Temporomandibular Joint Characters In Class II Malocclusion Patients

This study uses CBCT to investigate TMJ morphology and compensatory mechanisms in Class II malocclusion, aiming to reveal unique anatomical features and guide clinical treatment strategies. This research selected 120 patients from an orthodontic department and divided them into four groups: Early mixed dentition Class II (T1, n=20), adolescent permanent dentition Class II (T2, n=20), adult Class II (T3, n=20), and early mixed dentition Class I (T0, n=20). Data Acquisition: CBCT scans were performed using a NewtomVGi device. Measurements included condylar dimensions, angles, joint spaces, and glenoid fossa dimensions. All measurements were conducted by a single researcher using NNT Viewer 5.3 software, repeated three times for accuracy. Compared to Class I patients (T0), Class II patients (T1) showed smaller condylar width, shallower glenoid fossa, and reduced coronal condylar angle, but larger sagittal condylar angle and lateral joint space (P<0.05). With age, condylar volume increased, the glenoid fossa deepened, and the articular eminence inclined more, indicating a compensatory trend in TMJ adapting to maxillomandibular discrepancies. This research findings reveal distinct morphological characteristics in TMJs of Class II malocclusion patients, including reduced condylar width, shallower glenoid fossa, flatter articular eminence, and anteriorly positioned condyles. These features differ significantly from Class I patients and reflect functional adaptations. TMJ structures mature with age, evidenced by increased condylar volume and deeper glenoid fossa, highlighting the role of compensatory mechanisms. These insights provide a basis for personalized orthodontic treatment strategies.