 Welcome to MRIOnline's tutorial on the temporal mandibular joint, the off-forgotten joint. Approximately 10 million individuals, most of them women in the United States, are affected by temporal mandibular joint abnormalities. This data comes from the National Institute of Health and other dental data. The prevalence of female involvement reported as 5 to 1 or 10 to 1 is more likely 20 to 1 and is seen more frequently in individuals between 20 and 40 years of age. Bilateral abnormalities are common, it's about 60 percent bilateral, 40 percent unilateral. Wetson and colleagues reported that clicking or limitation of motion was the presenting symptom in about 39 to 40 percent of the general population. The overall prevalence of TMJ derangement in the general population is close to 25 and maybe even as much as 30 percent or a third. Certainly it can be that high in women. MRI is clearly the modality of choice for imaging for a number of reasons. It shows all the soft tissues. It does a good job, although not as good a job as CT at showing the articular surfaces, a far better job at showing the meniscus or disc, the retro meniscal tissues, the muscles, the synovium, et cetera. Despite the high prevalence of this disorder, only 5 to 10 percent with symptoms require some interventional treatment. Most of them can get by with non-aggressive, non-invasive treatments including bite plates and physical therapy types of training. So let's get started and talk about the anatomy on MRI which is paired with this introduction to MRI of the temporal mandibular joint.