Biometric Evaluation of Intracapsular Structures of the Temporomandibular Joint Before and After Orthesis Installation

Objective:The objective of this study was to evaluate the biometric modifications to intracapsular structures that occur after installation of orthoses of modified “Planas” type, in patients with TMD, by means of MRI of the TMJ. Methods and Material:Twelve patients with diagnoses of TMD were selected and clinically examined. They underwent TMJ examination using MRI before and after installation of the modified “Planas” orthoses. The examinations were performed using Siemens Concerto equipment with a magnetic field of 0.2 T and gradient of 20 mT and the image acquisition in the sagittal plane with a Flash-3Dsequence, weighted in T1, with and without the orthosis, with the open and closed mouth. The following measurement reference points were established: upper condyle, upper glenoid and lower glenoid. From these points, the distances between the upper glenoid and upper condyle and between the lower glenoid and upper condyle for closed and open mouth were measured on both joints. Results:The mean value for the closed mouth without appliance was 0.34 cm, and with the orthosis installed, it was 0.56 cm (increase of 0.22 cm). The value for open mouth without appliance was 1.15 cm and this was also the value for open mouth with appliance.Conclusion:We concluded that installation of the modified “Planas” orthosis significantly increased the upper glenoid and upper condyle spaces and that the increase in these spaces presented a significant correlation with clinical improvement of the patients.