Evaluation of Computer-Aided Navigation and Augmented Reality for Bicortical Mini-Implant Placement in Maxillary Expansion: An In Vitro Study

The objective of the present study was to evaluate and compare the accuracy of the computer-aided static navigation technique (NAV), augmented reality (AR) and freehand placement technique (FHT) for the bicortical orthodontic self-drilling mini-implants for maxillary skeletal expansion (MSE) appliances placed in palate. <b>Material and Methods</b>: A total of 120 bicortical orthodontic self-drilling mini-implants were placed in the palate of ten 3D printed anatomically based polyurethane models of a completely edentulous upper maxilla. The orthodontic mini-implants were randomly assigned to the following placement techniques: (A) computer-aided static navigation technique (<i>n</i> = 40) (NAV), (B) augmented reality device (<i>n</i> = 40) (AR) and (C) conventional freehand technique (<i>n</i> = 40) (FHT). Moreover, two implants were placed in each side of the midpalatal suture in every model according to the digital planification of the expander device. Subsequently, the orthodontic mini-implants were placed and postoperative CBCT scans were performed. Finally, coronal entry-point (mm), apical end-point (mm) and angular deviations (°) were calculated using a <i>t</i>-test. <b>Results</b>: Statistically significant differences were shown at coronal entry-point (<i>p</i> < 0.001), apical end-point (<i>p</i> < 0.001) and angular deviations (<i>p</i> < 0.001) between the three placement techniques of bicortical orthodontic mini-implants. Additionally, statistically significant differences were also shown between the orthodontic mini-implant positions concerning the entry point (<i>p</i> = 0.004) and angular deviation (<i>p</i> = 0.004). <b>Conclusions</b>: The augmented reality placement technique results are more accurate, followed by the computer-aided static navigation technique and the freehand technique for MSE appliances placed in palate.