Abstract
Objective: To investigate the morphological characteristics of the temporomandibular joint (TMJ) capsule-condyle distance using ultrasound imaging in individuals with different Angle’s occlusal classifications.
Methods: Ultrasound imaging was performed in both transverse and longitudinal planes, capturing measurements with the mouth closed and open. Six specific joint space distances were recorded: LLC, LLO, LTC, LTO, ATC, and ATO.
Results: All six joint space measurements showed significant deviation from a normal distribution. Median values ranged from 0.9 mm to 1.1 mm, with interquartile ranges between 0.5 mm and 0.8 mm (p < 0.05). Venn diagram analysis demonstrated strong co-occurrence of altered joint spaces in both mouth positions. Pearson correlations revealed significant positive relationships between measurements, notably between ATC and LTC (r = 0.62) and between LLO and LTO (r = 0.52). Moderate correlations were also seen between open- and closed-mouth measurements. Occlusal classification and laterality had no significant effects on joint space (η² ≈ 2.92–2.95, P > 0.05).
Conclusion: Ultrasound assessments showed that TMJ capsule–condyle distances were not significantly affected by Angle’s classification. This may reflect the limitation of ultrasound in detecting subtle morphological variations, suggesting a need for higher-resolution imaging in future studies.