Clinical and Pantronic Study of Temporomandibular Joint Disorders

An analysis of the condylar paths and mandibular movements with DENAR PANTRONIC (Electric computerized pantograph) in one control subject and 11patients with temporomandibular joint (TMJ) disorders is described with presentation of three cases. The patients consisting of three males and eight females were selected based on their histories, muscles examination (Krough-Poulen's) and occlusal findings of the study casts on the articulator. The analysed items included (1) age (2) sex (3) clicking (4) muscle diagnosis (5) condylar shape (6) CR (7) side-shift (8) Fisher's angle (9) diagnosis of occlusal interference or disk derangement (10) deviation or restriction of rotating condyle and mandibular movement. In the control subject, mandibular movements and condylar paths were reproducible and coordination with the mastication muscles were observed. All volumes studied by PANTRONIC were within the range of the standard deviation. In case 3, PANTRONIC study of the mandibular movements was not possible because of the spasms of the mastication muscles on her initial visit. After two weeks of occlusal adjustment, multiple centric relation was still noted but her mandibular movements became coordinated with the mastication muscles. Despite the lack of reproducibility of condylar path, ISS and PSS returned to normal volumes. Fisher's angle was nine degrees which was still out of ISD. Smooth movement of the condyles riding on the disks was recovered. Occlusal interference arthrosis was the diagnosis based on the above findings. Case 1 showed Z jump on the path of the protrusive mandibular movement and poor reproducibility of the condylar movements in spite of the lateral mandibular movements cooperating with the mastication muscles. ISS was over 1mm and the rotating condylar paths showed a curved line on the posterior holizontal record. The both condyles were deviated anterioly and on the frontal view downward displacement of the right condyle were observed. Under the influence of clicking, the sagittal condylar path showed a partial loss at the starting point of the protrusive mandibular movement. There was a large difference of Fisher's angle between the right and left sides and the inclination of the right sagittal condylar angle was over 50 degrees. Although the left condyle took a smooth movement with the disk, the right condyle showed a straight tracing along the condylar path, the findings indicated complete anterior dislocation of the disk on the right side. The results of analyzing of 11 patients are sammerised as follows. (1) Patients with T M J disorders show low responcibility in mandibular and condylar movements. (2) Z jump and double side-shift are recognized on the protrusive mandibular and holizontal codylar tracings. (3) They have multiple centric relation. (4) ISS is over 0.3 mm. (5) Disk derangements are characterized by sharpening and unclearness of Fisher's angle and a straight tracing on the sagittal condylar path. PRI score is also increased. (6) After treatment, reproducibility of the mandibular movement is recovered. (7) Past treatment, condylar paths (inclination sagittal condylar path, PSS, ISS) Shown by PANTRONIC are used to reconstruct occlusion based on the principle of overcompensation