Cone-Beam CT-Based Analysis of Temporomandibular Joint Osseous Changes in Orthognathic Surgery Patients: A...

Background/Objectives: The aim of this study is to evaluate pretreatment osseous changes in the temporomandibular joint (TMJ) in orthognathic surgery patients using cone-beam computed tomography (CBCT) and to determine the distribution of the findings according to sagittal skeletal malocclusion groups. Methods: CBCT images of 103 patients (206 condyles) were retrospectively analyzed. Patients were classified as Class I, II, and III based on ANB angles. Condylar morphology was assessed for flattening, sclerosis, erosion, osteophyte formation, and subchondral bone cysts. All evaluations were performed by a single investigator (κ = 0.87). Group differences were analyzed using the chi-square test with Bonferroni correction (p < 0.05). Results: The most frequent alteration was flattening (29.6%), followed by sclerosis (11.2%), erosion (10.7%), osteophyte formation (8.3%), and subchondral bone cysts (4.4%). No significant sex-related differences were found (p > 0.05). A significant difference was observed only in sclerosis (p = 0.049), which was more prevalent in Class I than Class III. Flattening predominated in all groups, while erosion and osteophytes were more common in Class II, and sclerosis was more frequent in Class I. Conclusions: This study demonstrated that condylar flattening was the most common morphological alteration in orthognathic patients across all skeletal malocclusion groups. The higher prevalence of sclerosis in Class I compared with Class III suggests that mandibular positioning may influence adaptive and degenerative remodeling processes of the TMJ. This study emphasizes the importance of CBCT evaluation for detecting osseous changes in TMJ before orthognathic surgery and demonstrates that pre-existing alterations may impact surgical stability and postoperative functional outcomes.