Taehan Ch'ikkwa Uisa Hyophoe chi最新文献

The patient was a 12-year-old female with Angle's Class II malocclusion accompanying congenital missing of upper premolar. The results were as follows: 1. After autotransplantation, orthodontic treatment time was 26 months. 2. In panoramic and periapical radiographs demonstrated closed root apex of transplanted tooth. 3. Autotransplanted tooth responses about vitality test. 4. Periodontal probing was within normal limits in the transplanted area.

This study was undertaken to evaluate the cytotoxic effects of 8 root canal sealers. Fibroblasts of human gingiva were employed to determine the comparative cytotoxicity of the 8 experimental materials. The results of this experiment were analyzed by counting the cells on the 2nd, 4th and 7th day. The results were as follows: 1. All experimental groups exhibited significant decrease of cell numbers in compared with control. All experimental groups showed cytotoxicity at 2, 4, 7 days (P less than 0.05). 2. All experimental groups except AH26 exhibited the decrease of mean of cell numbers with increasing time. 3. On the 7th day, AH26' Tubli-Seal and NOgenol showed lower cytotoxic effect than Apatite root sealer (Type I, II, III), N2 universal and Sealapex. 4. There was no statistical significance of cytotoxicity among the experimental groups (Type I, II, III) of Apatite root sealer (P greater than 0.05).

Author experienced a case of tubular type, and a case of solid & basaloid type in adenoid cystic carcinoma and presented these cases through the review of literature. The paralysis was found. Both cases showed perineural, muscular tissue and bony invasion. Respectively hemimaxillectomy, and subtotal maxillectomy were operated. The origin of adenoid cystic carcinoma was considered as myoepithelial cell combined with intercalated duct reserve cell.

MR imaging offers the superior evaluation of soft tissue structures without the use of ionizing radiation or intracapsular injection. In addition, the influence of MR imaging on the field of T.M.J. may be quite substantial. The purpose of this study is to demonstrate the principles of MR imaging, to determine the normal and abnormal T.M.J. imaging, and to compare MR imaging with transcranial, arthrography, tomography, and computed tomography.

The author has studied on treatment of internal derangement of the temporomandibular joint induced by incision of the retrodiscal ligament, and on an extracapsular surgical treatment method composed of lower repositioning of the mandibular condyle with oblique osteotomy of the ramus on the animals and 5 patients with internal derangement of the T.M. joint. To induce internal derangement on experimental animals, 5 Malaysian monkeys aging around 2 years and weighing about 3kg. were used, the retrodiscal ligament of the left temporomandibular joint was incised, and 1mm lower repositioning surgery of the condyle was performed 3 weeks after. The animals were observed and sacrificed on the 1st, 2nd, 3rd, 4th and 5th weeks thereafter, and the temporomandibular joints and their surrounding tissues were obtained to make microscopic specimens stained with Hematoxylin-Eosin and with Van Gieson method and patient treated by means of lower reposition surgery and 5 patients treated have been observed clinically. And 5 patients treated have been observed clinically. The results obtained were as follows: 1. Internal derangement of the T.M. joint occurred in by resecting retrodiscal ligament. 2. A lots of bone resorption on articular eminence was shown, 1-2 weeks after lower repositioning surgery. 3. Bone healing on articular eminence was shown, 3-5 weeks after lower repositioning surgery. 4. Displased articular disks came back to normal positions by lower repositioning surgery. 5. 5 patients with internal derangement completely treated by application of lower repositioning surgery.

The purpose of this study was to observe the changes of the third molars following the extraction of second molars by orthopantomograms. The subjects were consisted of 96 cases in upper second molar extraction, 74 cases in lower second molar extraction. The obtained results were as follows: 1. The favourable eruption condition of upper third molar appeared in both groups with pre-extraction angle under 25 and pre-extraction angle above 25. 2. More favourable eruption condition of lower third molar appeared in group with pre-extraction angle under 25 than the other group with pre-extraction angle above 25. 3. The favourable eruption condition of upper third molar appeared in both group extracted in Nolla's Stage 4, 5 and Nolla's Stage 6,7,8. 4. More favourable eruption condition of lower third molar appeared in group extracted in Nolla's Stage 4, 5 than the other group extracted in Nolla's Stage 6,7,8.

Authors experienced a case of low grade mucoepidermoid carcinoma in 48-year-old female and a case of low grade central mucoepidermoid carcinoma in 51-year-old female, respectively. The former occurred in right mandibular angle and showed multilocular radiolucent area surrounded by sclerotic rim but perforation of cortical bone connected with tumor mass in oral cavity radiographically. The latter occurred in left mandibular angle and ramus. Radiographic feature showed large radiolucent area in left mandibular angle and ramus, and destruction of coronoid process but intact condylar process. The origin of the latter might be mucus secreting cells of lined epithelium in dentigerous epithelium. In two cases metastases were not found.

Recently ceramic bracket is introduced to orthodontics. Many orthodontists are attempt to use it for improving esthetics during orthodontic treatment. Especially the adult patients want to be treated with less conspicuous braces. So it's usage will be increased. But the information about the physical properties, proper management, and important cautions are not well known to most of clinicians. Ceramic bracket is not the exact esthetic alternatives for metal bracket. So it is necessary to review some recent articles for proper clinical usage of ceramic bracket. The authors attempt to introduce some clinical considerations for using ceramic bracket. The contents are as followed. I. Introduction II. Type and physical properties of ceramic bracket III. Clinical usage of ceramic bracket 1. bonding 2. bonding materials 3. debonding 4. others IV. Recycling ceramic bracket.

From 1965 to 1974, the total number of the orthodontic patients who visited Seoul National University Hospital was only about 1000. But in the last several years the number has been increasing so rapidly that we have about 1000 new orthodontic patients every year. This made it necessary to undertake an epidemiologic study on them so that we can accommodate their orthodontic needs adequately. Accordingly, the present study was done in an attempt to provide reliable quantitative information regarding the characteristics of malocclusion-Angle's classification etc.--of patients who visited Department of Orthodontics, Seoul National University Hospital from 1985 to 1989. The total number was 3305. This study sought to determine the annual trend in total number during 5 years, frequency in each age and sex group and distribution according to Angle's classification. It was found that: 1. Total number of orthodontic patients has been increasing and the number of female patients was 1.55 times as high as that of male. 2. Percentage of Class III malocclusion has been increasing, but that of Class I decreasing. Each percentage of Class I, Class II div. 1, Class II div. 2 and Class III was 35.92%, 13.40%, 1.54%, and 49.14%. 3. Percentages of 8 to 12-year-old group and 12 to 18-year-old group showed decreasing trends, but that of adult patients showed increasing trend.