Discussion
condylar head and glenoid fossa
The skeletal and dental effect of Herbst appliance has been investigated mostly by the conventional cephalometric radiographic techniques. Using those techniques, the researchers usually suffer from difficulty in identifying some landmarks such condylar head and glenoid fossa. The 2-dimensional radiographic image is subjected to magnification, distortion, patient positioning errors, and obstruction of critical landmarks by overlapping anatomic structures. The 2-dimensional linear and angular cephalometric measurements provide limited information’s about the movements of the structures and do not explain the complex 3-dimensional process of dento-skeletal response to the treatment. Additionally, the inherent examiner bias in the registration and superimposition process if the examiners are not blinded brings to question of the accuracy concerning the 2D readings.CBCT was developed from computed tomography (CT) and adapted to the use in the maxillofacial region, it has lower operational costs, more compact equipment and radiation dosage is much lower when compared to spiral C.T which frequently used in the field of medical imaging. At the same time CBCT offers images with corrected magnification and almost without distortion, also identifying the land marks is much accurate because of the ability to visualize the structures and perform measurements in specific axial, coronal, and sagittal slices to evaluate a specific area of interest. The main disadvantage of the CBCT in the present study is lack of norm for the study population.Therefore, the bottom line of the present study was to investigate the changes after Herbst appliance treatment and relate them to the pubertal status of the skeletal Class II patients using CBCT. The pubertal status was determined with respect to the CVMS by Bacetti et al.