THE ROLE OF MAGNETIC RESONANCE RESEARCH IN THE TREATMENT OF DYSFUNCTION OF THE TEMPOROMANDIBULAR JOINT
Authors: Novikov V.M. , Korostashova M.A. , Dodatko V.I. , Svyryda O.S. , Yushchenko Ya.O. 
Published: June 2021

The main criterion for diagnosis of dysfunctional conditions of the temporomandibular joint is the visualization of the intra-articular cartilaginous disc. The method of diagnosis, that the most perfectly determines the disorders in the temporomandibular joint, particular the displacement of the menisci, is magnetic resonance imaging. So, the aim of the work was to determine the amplitude of anterior displacements of the menisci in patients suffering from dysfunction of the temporomandibular joint using magnetic resonance imaging.
In 20 patients, who underwent magnetic resonance imaging, different amplitudes of the anterior displacements of the meniscus were determined. Patients were divided into groups. The first group included 6 patients who were diagnosed by MRI the anterior displacement of the disc to the center of the articular head. The second group included 4 patients who had anterior displacement of the disc to the center of the articular head by 2/3 of its own length. Ten patients of the third group had a displacement of the meniscus to the center of the articular head by 1/2 of its own length. For the future treatment of TMJ dysfunction, the distance of the pathological displacement of the meniscus determines the degree of occlusion. All patients were prescribed a Michigan-splint occlusal splint in combination with a sling-like head cap at night. The results of the selected treatment were interpreted after 3-6 months.
A series of magnetic resonance imaging has described the articular fissures of the temporomandibular joint, articular discs (their shape in frontal projection and on parasagittal sections), posterior ligaments, and lateral pterygoid muscles. Each of the joints was carefully examined in the case when the mouth is closed and open. During the MRI description, the shape of the joint heads and their possible pathological changes were determined. In the position of the closed or open mouth, the positions of each of the discs and their poles relatively to the articular head in centimeters were compared, and the movement of the menisci was described. The sizes of disks of the closed and open mouth were defined. The study protocol also reported the shape and amplitude of the movements of the articular heads.
Treatment was planned according to the selected protocol. For the first group of patients diagnosed with anterior meniscus dislocation, treatment was planned by separating the occlusion to the relatively physiological rest of the mandible (2 - 4 mm). The patients of the second group, in which anterior displacements of the disc relatively to the articular head by 2/3, were treated with detachment of the occlusion to contact with the cutting edge of the teeth of the upper and lower jaws. For the third patients’ group with diagnosed anterior displacement of the meniscus by 1/2, treatment was performed with a separation of the bite on 2 - 4 mm above the contact with the cutting edges of the front teeth. The main criterion for recovery is the complete disappearance of symptoms of dysfunction, even without the use of a splint.
At the first stage of treatment the task was the following: reconstruction of a myotatic reflex by means of the medical and diagnostic occlusal splint "Michigan-splint" completed with the main slingshot cap. Patients were monitored monthly. The main problems were the following: after a week of using the structure the patients complained of increased salivation, muscle pain and burning, headache, which disappeared after approximately 3 weeks. The main cause of such phenomena is the physiological rearrangement of the muscular reflex, which involves a certain tension in the muscles and irritation of the nerve endings in the muscles due to changes in the usual occlusion. During planned examination, the patients demonstrated supercontacts followed by cap correction. In 3 or 6 months of using the Michigan-splint occlusal splint, patients noted a significant improvement and they didn’t have any complaints. The main criterion for recovery is the complete disappearance of symptoms of dysfunction, even without the use of a splint. Therefore, the next stage of treatment depended on the anatomical and functional changes of TMJ and consolidation of therapeutic effect was been necessary.
Therefore, the use of magnetic resonance imaging of the temporomandibular joint to determine the amplitude of the displacements of the discs, ensures the effectiveness of the selected treatment.
Prospects for further research include improvement of the MRI protocol and its correlation with definite symptoms, the distance of the vertical separation of occlusal surfaces, and the introduction of the protocol into practical health care.