Dysfonctionnement de l’appareil manducateur

Abstract

Contact loss between the articular disc and the TMJ mandibular condyle, and the excessive stress on lateral pterygoid muscles can lead to temporo-mandibular dysfunction (TMD) in roughly 5% of people (twice more often in females). The TMD syndrome is a mix of pain and cliking arising from temporo-mandibular joint, sometimes associated with otalgia or tinnitus, and regional hypersensitivity, with myo-fascial pain of neighbouring muscles (masseter, temporalis, and sometimes sternocleidomastoid, scalenus, trapezus). Main symptoms are TM pain, often combined with cervicalgia and temporal and occipital headaches. Tinnitus and otalgia can also be found and are suggestive of the diagnosis when they occur during mouth opening. Pain in the throat and the face can also be noticed. A tenderness of the temporo-mandibular joint, an audible “click”, and an asymmetrical opening of the mouth, reduced to less than three fingers, are main findings. Several underlying disorders must be searched for: (1) malocclusion, sometimes induced by orthodontics treatments; (2) inappropriate dental prosthesis; (3) maxillo-mandibular dysmorphosis; (4) abnormal deglutition with tongue interposition during the 2500 oral stages of swallowing, so that speech therapist advice can be welcome; (5) cervical scoliosis and asymmetrical hearing or sight can worsen myofascial syndromes; (6) stress and fibromyalgia can coexist but are not the main source of TMD. Occlusal treatment, physiotherapy, cognitive-behavorial treatment seem the most useful treatments of this frustrating disorder, soft occlusal splint therapy being little effective.