Temporomandibular Joint Intra-articular Pressure Regulation: a Large-scale Multicenter Prospective Study

Objectives: The temporomandibular joint (TMJ) intra-articular pressure (IAP) is the pressure of the synovial fluid in the upper compartment of the joint. The quantity and fluctuation principles of IAP can be used to explain the pathogenic factors and pathogenesis of temporomandibular disorders (TMDs). The current study explore the significance of new classification based on IAP in TMD treatment, analyze the mechanism of pressure regulation, propose individual therapy for patients with anterior disc displacement without reduction (ADDwoR), and develop and promote the application of pressure regulating therapy (PRT) in TMDs.
Methods: Since 2009, we have carried on a large-scale multicenter prospective clinical study based on the IAP measurement equipment invented by ourselves. 800 cases with TMDs were included in the experiment which have been measured the IAP in the upper compartment of TMJ. Furthermore, 231 ADDwoR cases have been classified according to the character of IAP. Combining the clinical examination, radiology data, mandibular movement records and electromyogram, an individual computational fluid dynamics model was constructed and an individual therapy strategy was proposed. IAP was measured in all patients in the follow-up, due to its role as the key index in joint disease therapy.
Results: According to the IAP measurement, ADDwoR can be classified into high pressure type, low pressure type and the reverse pressure type (Table I). Patients were treated with PRT. The high pressure type of ADDwoR was treated with decompression, the low pressure type with pressurization, and the reverse pressure type with treatment according to the specific situation. Individualized treatment plan obtained better prognosis.
Conclusions: Studying the intra-articular fluid dynamics helps understand the symptoms and signs, and aids in developing successful treatment strategies. The interruption of synovial circulation pattern plays a crucial role in TMD pathogenesis. Individual therapy combining TMJ anatomical characteristics and pathologic features contributes to the long-term therapeutic effect.