الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The most frequent cause of temporomandibular joint disorders is internal derangement. Internal derangement results from an abnormal relationship between the disc and articulating surfaces )glenoid fossa, mandibular condyle and articular eminence ( that interferes with smooth joint function.
Internal derangement is considered to be a progressive disorder. In initial stages the disc is usually displaced forward when the mouth is closed and return to normal position (recaptures) on mouth opening, anterior disc displacement with reduction. As the elastic fibers in the bilaminer zone become stretched and lose elasticity, the disc no longer recaptures with mouth opening, anterior disc displacement without reduction.
If the patient cannot achieve proper treatment, ID gets progressively worse with time, inflammation accompanied and osteoarthritic changes (abrasion of articular cartilage and underlying bone, flattening of articular surfaces and osteophyte formation) occur.
MR imaging has the advantage of providing detailed anatomic information involving the articulation and the surrounding structures and can be performed in closed & opened mouth positions.