[Idiopathic facial pain--Part 1: Definition, classification and etiology].

The present paper introduces a new concept in the physiopathology and treatment of the called 'temporomandibular dysfunction'. This paper was divided into two parts, this first explaining its definition, aetiology and hypothesis of the idiopathic facial pain. The second part, will mention its treatment, prognosis and recommendations. Under this new view, this 'dysfunction' is part of the called Idiopathic Facial Pain. The idiopathic facial pain is didactically subdivided in (1) facial artromialgia, (2) atypical facial pain, (3) atypical odontalgia and (4) oral dysestesia. Occlusal factors are less important in its aetiology, and psychological and biochemical factors are more recognised. Correct diagnosis is essential, and a full history, including psychological and social aspects is very important. The present management is based on a working model developed in this department and in other world centres, and is revolutionising the clinical management of the patients with idiopathic facial pain.