본 연구는 두 가지 관점, 즉 다이오드레이저를 구강연조직에 접촉식으로 조사하여 조직을 절제할 경우 첫째 심부조직에서의 온도 상승 정도에 대한 분석 평가, 둘째 절제에 따른 조직의 열적 응고에 대한 조직학적 분석 평가를 위해 시도되었다. 연구를 위해 도축된 소의 혀 배면으로부터 5.0mm깊이에 T형 열전대(type T thermocouple)를 설치하고 조사조건에 따른 레이저절제 도주의 온도변화를 측정하고, 또한 해당조사부위의 조직을 대상으로 통법에 의한 H-E염색 후 조직학적 측면에서 열적 응고상을 검색하여 Nd:YAG레이저의 경우에서와 비교하였다. 즉 파장815nm의 다이오드레이저를 0-10W의 출력, 50Hz와 연속파의 주파수조건에서 접촉식으로 조사하였으며, 또한 파장1064nm의 Nd:YAG레이저를 0-10W의 출력, 50Hz와 100Hz의 주파수 조건에서 접촉식으로 조사하였다. 레이저의 접촉조사시 레이저광섬유 첨단부에서 10(10gm의 일정한 압력과 25mm/sec의 이동속도로 조직을 절제하였다. 레이저가 접촉조사된 조직부위를 통법에 의해 조직학적으로 H-E염색을 시행하였으며, 계측현미경을 이용하여 10배율 아래에서 조직절제의 폭과 깊이, 측방 및 하방 쪽으로 열적 응고의 폭을 계측하였다. 계측치에 대한 통계학적 처리결과 조직절제의 폭과 측방쪽으로 열적응고의 폭은 다이오드레이저에와 Nd:YAG레이저에서 같은 정도를 나타냈다. 조직절제의 깊이는 Nd:YAG레이저에서에 비해 다이오드레이저에서 더 깊었다. 하방쪽으로의 열적응고의 폭은 Nd:YAG레이저를 10Hz의 조건에서 조사한 경우에서 가장 넓었으며, 다이오드레이저를 50Hz와 연속파의 조건에서 조사한 경우에서 가장 좁았다. 레이저절제 도중 심부조직에서의 온도변화는 다이오드 레이저에서와 Nd:YAG레이저에서 모두 출력이 증가함에 따라 상승되었으며, 다이오드레이저에서 보다 Nd:YAG레이저에서 더 높이 상승되었다. 결론적으로 본 연구에서 시도된 조사조건 범위 이내에서는 구강연조직 절제시 다이오드레이저가 펄스형 광섬유 전달식 Nd:YAG레이저 보다 심부조직에서의 낮은 온도상승과 하방쪽으로의 좁은 열적 응고의 폭을 보이면서 우수한 조직절제효과를 나타냈다.

Fixed orthodontic appliances for the treatment of malocclusion has iatrogenic side effect such as demineralization of enamel, gingivitix and gingival hyperplasia. The purpose of this study is to longitudinally investigate the salivary microorganisms and immunoglobulin A after delivery of fixed orthodontic appliances for 10 months. Eight orthodontic patients were included in this study and the author has investigated the numbers of general bacteria, Streptococcus mutans Staphylococcus aureus and concentration of immunoglobulin A from unstimulated whole saliva. The author examined these parameters at prebracketing, 1 month after, 4 months after, 7 months after and 10 months after delivery of fixed orthodontic appliances. The obtained results were as follows : There were significant increases in the number of salivary general bacteria, Streptococcus mutans and Staphylococcus aureus after delivery of fixed orthodontic appliances The numbers of general bacteria were significantly increased at 1 month after (p<005), 4 months after (p<0.05), 7 months after (p<0.01), compared with prebracketing. However it showed no difference at 10 month after compared with 7 months after bracketing. The Numbers of Staphylococcus aureus were significantly increased at 1 month after (p<0.05), 4 months after(p<0.01), 7 month(p<0.01), compared with prebracketing. However it showed decreasing pattern at 10 months after compared with 7 months after bracketing. There was no significant difference in the concentration of immunoglobulin A after delivery of fixed orthodontic appliances.

The authors treated a 58-year old female patient who had come to the Department of Oral Medicine, KNUH due to the chief complaints of gingival enlargement and bleeding on the upper and lower jaw. The lesions were diagnosed as cyclosporin-A induced gingival enlargement by patient's history and clinical examination. The patient was treated with gingivectomy using pulsed Nd:YAG laser. After gingivectomy the wound was compressed with 0.1% chlorhexidine-soaked gauze to prevent relapse of the lesion. Good healing process was observed and there were no recurrences until 3-month follow-up visit. From the results of this clinical trial it was suggested that a pulsed Nd:YAG laser gingivectomy would be helpful for the treatment of cyclosporin-A induced gingival enlargement in renal transplant patients.

This study was performed to investigate the clinical features of internal derangement of temporomandibular joint. For this study, 117 patients with temporomandibular disorders and 81 dental students without any signs and symptoms of temporomandibular disorders were selected as the patients group and as the control group, respectively. Preferred chewing side, Angle's classification, lateral guidance pattern, maximal mouth opening range, and affected side were recorded clinically. Head and shouldeer posture was measured in a groundplate on which square diagram of five centimeters each had been drawn, and cephalograph was also taken for measurement of head and neck posture. Sonopak of Biopak system (Bioresearch inc., USA) was used to record joint vibration for evaluation of internal healthy status of temporomandibular joint. The data collected were analyzed by SAS statistical program. The results of this study were as follows : 1. Frequency of left side chewing subjects was higher in patients than in control group, but there was no difference in distribution of subjects by Angle's classification. Other types was prvalent in patients whereas group function was more in control group for lateral guidance pattern. 2. As to lateral guidance pattern by clinical diagnosis, patients with internal derangement and/or degenerative joint disease showed higher frequency was consistent with the result by Sonopak impression. 3. There was no difference for shoulder height between the two groups, however, tilting of head and backward extension of cervical spine was more frequent in control group. 4. Acromion was positioned more anteriorly in patients with internal derangement and/or degenerative joint disease than in control group and angle between eye and tragus was larger in patients. Patients with degenerative joint disease showed more flexed head posture than control group did in cephalometric profile. 5. Maximal mouth opening range in patients with internal derangement was the least in all subgroups in patients classified by Sonopak impression.

This study was performed to investigate the factor that might affect mandibualr body rotation. For the study, 115 patients with temporomandibular disorders and 35 dental students without angy signs and symptoms of temporomandibular disorders were randomly selected as the patient group and the contreol group, respectively. Preferred chewing side, Angle' classification, lateral guidance pattern, and affected side were clinically recorded, and the amount of Mandibular body rotational torque movement was measured in wide opening and closure, in right and left excursion with vertical and lateral distance in frontal plane, right and left rotational angel in horizontal and in frontal plane. Masticatory muscle activity of anteriorocclusal contact pattern on maximal hard biting were also observed synchronously with BioEMG and T-Scan , respectively. The observed items were muscle activity of anterior temporalis and superficial masseter, and tooth contact status related to contact number, force, duration, and occlusal unbalance between right and left arch. The data collected were analyzed by SAS statistical program. The results of this study were as follows : 1. Mean value of vertical distance in frontal plane in wide opening and closure was more in control subjects than in patients, but there was no difference for rotational angle. In right excursion, rotational angles were greater in patient group than in control group. 2. Comparison among the subjects by preferred chewing side did not reveal any significant difference, but comparison among patients by affected side showed more rotational amount in bilaterally affected patients than in unilaterally affected patients. 3. Comparison among the subjects by Angle's classification or lateral guidance pattern revealed no difference. There was also no difference between preferred chewing side and contralateral side, and between affected side and contralateral side. 4. Positive correlation in madibular rotational torque movements were observed among vertical distance, total horizontal rotation angle, electromyographic activity of anterior temporalis, tooth contact number, and tooth contact force but total frontal rotation angle almost did not show any correlation with other variables except vertical distance.

The subjects chosen for the study were 2,941 dentists who have been registered in the Seoul Dental Association in 1997. Questionnaires were delivered to the dentists, and 1,133 questionnaires of these were returned. The basic dental of repliers, medical accident experiences, and general thoughts on the dental care and medical accident had been reviewed. Many dentists had appeared to be exposed to the medical accidents and disputes, and the rate of the experience of these cases was also high. In the dental practice, the execution degree of the duties as a dentist was lower than the perception of the duties as a dentist, while the perception was good. However, in spite of carefully following the duties as a dentist, it seemed to be impossible to fundamentally prevent the medical accidents. Thus, dentists should always predict the possibilities of the medical accidents, and it is necessary to establish the impartial dental institutions and organizations through which dentists can settle the medical disputes.

In identifying bodies that are severely decayed or damaged, methods using fingerprints and various biochemical tests are known to have its limits. To overcome this, forensic odontological method which is based on the analysis of the cranium, tooth and dental restoration is used to enhance the accuracey of individual identification. For this reason, I have come to analysis of the dental materials that exists between the teeth that is perceived to have been previously restored and the one adjacent to it. By analyzing the constituents of gold crown-restored, non-precious metal-restored, gold inlay-restored and amalgam -restored teeth, and adjacent teeth using EDX(energy dispersive X-ray microanalysis) which was invented to analyze very small amount of elements, the nature of the restoration could be predicted and the results obtained were as follows. 1. Some of constitute of gold alloy was extracted from residual cement of gold crown restoration, but that was not extracted from the restored tooth and the one adjacent to it. 2. Some of constituents of non-precious metal alloy was extracted both in the residual cement on the tooth with no-precious metal restoration and in the tooth with the restoration itself. However, none of its constituents were found in the tooth adjacent to it. 3. Some of constituents of gold alloy were found in the residual cement of gold inlay, but they were not found in the restored tooth and the adjacent tooth. 4. Some of constituents of amalgam alloy were found both in tooth restored with amalgam and in the adjacent tooth. From the results obtained above, it is possible to utilize the data obtained from analyizing residual dental materials in a more effective way. This data compensates for the lost data due to any harm done to the restorations prior to individual identification and further enhances the accuracy. Therefore, it could be concluded that this process of analyzing residual dental materials could be beneficial to individual identification in the area of forensic odontoldogy.