The normal temporomandibular joint: MR and arthrographic correlation

Area of Science:

• Radiology
• Orthopedics
• Anatomy

Background:

• Temporomandibular joint (TMJ) disorders are common.
• Accurate diagnosis relies on imaging modalities like MRI and arthrography.
• Understanding normal anatomical variations is crucial for interpreting joint imaging.

Purpose of the Study:

• To correlate magnetic resonance (MR) imaging findings of normal temporomandibular joint (TMJ) articular menisci with arthrographic appearances.
• To determine if specific meniscal configurations on MR imaging can explain apparent abnormalities seen on arthrography.

Main Methods:

• MR images of 28 normal TMJ specimens were acquired.
• These MR images were correlated with corresponding arthrograms of the same joints.
• Specific attention was paid to the configuration and thickness of the anterior band of the articular meniscus.

Main Results:

• A spectrum of normal articular meniscal configurations was observed on MR images.
• The anterior band varied from thin with a flat inferior margin to thick with a bulbous, convex inferior margin.
• Meniscal morphology on MR directly correlated with the appearance of the anterior recess on arthrography; a thick anterior band corresponded to a concave anterior recess, and a thin band to a flat recess.

Conclusions:

• The appearance of a concave anterior recess on static arthrograms does not necessarily indicate a displaced meniscus.
• Normal variations in the anterior band of the TMJ meniscus can mimic pathology on arthrography.
• MR imaging is valuable for differentiating normal meniscal variations from actual displacement.