Temporomandibular diseases and disorders, commonly referred to as "TMJ", represent a family of complex and poorly understood health problems manifested by pain in and around the jaw and associated muscles, and limitations in the ability to make the normal movements of speech, facial expression, eating, chewing, and swallowing. One of the critical needs in this field is to develop scientifically validated guidelines for their diagnosis. In "Advancing Diagnostic Approaches for TMJ Disorders", scientists from different disciplines collaborate to provide an understanding of the needs and challenges currently faced in the diagnosis of temporomandibular diseases and disorders. Papers in this volume assess current methods and explore new ways to define the TMJ vulnerable population through the utilization of new and emerging technologies provided through bioengineering, bioimaging, and computational biology.