Quantitative assessment of temporomandibular disc and ligament changes in temporomandibular joint disorder using magnetic resonance T2 mapping

Abstract

Objective

This study aims to quantitatively assess microstructural and biochemical changes in the articular disc and periarticular ligaments associated with temporomandibular joint disorder (TMD) using magnetic resonance T2 mapping, and examines the potential utility of this imaging modality in disease monitoring.

Methods

A prospective cohort study was conducted involving 127 patients diagnosed with TMD and 51 asymptomatic controls, recruited at the hospital between June 2023 and January 2024. All patients underwent magnetic resonance imaging of the temporomandibular joint, including T2 mapping sequences. Image interpretation was independently performed by two radiologists blinded to clinical data. Cases were categorized based on the presence and severity of anterior disc displacement and associated tissue injury. Regions of interest were manually delineated on pseudo-color T2 maps in both open- and closed-mouth positions to obtain T2 relaxation values of the articular disc and periarticular ligaments. Comparative and correlation analyses were conducted using appropriate statistical techniques.

Results

Among patients with TMD, T2 values in the posterior portion of the articular disc were significantly higher than those in the anterior segment (p < 0.01), a finding not observed in the control group. Although no significant difference in disc T2 values was noted between open- and closed-mouth positions within each group, periarticular ligament T2 values differed significantly between these positions (p < 0.05). Both disc and periarticular ligament T2 values were significantly elevated in the TMD group compared to controls (p < 0.05). In the closed-mouth position, T2 values of both disc and periarticular ligaments demonstrated a positive correlation with increasing grades of anterior disc displacement and severity of tissue injury (p < 0.01).

Conclusion

T2 relaxation values increased with the progression of anterior disc displacement and tissue injury during early to intermediate stages of TMD, followed by a decline in later stages. A positive correlation was identified between T2 values of the articular disc and periarticular ligaments. T2 mapping in both open- and closed-mouth positions provided quantitative insight into structural changes of temporomandibular joint components and may serve as a valuable imaging biomarker for assessing tissue integrity and monitoring disease progression in TMD.