Measurement of Mandibular Condylar Height Based on Magnetic Resonance Imaging

The aim of this study was to find out the most appropriate method of measuring condylar height on temporomandibular joint (TMJ) magnetic resonance imaging (MRI). Traditional three-circle method, modified three-circle method and ramal plane (RP) method were used by 2 separate observers for the measurement of condylar height and long axis of condyle on TMJ MRI. Pearson correlation coefficient (PCCs), intra-class correlation coefficient (ICC), paired t test and Bland-Altman analysis were applied for the comparison of CH and long axis of condyle between 2 observers. Thirty-two patients' images were finally included in our study. Comparing the 3 methods, it was revealed that the RP method has the highest consistency among the observers, followed by the modified three-circle method, and the traditional three-circle method has the worst consistency. The RP method is preferred for measuring the condylar height on MRI. If mandible edge cannot be observed on MRI, the modified three-circle method is recommended.