What characterizes left side anterior disc displacement without reduction?

• A. Excessive range of motion and deviation to the unaffected side
• B. Restricted range of motion and deviation towards the affected side
• C. Normal range of motion
• D. Pain during every mouth opening

Answer: (B)

Left side anterior disc displacement without reduction typically presents with a restricted range of motion and deviation towards the affected side. This condition occurs when the articular disc in the temporomandibular joint (TMJ) is displaced anteriorly and cannot return to its normal position during mouth opening.

As a result, the motion of the jaw becomes restricted because of the altered mechanics of the joint. The deviation towards the affected side happens because the mandible moves in a manner that compensates for the anteriorly displaced disc, leading to an asymmetrical motion. This is due to the fact that when a restriction is present on one side, the jaw will tend to move towards that limited side during functional activities such as opening the mouth.

Additionally, pain may or may not occur with this type of displacement, but pain during every mouth opening is not a universal characteristic. While some patients might experience pain, it is not definitive for this condition. Thus, the emphasis is on the mechanical restriction and the resulting deviation to the affected side, making the identification of this situation key for diagnosis and appropriate management in clinical practice.