[Temporomandibular joint, occlusion and bruxism]

Temporomandibular joint and dental occlusion are joined for better and worse. TMJ has its own weaknesses, sometimes indicated by bad functional habits and occlusal disorders. Occlusal analysis needs to be addressed simply and clearly. The term "malocclusion" is not reliable to build epidemiological studies, etiologic mechanisms or therapeutic advice on this "diagnosis". Understanding the impact of pathogenic malocclusion is not just about occlusal relationships that are more or less defective, it requires to locate them within the skeletal framework, the articular and behavioural context of the patient, and above all to assess their impact on the functions of the masticatory system. The TMJ-occlusion couple is often symbiotic, developing together in relation to its environment, compensating for its own shortcomings. However, a third partner may alter this relationship, such as bruxism, or more generally oral parafunctions, trauma or an interventionist practitioner.

[The contribution of standard radiographs in the evaluation of masticatory system dysfunction]

Conventional x-ray films (orthopantomogram, teleradiogram) visualize many signs of dysfunction of the manducatory apparatus (DAM). Progress in our knowledge of the pathophysiology of DAM has brought new light to these radiographic signs. The orthopantomogram allows an assessment of modifications in muscle insertion zones secondary to their dysfunction and, more difficulty, the articular remodeling of the TMJ, mainly of the mandibular condyle and the articular space. The lateral teleradiogram studied by architectural and structural analysis provides information on the biomechanical balance of the cranio-facial structures and, especially, on the position of the mandibular rami. These standard radiograms are indispensable in the differential diagnosis, useful in the etiological diagnosis and are preliminary examinations prior to using other imaging techniques (MRI, CT). Standard films are easily reproducible for post-therapy follow-up.