This book studies the biomechanics and functional anatomy of temporomandibular joint and disorders related to it. Temporomandibular disorders (TMD) is a collective term that embraces a number of clinical conditions that involve the masticatory musculature and/or temporomandibular (TM) joints and associated structures. Various clinical conditions are characterized by pain in the preauricular area TM joint or muscles of mastication; limitation or deviation in mandibular range of motion; and TM joint sounds (clicking popping crepitus) during mandibular function. As with other musculoskeletal disorders pain during function and/or at rest is the primary reason patients seek treatment and reduction in pain is generally the primary goal of therapy.