Nihon Ago Kansetsu Gakkai Zasshi最新文献

An ankylosis of temporomandibular joint (TMJ), which may be defined as the disease with the limitation of the movement of TMJ resulted from inflammations or traumas followed by fibrosis or ossification, could lead to the disturbance of mandibular development in childhood. In this report, we have experienced a case of unilateral TMJ ankylosis suspected to be caused by forceps delivery in 7-years old boy. The patient called on our hospital suffering from severe trismus and facial asymmetry. Following the conservative treatment, the operative relief of the ankylosis was performed with the procedure of the amputation of coronoid processus and condylar neck at the age of 14. Then orthodontic treatment was carried out to build a stabilized occlusion at 7 months after the operation. Five years follow-up observation elucidated that mandible developed normally without any recurrence. Judging from both clinical aspects and cephalometric analysis the result is very satisfying not only functionally but esthetically.

The authors examined arthrotomographies of 89 patients (96 joints) with closed lock of the temporomandibular joint to clarify the frequency of disk deformity correlated with disk perforation, bone change and patients' age. The disk configurations were divided into 3 types, those were type-1-elongated and preserved shape of the disk, 39 joints, type 2-folded disk, 11 joints, and type 3-massed disk, 46 joints. The frequency of disk deformity was 66.7% (64 joints). The numbers of disk perforation, (and bone change) in each type were type 1-2 (5) joints, type 2-1 (1) joint, and type 3-11 (13) joints. The average ages of each type were type 1-28.1 years, type-2-27.2 years, and type 3-40.1 years. These results indicate that high percentage of disk deformations exist in the closed lock patients with degenerative changes of the soft and hard parts of the temporomandibular joint.

The Color X-ray CT image processing system developed previously was improved to reconstruct three-dimensional images of coronal, sagittal, and oblique processing from the original axial data of an X-ray CT scanner. The color-reformatted images reconstructed for temporomandibular joints soft and hard tissues clearly and various soft tissues such as muscular and fatty tissues were easily distinguishable. Expansion of the desired part of the image allowed detailed examination of that part with a high distinction. The versatility of the present system can be utilized in clinical diagnoses of dental diseases as well as diseases of other parts of body.

Microvascular architecture of the temporomandibular joint (TMJ) was studied three-dimensionally in the rabbit using the vascular casting/scanning electron microscope method. TMJ was found to be a well-vascularized organ with the most dense vascular distribution in the retro-discal region, but no blood vessels were observed in the articular disc. Morphologically the vascular networks in the upper and lower layers of the transitional area of the retro-discal region into the articular disc were different. The upper layer had a coarse, cap-shaped network beneath the synovial membrane of the superior articular space, whereas a fine and flat network was observed in the corresponding region of the lower layer. The capillaries overlying these networks took winding courses and formed hairpin-like loops at the discal ends of the networks in both layers, but the winding arrangement was more conspicuous in the lower layer, whereas the loop formation was more marked in the upper layer. The result indicate that in addition to the range of movement, the upper and lower layers may be functionally different in the production of synovial fluid and nutritional supply.

In general, patients who have trismus as chief complaint often have acute symptoms, but limited number of these patients have chronic trismus. We studied 51 patients (mean age; 18y 4n) with severe skeletal class III (less than ANB less than or equal to O), who need surgical treatment. Three types were classified according to the movement of the mandibular head at the maximum mouth opening at their first visit. A-type; the mandibular head hardly move. B-type; it dose not move beyond articular eminence. C-type; it moves beyond articular eminence. These classifications were applied to the both sides of the mandibular head in the 51 patients to divide into 5 types (Type AA, Type AB, Type BB, Type BC, Type CC). Those patients were analyzed according to these five types. The results obtained were as follows; 1) Seventy-three percent of all the cases were female in this study. Sixty-five percent of both the sexes had chronic trismus without having subjective symptoms on the mandibular joints in their daily lives. Type AA, AB, BB, and BC accounted for 12%, 6%, 31%, and 16% respectively. 2) There were fewer contacts in the upper posterior antagonist teeth in AA and AB; particularly at 5. In all the cases of Type CC, contacts with the antagonist tooth 5 were seen. 3) As a conclusion, movement of the mandibular head in the patients with trismus are found to have a characteristic limitation at the maximum mouth opening and the stress points in the occlusal contacts at the centric occlusion to be the posterior area.

Sixty-six joints in 49 patients with mandibular condylar fracture were investigated by means of long-term follow-up observation. The group of patients consisted of 39 males and 10 females with ages from 15 to 75 years. The classification of the fractures was follows: MacLennan type 1; four, type 2; four, type 3; 39, and type 4; 39 joints respectively. Treatment was as follows: 25 joints were by conservative therapy, 31 joints were by surgical fixation, and 10 joints condylectomy. The follow-up period of observation ranged from 18 months to 10 years and one month an average of five years and seven months. Clinical assessment was based upon Nakatomi's dysfunction index on mandibular condylar fracture, of which the criteria are as follows; Excellent (No clinical dysfunction sign on the TMJ), Fair (Slight pain, noise, and limited range of motion of the mandible, but clinically no affected mastication), Poor (Moderate dysfunctioned jaw), and Failure (Severe dysfunctioned jaw). 23 joints in 18 patients were ranked as having excellent results. 31 joints in 22 patients were assessed as fair. Ten joints in seven patients were defined as poor, and the remaining two joints in two patients were failures. The overall success rate was 81.7%. There are no statistical differences between patient's groups based on age, sex, uni/bilateral modality, with/without other concomitant fracture, surgical/conservative procedure, location and form of fractures, and duration of period from injury. These results indicated that the conservative procedure would be the first choice as a reasonable and less invasive procedure for functional repair of mandibular condylar fracture. On the other hand, as most patients had some dysfunction sign on the TMJ after mandibular condylar fracture, a more appropriate treatment, surgical or otherwise, should be found.

It is seemed to be really important, when making a selection on the treatment for rheumatoid arthritis, to gain an insight into progress and activity of the disease. This analysis was taken in order to look upon the clinical symptoms and the radiographic abnormalities of the temporomandibular joints, obtained from fifteen rheumatoid arthritis patients who has visited on our department, since 1974. Ten patients (66.7%) had clinical evidences of temporomandibular joint. The most frequent symptom was pain on movement, followed by disturbances on mouth opening and crepitation. Patients who had been suffering from the disease for a long period offered more frequent clinical evidences. The acute phase symptoms, such as disturbances on mouth opening, swelling and oppressive pain in the preauricular area, was found in one patients. All of the patients showed some radiographic abnormalities. We've devised a criteria on the degree of condylar absorption on the purpose of comparison to the other abnormalities. The degree 1 was found in 3 joints, the degree 2 in 12 joints, the degree 3 in 14 joints, and the degree 4 in 7 joints. An absorption on the articular fossae and the tubercles were well along with this degrees. The higher degree the more frequent of clinical evidences in each joints was disclosed. And the period of the disease was related on the degrees, too. We can expect the bone scintigraphy by using 99mTc-MDP to be a good way for expression of the activity of the disease.

In recent years, TMJ dysfunction is reported to be increasing, but at present its etiology is not clear now. We have been studying the chewing movements, which are the most important functional mandibular movements. The possibility is indicated that the interference at the non-working side of lateral movement have a harmful effect on the functional occlusion system. In this study, the effect of the interference at the non-working side on chewing movements was investigated. 30 people were selected as the interference group with the interference at the non-working side of lateral movement, and 10 people without that interference as the control group. the interference group was divided into two groups, interference normal group without TMJ dysfunction and interference abnormal group with TMJ dysfunction. Jaw movements were recorded and analysed by Sirognathograph Analysing System II. The results were as follows; Some characteristic patterns in the frontal plane were observed in the chewing movements of the interference group. 1. On interference side chewing, a concave opening pattern was significantly observed. Especially of the interference abnormal group, the working side deviate reverse crossover opening pattern was significantly observed. 2. On non-interference side chewing, a closing path with a step or a concave part was significantly observed.

Clinical retrospective investigation was conducted on mandibular condylar fractures of 100 hospitalized cases at the Department of Oral Surgery, Kyoto University Hospital during the period from 1973 to 1983. The following results were obtained, 1. There were 74 males and 26 females. The age of the patients at the time of injury ranged from 4 to 78 years old. The average age was 28.1 years old. 2. Twenty-six patients were treated within a week of injury, 22 cases within 2-weeks and 33 cases were treated after more tham 3 weeks. 3. Of the 100 cases, 70 were unilateral fractures and 30 were bilateral. The incidence of the concomitant fractures of the mandible were higher in bilateral than in unilateral condylar fractures. 4. On fracture level and form 130-site in 100 patients were divided according to the classification of Maclennan and Kubo. Dislocated and high condylar fractures were most frequently observed. 5. Surgical reduction was mainly achieved in low neck fracture, and the contrary conservative treatment was observed in the higher level fracture. On the other hand condylectomy was infrequently indicated in the dislocated head fracture.

A female patient of fifteen years old with anterior crossbite was treated orthodontically with multi-bracket system. During the orthodontic treatment clicking and trismus were appeared. According to the consultation, it was found that the TMJ disorder was in the stage of the closed lock. The patient was treated with the manipulation technique and the anterior repositioning appliance was applied. After three months, the pain and trismus were relieved. The maxillary arch was expanded laterally to eliminate the premature contact caused by the maxillary and mandibular canines. Consequently, intercanine width of the maxillary arch was increased and the cuspal interference was disappeared. After three month observation, it seemed that the symptoms of TMJ were recovered. Then, orthodontic appliances were removed and the retainers were set. It was concluded that the examination of TMJ condition may be necessary for orthodontic patients with anterior crossbites.