Introducing a novice-friendly classification system for magnetic resonance imaging of the temporomandibular joint disc morphology

• Published in: Oral radiology Vol. 39; no. 1; pp. 143 - 152
• Main Authors: Zhang, Qinlanhui, Xiong, Xin, Gong, Yanji, Liu, Fang, Liu, Yang
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 2023; Springer Nature B.V
• Subjects: Classification; Classification systems; Dentistry; Diagnosis; Humans; Imaging; Joint Dislocations - diagnosis; Joint Dislocations - pathology; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Medicine; Morphology; Oral and Maxillofacial Surgery; Original Article; Radiology; Reproducibility of Results; Statistical analysis; Temporomandibular joint; Temporomandibular Joint Disc - diagnostic imaging; Temporomandibular Joint Disorders - diagnostic imaging; Temporomandibular Joint Disorders - pathology; Classification system; Temporomandibular joint; Temporomandibular disorders; Disc shape; Magnetic resonance imaging
• ISSN: 0911-6028; 1613-9674
• DOI: 10.1007/s11282-022-00615-0

Objective To introduce a new classification, aiming to correspond TMJ disc configuration with diagnosis, meanwhile reduce difficulty and subjectivity in TMJ MRI evaluation and training of TMD diagnosis for dental students. Methods 90 patients sought for TMD treatment were enrolled in the study, whose MRIs were used to establish the new classification. A total of 180 discs were evaluated using MRI for position (normal, DDWR or DDWoR) and classified by morphology according to previous (Murakami’s classification) and new classification respectively. 60 discs were selected and judged by two groups (2 TMJ specialists and 30 dental students) to assess the reliability and validity of the new classification. Questionnaires were acquired for all observers to assess the attitude toward two classification systems. Descriptive statistics, Spearman’s rank correlation coefficient, and intraclass correlation coefficient were performed. P  < 0.05 was considered statistically significant. Results In the new classification, Class 1 disc was significantly correlated with DDWR and Class 3 disc was significantly correlated with DDWoR. Interobserver reliability/consistency for observers between TMJ specialists was 0.867 when Murakami’s classification was applied and 0.948 when the new classification was applied. Interobserver ICC value for dental students was 0.656 when using Murakami’s classification, and 0.831 when using the new classification. The difference in attitude toward different classification systems was statistically significant. Conclusion A new classification of TMJ disc configuration is presented. The correlation between disc morphology and position revealed helps diagnosis and management. The new classification improves TMJ MRI interpreting accuracy and provides a better learning and using experience.