Comparing the accuracy and precision of digital model transfer methods used in virtual orthognathic planning

Abstract

The hard and soft tissues of the head and neck, dentition, and temporomandibular joint are the determining elements in orthognathic surgery planning. The accuracy and precision of the relationship between the jaws at the beginning of treatment and their final position depend on an accurate dentition record. The aim of this study was to determine the simplest and most feasible virtual dental model transfer method for three-dimensional orthognathic planning according to clinical applicability, technical difficulty, effective costs, accuracy, and precision. A total of ten spherical porcelain markers were placed in plaster models of the maxilla and mandible of a patient. The models were scanned using an intraoral optical scanner, an extraoral digital model scanner, and cone-beam computerized tomography. To evaluate reliability, each measurement was repeated 10 times at 1-week intervals and the distances between points were measured horizontally and vertically. The findings obtained in the study were evaluated statistically using IBM SPSS Statistics 2.2 program. Measurements obtained with the extraoral model scanner did not differ from the digital caliper method (P > 0.05), while there were significant differences between the digital caliper and the other methods (intraoral 3D scanner P = 0.000; CBCT P = 0.001). Although all of the measurements showed high consistency among all methods, the most accurate results were obtained with the extraoral digital model scanner. (r = 0.99, P = 0.01, P < 0.05).