(19) Exploring Dynamic Navigation For Palatally Impacted Canine Uncovery Surgery

Introduction: The objective of this study was to compare the exposure/uncovery of palatally impacted canines via the use of dynamic navigation guidance to the traditional freehand approach. Outcomes evaluated include the time to plan and perform exposure, area/size of initial access to locate the impacted tooth and the final size of the osteotomy to completely uncover the impacted tooth

Methods: In order to simulate various frequently encountered clinical scenarios, three different model types were used. Six plastic models of each model type were fabricated from epoxy resin. Each model contained 2 bilaterally, palatally impacted canines, that were randomly embedded in the models, in the canine region. Impacted canines were exposed by either a traditional approach, or guided by dynamic navigation randomly assigned to the right and left side of the same model. Time to plan/prepare, drill, and sizes of the initial and final osteotomy to expose the impacted teeth were measured and compared for the two methods.

Results: Bilaterally, palatally impacted canines were exposed either with the freehand or with guided navigation approach in 18 models, a total of 36 sites evenly distributed. Average procedure times and volume measures are presented in Table 1. The time to prepare for the procedure was significantly longer for the guided navigation experiments (p <.0001). Preparation time was on average 10:07 for guided navigation and 3:19 for freehand. The time to locate the tooth was significantly different on the left side of the models with guided taking approximately 2 minutes longer than freehand (122.78s; p=.0423) but did not differ significantly on the right (16.78s longer for freehand; p=.9809). The time to finish the procedure did not differ significantly based on the method (p=0.8342) or the side of the model (p=.3441). The total time was significantly longer for the guided navigation (7:48; p<.0001). Figure 1 displays the average time for each portion of the procedure along with the total time by both side and method. Based on a volumetric assessment, the size of the initial osteotomy was significantly smaller for guided navigation on the right side of the models by an average of 7.13mm3 (adjusted p=.0097). Figure 2 displays the average entry volume by method and side of the jaw.The difference on the left side of the models was not significant (1.86mm3, p=.9933). The total volume removed did not differ significantly between the two methods (78.9 vs 77.4 mm3; p=.7793) or on the side of the model (79.1 vs 77.2 mm3, p=.7175). Figure 3 displays the average total volume removed by method and side of the jaw.

Conclusions: Within the limitations of this study, dynamic navigation methods require more time to prepare prior to initiation of surgery, as well as to locate the impacted canine on the left side of the palate, for a right handed operator. Initial access volume was significantly smaller with dynamic navigation on the right side, but the benefit was not seen on the opposite side. No significant differences were seen in the time to finalize the osteotomy or the final size. Dynamic navigation could add significant value to a surgeon in certain clinical presentations, such as proximity to vital structures and adjacent roots, despite the increased time for preparation.

Lead Author’s Contributions to the Research Project: The lead author was responsible for project design, data collection and composition of the abstract