CBCT image based radiomic analysis for condylar resorption after orthognathic surgery.

OBJECTIVES: To select and discover features which are highly correlated with condylar resorption (CR) after orthognathic surgery (OS) by a new method. MATERIALS AND METHODS: The cone beam computed tomography (CBCT) images were collected from orthognathic patients taken at T1(baseline time point) and T2(within 3-36 months postoperatively). The subjects were divided into the CR group and the control group by using a 2-level scale after registering T1 and T2 images. The condyles were segmented by MVEL-Net network model and were analyzed by Pyradiomics. The D-value equaled to the absolute difference-value (D-value) between the feature values of T1 and T2. The correlation between features with statistically significant differences in T1 and D-values would be analyzed to find the specific features related to CR after OS. RESULTS: A total of 145 subjects were included (27 males and 118 females), which had 44 subjects in the CR group, 101 subjects in the control group. For all samples, a total of 82 features were extracted (F(1)), which were with statistical differences at T1 time point between CR and control groups. By using the D-value, the number of features was reduced to 32 features (F(d)). Among F(d), only 3 were not included in F(1). CONCLUSIONS: The D-value was proposed for selecting specific features of CR after OS and it can be observed that the D-value serves the purpose of feature specification compared to T1 values. By using the D-values, several features were found to change significantly during the process of CR after OS. CLINICAL RELEVANCE: The features selected by D-value can be used for the establishment of a prediction model for CR after OS.