Comparison of the Accuracy of Maxillary Repositioning Between Using Splints and Templates in 2-Jaw Orthognathic Surgery

Abstract

Printed cutting and repositioning templates could bring superior accuracy when transferring a maxillary plan to the operating room compared to a wafer-based method. However, the effect of these methods in different types of cases is inconclusive. The objective of the study was to compare the accuracy when using printed occlusal splints versus templates in simple and complicated cases. A retrospective cohort study design was used. Complicated cases were defined as cases involving impaction movement of more than 2mm, occlusal plane canting of more than 3°, or midline discrepancies of more than 2.5mm. Other cases were simple cases. Enrolled patients were randomly allocated into the digital occlusal splint (DOS) cohort and the digital templates (DT) cohort. The outcome variable was surgical accuracy, defined as the average deviation between the planned and postsurgical locations of bilateral maxillary central incisors, canines, first premolars, and first molars. Predictor variables were 1) operative complexity, simple versus complicated; and 2) technique for positioning the maxilla, DOS versus DT. Covariates were age and planned surgical movement. Two-way analysis of variance was used. Seventy patients were included in this study. Thirty-three were in the DOS cohort, and 37 in the DT cohort. The average deviation was significantly smaller in the complicated cases in the DT cohort (1.37mm; 95% confidence interval, 1.08-1.66mm) than that in the DOS cohort (2.47mm; 95% confidence interval, 1.92-3.02mm) (P=.002). The deviations in anteroposterior direction of complicated cases in the DT cohort were smaller than the corresponding values of the DOS cohort (P=.035). There is no significant difference between the deviation values of simple and complicated cases using templates (P=.116). These results indicate that in complicated cases, printed guiding templates exhibit better accuracy for repositioning the maxilla than printed occlusal splints, and the effect of templates in different cases proved to be stable.