Temporomandibular joint condylar/fossa positional changes after Herbst and Xbow treatments in adolescents assessed through cone-beam computed tomography imaging: A randomized controlled trial

This 3-arm parallel randomized clinical trial evaluated the 3-dimensional positional changes (anteroposterior, vertical, and mediolateral) in the condyle and glenoid fossa using different Class II fixed mandibular positioners/appliances (Herbst and Xbow) compared to a control group. A total of 54 patients were included and randomly assigned to 1 of 3 groups (Herbst, Xbow, and control) and followed up for an average of 12.4 months. Two cone-beam computed tomography images corresponding to pretreatment and posttreatment were taken for each patient. The mandibular condyle and glenoid fossa position relative to the reference planes were assessed using Avizo software (Thermo Fisher Science, Berlin, Germany) and landmark-to-plane distance calculation. Reliability was assessed using the intraclass correlation coefficient (ICC). Multivariate analysis of variance was conducted to determine the differences among the groups. Intrarater reliability displayed high reliability with an ICCx (ICC for x-axis measurements) of 0.99 (95% confidence interval, 0.98-1.00) and ICCy (ICC for y-axis measurements) and ICCZ (ICC for z-axis measurements) of 1.00 (95% confidence interval, 1.00-1.00) with P <0.0026. Regarding all dimensional positional changes (anteroposterior, mediolateral, and vertical), there was no significant difference in means of variations in the orthogonal distance of the condyle and glenoid fossa landmarks based on groups (P >0.05). Fixed Class II orthodontic appliances (Herbst and Xbow) did not show condyle or glenoid fossa position changes relative to the reference planes formed by the cranial base and facial landmarks or change in position of the condyle relative to the glenoid fossa compared to the control group. The study was registered with the International Standard Randomised Controlled Trial Number registry with registration No. ISRCTN57079737, retrospectively registered on October 21, 2022 (https://www.isrctn.com/ISRCTN57079737?q=ISRCTN57079737&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10). International Standard Randomised Controlled Trial No. ISRCTN57079737. This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors.