Nihon Ago Kansetsu Gakkai Zasshi最新文献

We have been studying applicational arthroscopic surgery for temporomandibular joint diseases. Reported below is a newly designed system of diagnostic/operating arthroscopy. This prototype has an external diameter of 1.7 mm. The angle of vision is 60 degrees in air and 45 degrees in water. The effective length with the outer cannula set on is either 90 mm or 50 mm. The most important achievement of this device is that it enables the usage of two types of different sized outer cannula in the same arthroscope: a round single-channel sheath (external diameter 2.0 mm) and an oval double-channel sheath (3.8 X 2.0). The single-channel sheath can easily be replaced with the double-channel sheath by using internal and external guiding needles. This device can be used not only for diagnostic arthroscopy but also for arthroscopic surgery. In particular, it has a hole for surgical device insertion which enables parallel insertion of device. This makes it easy to always observe the advancing edge of surgical device and the manipulation can therefore be greatly improved.

TMJ sounds are very important for diagnosing the state of TMJ and for evaluation of the effect of treatment. We made a report on a recording system of TMJ sounds and mandibular movement which objectively can evaluate the relationship between TMJ sounds and mandibular movement. This time we recorded and analyzed the TMJ sounds and mandibular movement under following condition. 1. Opening and closing the mandibular on some regulated velocity. 2. Opening and closing the mandibular after clenching. Conclusion 1. In case of changing habitual opening velocity, there were significantly different position of clicking in the most of TMJ disorders patients. Especially with the increasing of the velocity, the position of closing clicking tended to come near the closed condyle position. 2. The amplitude of clicking sound increased very much at the time of opening stage after clenching on the non clicking side.

Patients with TMJ dysfunction often suffer from TMJ noise. However, determining the side at which the noise occurs is not always easy in auscultation or when picking up the noise electrically, because the sound is carried across the bony structure and picked up on both sides. To solve this problem, we utilized a three-directional accelerometer, measuring the sound on both sides in the hope that a difference in measurements would identify the side of the noise. We discovered that time difference between the acceleration peaks for the side originating the sound was shorter than that of the other side. Our report also contains a few observations on the result of this study on patients with plural TMJ noises occurring during one movement of the mandible.

This clinical report presents orthodontic applications of double contrast arthrotomography and arthroscopy of the temporomandibular joint. We examined a case of mandibular shift with stomatognathic dysfunction using these techniques, and found medial displacement of the articular disk. Generally, displacement of the articular disk is examined only from sagittal section. However, this case indicates that frontal section of double contrast arthrotomography is necessary for the three dimensional understanding of the TMJ. Mandibular position with disk reduction was obtained by double contrast arthrogram, and medial displacement of the disk and malocclusion were treated by dynamic positioner. It is suggested that orthodontic treatment is an effective method both for treatment of internal derangement of the TMJ and also for the final reconstruction of occlusion.

The fibrous connection of the discal attachment to the condyle and to the other structures around the disk was investigated histologically in order to reconfirm what Rees calls the bilaminar zone. Eleven TMJs were taken from fresh cadavers. Sections, obtained from six materials with condyle protruded, were observed. The Results were as follows: Most of the collagen fibers composing the articular disk attached to the area from the medial and lateral pole to the corner region of the posterior aspect of the condyle. But these fibers were not recognized on the posterior aspect of the condyle. A few of the fiber bundles composing the supra-lateral part of the disk were linked with the fibers of the periosteum of the lateral end of the articular tubercle. The fibers of the superficial layer of the posterior band linked with the fibers beneath the synovial membrane of the retrodiscal area, but these fibers were not observed to connect the disk with the posterior wall of the fossa. At the medial end of the disk, the elastin rich fibers originating from the petrotympanic fissure attached to the disk. There were no other fibrous structures directly connecting the disk with the posterior wall of the fossa.

To investigate the movement of the articular disk in recurrent luxations, 4 temporomandibular joints in three patients were studied with the arthrotomographs. All the superior articular cavities were extended anteriorly. On the mouth open in two patients with recurrent subluxation, the mandibular head accompanied with the articular disk located very anterior position from the articular tubercle. At this time, the retro-discal pad were stretched, but the relation between mandibular head and articular disk were normal findings: the mandibular head located on the central thin part of the articular disk. One of them showed anterior disk displacement with reduction. The other patient showed the bone cavity at the anterior slope of the articular tubercle. On the mouth open, the mandibular head and posterior band fitted that cavity. The other hand, remaining one patient was recurrent luxation on the left side. On the mouth open, the relation between mandibular head and articular disk were abnormal findings: The mandibular head located very anterior position, over the articular tubercle and anterior band of the disk. Therefore, the inferior articular cavity was extended, but the retro-discal pad was not stretched. The anterior slope of the articular tubercle was steep. The other side TMJ of this patient was recurrent subluxation and anterior disk displacement with reduction. On the mouth open, it was showed the hypermobility of mandibular head. But the relation between mandibular head and articular disk were normal findings. As mentioned above, in luxation and subluxation, it was made obvious that there were tow types about the relation between mandibular head and articular disk on the mouth open: one type was that mandibular head located anteriorly to the anterior band of the disk, the other was under the disk.

We reported that the cases of TMJ arthrosis patients have increased recently, and obtained good results with conservative treatment. But there have been few reports about long-term observation and evaluation of their cases. So we examined the revisited 33 cases of TMJ arthrosis experienced in recent 4 years from 1984 to 1987. We observed the following items such as symptoms of onset, chief complaints and change of symptoms between primary and secondary visit, conditions in the interval term, outcome of treatment in each visit, and so on. Concerning to the symptoms at primary and secondary visit, we observed pain, limited movement and clicking sound, then the same symptoms at primary and secondary visit were found in 20 cases, symptoms of secondary visit took turn for the remission were found in 4 cases, symptoms were changed in 3 cases and the worsened were 6 cases. As for the effect and progress of treatment, 18 cases were cured in primary treatment and same result was shown in secondary visit.

The mini-splint was applied to 21 patients with internal derangement of the temporomandibular joint (TMJ) who had failed in treatment by the manipulation technique. This appliance was constructed of two splints, which were built on the bilateral upper first bicuspids (teeth number 14 & 24, FDI) by methyl-meta-acrylate. As a result, the mean of the maximum interincisal distance was improved from 25.0 mm before to 41.0 mm after splint therapy. Among 21 patients, 18 patients were improved in interincisal opening, 12 patients were free from TMJ pain, and 3 patients were relieved from joint noise. Our studies indicate that this technique is useful as one of the treatment methods of TMJ internal derangement.

Two cases of temporomandibular arthrosis were reported. Case 1 was a 6 years 4 months old female with pain in her left mandibular region in moving her jaw. Opening of the mouth by herself was slightly limited. Clicking noise was seen and felt from both of her temporomandibular joints. She was in the dental developmental stage IIA by Hellman, and had deep overbite (5mm). Roentogenographic examination revealed a bony defect on her left condylar head. Treatment was performed with an activator. Pain was not felt and the mandibular opening recovered after 2 weeks of treatment. Roetogenographs showed no bony defect on her left condylar head after 5 months of treatment. Case 2 was a 3 years 2 months old male with clicking noise from both of his temporomandibular joints. There was no pain and no limitation of his mouth opening. He was in the dental developmental stage IIA by Hellman, and had large overjet (8mm). He has thumb sucking habit since the age of one year. He is now under regular observation.

The subjects were 37 female patients with juvenile TMJ arthrosis (T group) and 27 healthy females (N group) who visited the Dept. of Oral Surgery, Nagoya University Hospital or the Dept. of Dent-Oral Surgery, Nagoya University Branch Hospital. Following evaluations were made: 1) L6 to L7 angle 2) L6 to occlusal plane 3) L7 to occlusal plane 4) L6 to mandibular plane 5) L7 to mandibular plane 6) occlusal plane angle 7) mandibular plane angle Following results were obtained: 1. Significant differences between T group and N group were not seen in the occlusal plane angle. 2. A majority in the T group showed a mesial inclination of the lower second molar. 3. Mandibular plane angle in the T group was larger than that in the N group.