ABSTRACT
This group of TMJ disorders are those without demonstrable joint pathology but marked symptoms. They comprise masticatory muscle dysfunction and disc interference disorders.
There have been many descriptions, classifications and theories about functional masticatory disorders. The determinants of normal occlusion, resting muscle fibre length, mandibular rest position and pattern of masticatory movements have all been extensively investigated. Activity of the masticatory system can be functional, adaptive or parafunctional.
