This study aimed to assess the precision of 3D-printed orthognathic surgical splints (OSS) with different dental model offsets and explore the optimal offsets of OSS.Methods
Ten resin models that met the standard of normal occlusion were selected, and the digital models were obtained by using an optical scanner. The research models were made by using a 3D photosensitive resin printer, and then the original digital models were obtained. Digital OSS with different offsets (0.00, 0.05, 0.10, 0.15, 0.20, and 0.25 mm groups) was designed for each model, and physical OSS was fabricated by 3D printing. The upper and lower dentition of each resin model was reoccluded in OSS with different offsets, and the deviation of the actual occlusion from the original occlusion in six dimensions of horizontal, sagittal, vertical, pitch, roll, and yaw was evaluated.Results
1) The actual occlusion obtained by OSS without offsets (0.00 mm group) had deviation in six dimensions, and the deviation in vertical (1.044±0.181 mm) and pitch (1.738°±0.772°) dimensions was the largest. 2) In sagittal, vertical, pitch, and roll dimensions, the mean value of actual occlusal deviation gradually decreases with the increase of offsets. In the vertical and pitch dimensions, the actual occlusal deviation of the 0.15 mm group was significantly less than that of the 0.00, 0.05, and 0.10 mm groups (P<0.01), but no significant difference was found between the 0.20 mm and 0.25 mm groups (P>0.05). In addition, no significant difference in sagittal and roll dimensions was found among the groups (P>0.05). 3) In the horizontal and yaw dimensions, within the range of 0.00-0.20 mm, the mean value of actual occlusal deviation gradually decreased with the increase of offsets (P>0.05). However, the actual occlusal deviation of the 0.25 mm group was larger than that of the 0.20 mm group (P>0.05).Conclusion
3D printed OSS with offsets can reduce the deviation of the actual occlusion. Among the parameters, 0.15 mm is the suitable option for generating OSS.