptable in the MAG group. The prevalence of accuracy in MDG was higher in all variables except tipping. Conclusion: Digital aids improved bracket position accuracy. Horizontal axis was the safest variable. Incisor of MAG showed increased discrepancy in all angular values and vertical dimension. Special consideration should be given to canines regarding vertical axis and torque errors in MAG. Angular positioning of premolars was more critical than linear positioning.