From the case:
Double disc sign - TMJ
{"current_user":null,"step_through_annotations":true,"access":{"can_edit":false,"can_download":true,"can_toggle_annotations":true,"can_feature":false,"can_examine_pipeline_reports":false,"can_pin":false},"extraPropsURL":"/studies/7208/annotated_viewer_json?lang=us"}
Both thickening of the inferior belly of the lateral pterygoid insertion (below) and an anteriorly dislocated disc are present. The two structures, parallel each other is referred to as the double-disc sign.