the correct position of the joint spaces for infiltrative procedures, arthrocentesis, and viscosupplementation. This is due to the fact that US provides a dynamic and real-time location of the component of the joints, while providing adequate lubrication and washing, which can be confirmed by the joint space increase post-treatment. Management TMD can be difficult to manage, and since the disorder transcends the boundaries between several health-care disciplines – in particular, dentistry and neurology, the treatment may often involve multiple approaches and be multidisciplinary. Most who are involved in treating and researching TMD now agree that any treatment carried out should not permanently alter the jaw or teeth, and should be reversible. To avoid permanent change, over-the-counter or prescription pain medications may be prescribed. Psychosocial and behavioral interventions Given the important role that psychosocial factors appear to play in TMD, psychosocial interventions could be viewed to be central to management of the condition. There is a suggestion that treatment of factors that modulate pain sensitivity such as mood disorders, anxiety and fatigue, may be important in the treatment of TMD, which often tends to attempt to address the pain directly. Cognitive Behavioral Therapy (CBT) has been used in TMD and has been shown to be efficacious by meta analyses. Hypnosis is suggested by some to be appropriate for TMD. Studies have suggested that it may even be more beneficial than occlusal splint therapy, and has comparable effects to relaxation techniques. Relaxation techniques include progressive muscle relaxation, yoga, and meditation. It has been suggested that TMD involves increased sensitivity to external stimuli leading to an increased sympathetic ("fight or flight") response with cardiovascular and respiratory alterations. Relaxation techniques cause reduced sympathetic activity, including muscle relaxation and reducing sensitivity to external stimuli, and provoke a general sense of well-being and reduced anxiety. Devices Occlusal splints (also termed bite plates or intra-oral appliances) are often used by dentists to treat TMD. They are usually made of acrylic and can be hard or soft. They can be designed to fit onto the upper teeth or the lower teeth. They may cover all the teeth in one arch (full coverage splint) or only some (partial coverage splint). Splints are also termed according to their intended mechanism, such as the anterior positioning splint or the stabilization splint. Although occlusal splints are generally considered a reversible treatment, sometimes partial coverage splints lead to pathologic tooth migration (changes in