Abstract

Temporomandibular disorders (TMD) is frequently accompanied with malocclusion in orthodontic patients.  Approximately 20% of the patients with malocclusion arrive at our orthodontic clinic also affected by TMD.  Temporomandibular joint osteoarthritis (TMJ-OA) is characterized with degenerative joint changes such as deterioration and abrasion of articular cartilage, and occurrence of thickening and remodeling of the underlying bone.  Severe mandibular condylar resorption causes retrusion and deviation of the mandible, leading to the onset and progress of malocclusions such as skeletal open bite and mandibular deviation.

Although the detailed mechanism of TMD pathology remains unclear, inflammation induced by excessive mechanical stimuli in synovial membrane and condylar cartilage has been believed to play a crucial role in the incidence and progress of severe TMD accompanied by mandibular condylar resorption such as OA.  Recently, details of the mechanism by which proinflammatory response is induced through mechanoreceptors that receive an excessive mechanical load has been clarified.

In our department, all malocclusion patients with TMD diagnosed by initial clinical examination such as interview and palpation have TMJ-MRI examination before initiation of orthodontic treatment.  In case mandibular condylar deformity is detected by TMJ-MRI, observation period will be set, and orthodontic treatment is not initiated unless the calming down of the condylar resorption is confirmed by TMJ-MRI.  OA often progress relatively well, but idiopathic severe mandibular condylar resorption (ICR) is occasionally observed.  ICRis a pathology of the TMJ that is characterized by condylar deformation leading to idiopathic and progressive loss of condylar height.  Among the pathological conditions with mandibular resorption, ICR is diagnosed when the possibility of other diseases is excluded. 

  We have studied about pathogenic mechanism of TMD especially about condylar resorption to establish safe and reliable orthodontic treatment procedure for patients with malocclusion accompanied by TMD.  In this presentation, clinical data with several orthodontic cases for the past 30 years in our department.

Friday, 20 September 2024 - SESSION 1

ULUWATU (Room 2)