TMJ Disc Displacement Angle Analysis in MRI: A New Proposal

Aniket U Vaidya,Nivedita Chinam,Nigel Figueiredo,Manisha M Khorate

doi:10.13189/ojdom.2020.080201

Abstract

Objective: To evaluate the co relation of clinical symptoms and MRI findings of TMJ in symptomatic Temporomandibular Dysfunction (TMD) patients. Material and Method: MRI TMJ scan of 25 patients were evaluated. The subjects had clinical evidence of reciprocal TMJ clicking or restricted mouth opening. This study determined the variability of temporomandibular joint (TMJ) disk position in antero-posterior aspect of the joint using magnetic resonance imaging (MRI). Disk position was evaluated on MRI by measuring the angle formed by a line through the middle of the condyle and tangential to the posterior-most aspect of the disk. Joint effusion was checked using T2 weighted image sequence. Thickness of superior and inferior head of lateral pterygoid muscle was measured. These MRI findings were then correlated statistically to clinical findings. Results: Out of 50 TMJ's (25 patients); 40% had biconcave shape (no deformity), 16% cases showed lengthened disc, 12% cases showed a flattened disc, 12% cases showed thick posterior band. Varying degrees of disc displacement was associated with disc shape deformity. Increased thickness of Inferior head of lateral Pterygoid had statistically strong association with pain. Conclusion: A strong positive co relation was seen between the clinical and MRI findings in symptomatic TMD patients. Further using this, a new Disc Displacement angle measurement method and classification of disc shape was proposed for better disc evaluation.

Highlights

One of the most common problems affecting Temporomandibular Joint (TMJ) is internal derangement. [1] This includes the abnormal relationship of the articular disc to the mandibular condyle, the fossa, and the articular eminence
The prevalence of Temporomandibular Dysfunction (TMD) symptoms was found to be more in females compared to males with a ratio of 3.16:1 (Table 2)
Type of Disc Displacement: Association of pain was statistically significant with disc displacement without reduction

Summary

Introduction

One of the most common problems affecting Temporomandibular Joint (TMJ) is internal derangement. [1] This includes the abnormal relationship of the articular disc to the mandibular condyle, the fossa, and the articular eminence. [1] This includes the abnormal relationship of the articular disc to the mandibular condyle, the fossa, and the articular eminence. One of the most common problems affecting Temporomandibular Joint (TMJ) is internal derangement. These alterations have been referred to as disc derangement. [2] Anterior Disc Displacement with reduction (ADDR) and Anterior Disc Displacement without reduction (ADDWOR) are the major findings in TMJ internal derangement whereas Posterior Disc Displacement is less common.

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Discussion

Conclusion