RESUMO
The understanding of the causes of temporomandibular joint pain and dysfunction has evolved over 50 years. Historically, the term internal derangement has been used to describe the abnormal relationship between the articular disc, condyle, and glenoid fossa, which was thought to correlate with patient symptoms. It is now known that the pathophysiology of intra-articular pain and dysfunction (IPD) involves synovitis, capsular impingement, symptomatic disc displacement, or a combination of these. Symptomatic disc displacement should only be considered to be a potential source of IPD after synovitis and capsular impingement have been treated. This philosophy provides the opportunity for most patients with IPD to be initially treated nonsurgically or with minimally invasive procedures such as arthrocentesis or arthroscopy.