Éléments de diagnostic des algies de l'appareil manducateur

Painful temporomandibular disorders affecting the masticatory muscles and the temporomandibular joint are common and represent the most frequent cause of orofacial pain after dental pain. Given the complexity of the trigeminal innervation, at the origin of many referred pain, these disorders sometimes lead to a problem of differential diagnosis, especially when they are located in the auricular or pre-auricular region. Also, the differential diagnosis between the pain of muscular and articular origin is not always obvious, in particular because of the existence of certain common clinical signs such as a mouth opening limitation and a pain caused by chewing. The objective of this article is to describe the characteristics of the main painful symptoms of temporomandibular disorders represented by myalgia (acute or chronic) affecting the masticatory muscles and arthralgia (TMJ) that occur in four main clinical situations: capsulitis, retrodiscite, acute disc displacement without reduction and arthritis. The pain history and the patient examination are essential for the diagnosis. The TMJ imaging (MRI, scanner) is often unnecessary and restricted to specific situations, not allowing to make a reliable diagnosis.