• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.437-448
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• 2021

The purpose of this study is to analyze morphological characteristics of maxillary primary molar's root and root canal. 268 children aged 3 - 7 years (175 boys, 93 girls) who had CBCT (152 children) and 3D CT (116 children) taken in Seoul National University Dental Hospital from January 2006 to April 2020 were included. The number of roots and root canals were analyzed in 1002 teeth without any root resorption or periapical pathologies. Curvature, angulation, length of root and root canal, as well as cross-sectional shapes of the root canal were analyzed in 218 teeth. By using Mimics and 3-Matics software, volume, surface area, and volume ratio of root canal was analyzed in 48 teeth. More than half of maxillary primary molars have 3 roots and 3 root canals. The degree of symmetry of root canal type was about 0.63 (Cohen's kappa coefficient). The most frequent shape of roots and canals was linear in 1^st primary molars and curved in 2^nd primary molars. Angulation, length of root and root canals was the largest on palatal roots. Most teeth showed ovoid or round shapes at apex. The largest root canal volume, surface area, volume ratio was found in the palatal roots.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.115-123
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• 2003

Study Design: A retrospective clinical and radiographic review. Objectives: The purpose of this study was to suggest recycling bone autotransplantation with extracorporeal heat-treatment as one of favorable reconstruction method for malignant bone tumors of pelvis through 3 cases. Summary of Literature Review: There are many biologic and nonbiologic reconstruction method in pelvic reconstruction. Cases: Case 1- A 20-year-old women had chief complaint of right hip and thigh pain started 3 months ago and done curettage and bone cementing at right ilium at other hospital. She had impression of malignant bone tumor and undergone postoperative radiation therapy for 6 cycles. After that she was referred to our hospital and undergone wide excision of right ilium and recycling bone autotransplantation with extracorporeal heat-treatment at 132 degree celsius for 2 minutes internal fixation with pelvic reconstruction plate and total hip replacement arthroplasty (ABG$^{(R)}$). There was no evidence of distant metastasis and revealed well-differentiated osteosarcoma on postoperative pathology. Neither adjuvant nor neoadjuvant chemotherapy were done. Case 2- A 56-year-old women who suffered right thigh pain for 3 months was detected radiologic abnormality at right pelvis. After incisional biopsy, osteosarcoma was diagnosed. We had undergone wide excision of right ilium and recycling bone autotransplantation with extracorporeal low heat-treatment at 65 degree celsius for 30minutes internal fixation with pelvic reconstruction plate and total hip replacement arthroplasty (ABG$^{(R)}$). There was no evidence of distant metastasis and revealed high-grade osteosacoma which was fibroblastic type on postoperative pathology. Adjuvant chemotherapy (HDMTX, ADR, CDDP) was done immediate after wound healing was completed. Case 3- A 46-year-old women was incidently found mass at left ilium which was suspected chondrosarcoma. We had undergone wide excision of left ilium and recycling bone autotransplantation with extracorporeal low heat-treatment at 65 degree celsius for 30minutes internal fixation with pelvic reconstruction plate and total hip replacement arthroplasty (Protek$^{(R)}$). There was no evidence of distant metastasis and revealed chondrosarcoma which was graded II/III on postoperative pathology. Results: Oncologic and functional outcome at final follow-up were for case 1, final follow-up time was 7 years, is no evidence of disease and functional score is 53% according to Ennecking et al. During follow-up, evidence of radiologic union was at about 1 and 6 months after operation. The case had breakage of pelvic reconstruction plate and some resorption of autotransplated bone, but no symptom present. For case 2, final follow-up was 3 years and 6 months, is no evidence of disease and functional score is 60%. For case 3, final follow-up was 7 months, no evidence of disease and functional score is 63% which is improving state. Discussion: 3 cases which were undergone recycling bone autotransplantation with extracorporeal heat-treatment and total hip replacement arthroplasty had relatively successful oncologic and functional outcome. Taking account that difficulty in using allograft in Korea this method is thoght to be one of the useful way to reconstruct pelvis after resection of primary malignant bone tumor of the pelvis.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.273-284
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• 1996

Embryos and fetuses are more sensitive to various environmental agents than are adults or children. The biological effects such as intrauterine death and malformation are closely connected with prenatal exposure very various agents. The sensitivity of these embryonic/fetal effects depends on the stage of pregnancy. From the viewpoint of fetal development, embryonic and fetal stages can be divided into three stages : Preimplantation, organogenetic and fetal. Each stage corresponds to 0 to 4.5days, 4.5 to 13.5days, and 13.5days of gestation in mice, respectively. Many studies on the biologcal effects of mice irradiated by ${\gamma}-rays$ at various stages during organogenesis and fetal period have been performed. Based on these results, the dose-effect and dose-response relationships in malformations, intrauterine death, or retardation of the physical growth have been practically modeled by the ICRP(International Commission on Radiological Protection) and other international bodies for radiation protection. Many experimental studies on mice have made it clear that mice embryos in the preimplantation period have a higher sensitivity to radiation for lethal effects than the embryos/fetuses on other prenatal periods. However, no eratogenic effects of radiation at preimplantation stages of mice have been described in many textbooks. It has been believed that 'all or none action results' for radiation of mice during the preimplantation period were applied. The teratogenic and lethal effects during the preimplantation stage are one of the most important problems from the viewpoint of radiological protection, since the preimplantation stage is the period when the pregnancy itself is not noticed by a pregnant woman. There are many physical or chemical agents which affect embryos/fetuses in the environment. It is assumed that each agents indirectly effects a human. Then, a safety criterion on each agent is determined independently. The pregnant ICR mice on 2, 48, 72 or 96 hours post-conception (hpc), at which are preimplantation stage of embryos, were irradiated whole body Cesium-gamma radiation at doses of 0.1, 0.25, 0.5, 1.5, and 2.5 Gy with dose rate of 0.2 Gy/min. In the embryos from the fetuses from the mice irradiated at various period in preimplantation, embryonic/fetal mortalities, incidence of external gross malformation, fetal body weight and sex ratio were observed at day 18 of gestation. The sensitivity of embryonic mortalities in the mice irradiated at the stage of preimplantation were higher than those in the mice irradiated at the stage of organogenesis. And the more sensitive periods of preimplantation stage for embryonic death were 2 and 48 hpc, at which embryos were one cell and 4 to 7 cell stage, respectively. Many types of the external gross malformations such as exencephaly, cleft palate and anophthalmia were observed in the fetuses from the mice irradiated at 2, 72 and 96 hpc. However, no malformations were observed in the mice irradiated at 48 hpc, at which stage the embryos were about 6 cell stage precompacted embryos. So far, it is believed that the embryos on preimplantation stage are not susceptible to teratogens such as radiation and chemical agents. In this study, the sensitivity for external malformations in the fetuses from the mice irradiated at preimplantation were higher than those in the fetuses on stage of organogenesis.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.660-668
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• 1995

Background: It is said that tuberculous pleuritis responds well to anti-tuberculous drug in general, so no further aggressive therapeutic management is unnecesarry except in case of diagnostic thoracentesis. But in clinical practice, we often see some patients who need later decortication due to dyspnea caused by pleural loculation or thickening despite several months of anti-tuberculous drug therapy. Therefore, we want to know the clinical difference between a group who received decortication due to complication of tuberculous pleuritis despite of anti-tuberculous drug and a group who improved after 9 months of anti-tuberculous drug only. Methods: We reviewed 20 tuberculous pleuritis patients(group 1) who underwent decortication due to dyspnea caused by pleural loculation or severe pleural thickening despite of anti-tuberculous drug therapy for 9 or more months, and 20 other tuberculous pleuritis patients(group 2) who improved by anti-tuberculous drug only and had similar degrees of initial pleural effusion and similar age, sex distribution. Then we compared between the two groups the duration of symptoms before anti-tuberculous drug treatment and pleural fluid biochemistry like glucose, LDH, protein and pleural fluid cell count and WBC differential count, and we also wanted to know whether there was any difference in preoperative PFT value and postoperative PFT value in the patients who underwent decortication, and obtained following results. Results: 1) Group 1 patients had lower glucose level{$63.3{\pm}30.8$(mg/dl)} than that of the group 2{$98.5{\pm}34.2$(mg/dl), p<0.05}, and higher LDH level{$776.3{\pm}266.0$(IU/L)} than the group 2 patients{$376.3{\pm}123.1$(IU/L), p<0.05}, and also longer duration of symptom before treatment{$2.0{\pm}1.7$(month)} than the group 2{$1.1{\pm}1.2$(month), p<0.05}, respectively. 2) In group 1, FVC changed from preoperative $2.55{\pm}0.80$(L) to postoperative $2.99{\pm}0.78$(L)(p<0.05), and FEV1 changed from preoperative $2.19{\pm}0.70$(L/sec) to postoperative $2.50{\pm}0.69$(L/sec)(p<0.05). 3) There was no difference in pleural fluid protein level($5.05{\pm}1.01$(gm/dL) and $5.15{\pm}0.77$(gm/dl), p>0.05) and WBC differential count between group 1 and group 2. Conclusion: It is probable that in tuberculous pleuritis there is a risk of complication in the case of showing relatively low pleural fluid glucose or high LDH level, or in the case of having long duraton of symptom before treatment. We thought prospective study should be performed to confirm this.