A disorder of the disk within the temporomandibular joint can result in jaw complaints.


A derangement disorder of the TMJ disk involves one or both of the following:

(1) displacement of the disk (usually anteriorly)

(2) deformation of the disk


Clinical features of an intra-articular joint disk derangement:

(1) synovitis

(2) pain

(3) clicking on movement (if the disk reduces)

(4) limitation in the range of motion.


Initially there may be intermittent locking of the joint. As the disease progresses the disk may not reduce and there may be a "closed lock" of the TMJ.


The derangement may be unilateral or bilateral. If the condition is unilateral then symptoms tend to be worse on the affected side. There may be deviation of the jaw towards the affected side during jaw opening and closing


The diagnosis may be suspected clinically with confirmation by MRI done with the mouth open and closed.


To read more or access our algorithms and calculators, please log in or register.