Radiographic evaluation of degenerative findings in the temporomandibular joint using CBCT: a prevalence-based study

Degenerative changes of the temporomandibular joint (TMJ) are common radiological findings and may reflect aging, functional adaptation, or pathological remodeling. Cone-beam computed tomography (CBCT) provides high-resolution visualization of osseous structures and is widely used for detailed evaluation of TMJ bony alterations. The present study aimed to evaluate the prevalence of degenerative changes and anatomical variations of the TMJ using CBCT and to investigate their associations with age, gender, and with each other. In this retrospective study, 1636 condyles were analyzed in CBCT images of 818 patients (214 men, 604 women) who obtained TMJ imaging at two university centers between 2022 and 2025. Two experienced radiologists independently evaluated the CBCT images. The parameters assessed included flattening, erosion, osteophyte, sclerosis, subchondral cyst, glenoid fossa thickening, joint space narrowing, bifid condyle, loose joint body, and condyle-fossa position. Statistical analysis was performed using SPSS version 22.0, with a significance level set at p < 0.05. At least one degenerative change was detected in 78.6% of the condyles. The most common findings were flattening (31.4%), erosion (28.9%), and osteophyte formation (27.2%). Erosion, osteophyte, subchondral cyst and bifid condyle were significantly more prevalent in females (p < 0.05). The frequency of osteophytes, subchondral cysts, and posterior condyle position increased with age. Osteophyte formation showed significant associations with other degenerative changes (p < 0.001). Degenerative changes in the TMJ frequently coexist and are influenced by demographic factors such as age and gender. CBCT is an effective and reliable imaging modality for detailed evaluation of osseous changes in the temporomandibular joint. From a clinical perspective, the presented prevalence data provide a reference framework for radiologists and clinicians when interpreting CBCT findings of the temporomandibular joint. This framework may support more informed reporting and help avoid overdiagnosis when radiological findings are not accompanied by relevant clinical symptoms.