• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.516-526
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• 2004

Polymerization shrinkage of photoinitiation type composite resin cause several clinical problems. The purpose of this study was to evaluate the shrinkage strain stress, linear polymerization shrinkage, compressive strength and microhardness of recently developed composite resins. The composite resins were divided into four groups according to the contents of matrix and filler type. Group I : $Denfil^{TM}$(Vericom, Korea) with conventional matrix, Group II : $Charmfil^{(R)}$(Dentkist, Korea) with microfiller and nanofller mixture, Group III : $Filtek^{TM}$ Z250(3M-ESPE, USA) TEGDMA replaced by UDMA and Bis-EMA(6) in the matrix, and Group IV : $Filtek^{TM}$ Supreme(3M-ESPE, USA) using pure nanofiller. Preparation of acrylic molds were followed by filling and curing with light gun. Strain gauges were attached to each sample and the leads were connected to a strainmeter. With strainmeter shrinkage strain stress and linear polymerization shrinkage was measured for 10 minutes. The data detected at 1 minute and 10 minutes were analysed statistically with ONE-way ANOVA test. To evaluate the mechanical properties of tested materials, compressive hardness test and microhardness test were also rendered. The results can be summarized as follows : 1. Filling materials in acrylic molds showed initial temporary expansion in the early phase of polymerization. This was followed by contraction with the rapid increase in strain stress during the first 1 minute and gradually decreased during post-gel shrinkage phase. After 1 minute, there's no statistical differences of strain stress between groups. The highest strain stress was found in group IV and followed by group III, I, II at 10 minutes-measurement(p>.05). In regression analysis of strain stress, group III showed minimal inclination and followed by group II, I, IV during 1 minute. 2. In linear polymerization shrinkage test, the composite resins in every group showed initial increase of shrinkage velocity during the first 1 minute, followed by gradually decrease of shrinkage velocity. After 1 minute, group IV and group III showed statistical difference(p<.05). After 10 minutes, there were statistical differences between group IV and group I, III(p<.05) and between group II and group III(p<.05). In regression analysis of linear polymerization shrinkage, group II showed minimal inclination and followed by group IV, III, I during 1 minute. 3. In compressive strength test, group III showed the highest strength and followed by group II, IV, I. There were statistical differences between group III and group IV, I(p<.05). 4. In microhardness test, upper surfaces showed higher value than lower surfaces in every group(p<.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.709-727
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• 2001

The pattern of programmed cell death(PCD) has been examined during the early developmental period of development in mouse embryos, from embryonic day 4.5(E4.5) to E11.5 Embryos from Balb/c breedings were harvested at various embryonic stages between E4.5 and El1.5. Cell death was analysed by in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL) staining in tissue sections and whole embryos. At the blastocyst stage(E4.5), a very few apoptotic cells were found in the inner cell mass of the blastocyst. In the early egg cylinder stage(35.0-5.5), a few apoptotic cells were detected in the embryonic ectoderm, the embryonic endoerm and the proamniotic cavity. In the advanced egg cylinder stage(E5.5-6.5), TUNEL-posifive cells were observed in the extra-embryonic ectoderm and extra-embryonic endoderm as well as in the embryonic ectoderm, embryonic visceral endoderm and proamniotic cavity. In the streak stage(E6.75-7.75), many TUNEL-positive cells were found in the ectoplacental cone. In contrast, only very few apoptotic cells were found in the chorion and extra-embryonic endoderm in extra-embryonic regions. In intra-embryonic region, a few apoptotic cells were randomly found in the embryonic ectoderm, mesoderm and visceral endoderm. At the early somitogenesis stage(E8.0-8.5), most apoptotic cells were observed in the most cranial portion of neural fold (neural ectoderm and adjacent ectoderm). At the mid somitogenesis stage(39.0-9.5), the otic placode first showed TUNEL-positive at this stage. Small number of TUNEL-positive cells were also first seen around optic placode and branchial arches. Three streams of TUNEL-positive cells were clearly seen in the cranial region at 59.5-9.75. At E10.5, apoptotic cells were localized in the developing eye, the junctional portion of medial nasal, lateral nasal and maxillary processes, the lateral portion of branchial arches, the junction of bilateral mandibular processes, and apical ectodermal ridges of limb buds. At E11.5, apoptotic cells were noticeably decreased in most area, except the developing limbs and several somites in the tail region. In this study, the global temporospatial pattern of PCD throughout early development of mouse embryos was discussed. It may provide the basis for further studies on its role in the morphogenesis of the embryo.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.569-578
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• 2004

The purpose of this study was to clarify the palatal arch length, width and height in the primary and permanent dentition. Samples were consisted of normal occlusions both in the primary dentition(50 males and 50 females) and in the permanent dentition(50 males and 50 females). With their upper plaster casts were used and through 3-dimensional laser scanning(3D Scanner, DS4060, LDI, U.S.A.), cloud data, polygonization, section curve and loft surface, fit and horizontal plane were based to measure the palatal arch length, width and height(Surfacer 10.0, Imageware, U.S.A.). T-tests were applied for the statistical analyze of the data. The results were as follows : 1. In the measurement values, the values of the male were higher than those of the female except primary anterior palatal height. There were not only statistically significant differences in anterior palatal width(p<0.05) and posterior palatal width(p<0.01) in primary dentition but palatal width(p<0.05), anterior palatal length(p<0.01), middle and posterior palatal length(p<0.05) in permanent dentition between male and female. 2. In the indices of palate, there were statistically significant differences in height-length index(p<0.05) and width-length index(p<0.01) between male and female in primary dentition. In permanent dentition, there was statistically difference between male and female. 3. In the measurement values, posterior palatal width was increased most greatly. Posterior palatal height, anterior palatal width and anterior palatal length were followed by descending order. On the other hand, anterior palatal height and posterior palatal length were decreased. 4. In the indices of palate, the height-length index, the width-length index and posterior height-width index were increased, but the others were decreased.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.50-62
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• 1989

This is clinicostatistical study of mandibular fractures. This study was based on a series of 677 patients with mandibular fracture during the period of 1982 to 1987. This results obtained were as follows : 1. In respect of incidence, there were high frequency in May and September, and in large city(63%). 2. The age frequency was the highest in the 20s-year old group (38.7%), and the ratio of male to female was 4.64 : 1. 3. The most common etiologic factor was blow(31.5%), but in children that was traffic accident followed by fall down. 4. The most common site of bone fractures was symphysis, followed by angle, condyle. In comparison of right and left sides, left side was more frequently involved(364 cases) than right side(257 cases). 5. The patients arrived in hospital immediately within 24 hours after accident were 62.9% of all, and 42.4% was arrived via private medical and dental clinic. 6. In respect of treatment, open reduction was 55.5% of all, closed reduction was 37.2%. In children, closed reduction was done in 50.6%.

• Journal of Korean Medical classics
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• v.18 no.2 s.29
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• pp.1-19
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• 2005

통과대명대저명의가(通過對明代著名醫家), 온보파창시자설기(溫補派創始者薛己)$(1487{\sim}1559)$적생애화의학사상(的生涯和醫學思想), 득출여하결론(得出如下結論): 설기생여의학세가(薛己生於醫學世家), 종소학습유학화의학(從小學習儒學和醫學), 기부사후(其父死後), 체부진입태의원성료의사(替父進入太醫院成了醫士), 지후선후역임태의원이목(之後先後歷任太醫院吏目), 남경태의원원판(南京太醫院院判), 원사등직(院使等職), 병어1540년(44세)기관회향(幷於1540年(44歲)棄官回鄕), 전심여치료환자여저술(專心於治療患者與著述). 설기적저작대부분내(薛己的著作大部分內) 용이의안형식서사(容以醫案形式書寫), 기내용포함내과(其內容包含內科), 외과(外科), 부산과(婦産科), 소아과(小兒科), 침구과(鍼灸科), 치과(齒科), 안과(眼科), 골과(骨科), 본초등(本草等). 기본인친(其本人親) 자저술적유이(自著述的有以)${\ulcorner}$내과적요(內科摘要)${\lrcorner}$위시약12종(爲始約12種), 교주적유이(校注的有以)${\ulcorner}$부인대전양방(婦人大全良方)${\lrcorner}$위시8종(爲始8種), 교감적의서약유6종(校勘的醫書約有6種), 공계대약(共計大約) 유26종지다(有26種之多). 설기수(薛己受)${\ulcorner}$내경(內經)${\lrcorner}$, ${\ulcorner}$난경(難經)${\lrcorner}$급장원소화금원사대가적영향교심(及張元素和金元四大家的影響較深). 재사대가중(在四大家中), 우기수동원화단계적영향최심(尤其受東垣和丹溪的影響最深). 차외(此外), 가지기수교주의서적영향역교대(可知其受校注醫書的影響亦較大), 기통과박람군서(其通過博覽群書), 대담실천(大膽實踐), 광수자료(廣收資料), 선우총결(善于總結), 최종성료일명의가(最終成了一名醫家). 설기수이동원(薛己受李東垣)${\ulcorner}$비위론(脾胃論)${\lrcorner}$적영향(的影響), 강조비위적중요성(强調脾胃的重要性), 병수차제출비통혈적이론(幷首次提出脾統血的理論) 기여이동원적학설부동지처시(其與李東垣的學說不同之處是), 재치료화쇠토약형허한증시(在治療火衰土弱型虛寒證時), 주장이보화생토지법내치료(主張以補火生土之法來治療), 인위비여신적생리작용호위관련(認爲脾與腎的生理作用互爲關聯), 비토화생정미(脾土化生精微), 이자양신여명문(以滋養腎與命門) 반과래(反過來), 신여명문역대위토기온후작용(腎與命門亦對緯土起溫煦作用); 이재병리방면(而在病理方面), 비토구허(脾土久虛), 가치신허(可致腎虛), 신허즉불능생토(腎虛則不能生土), 역가치비허(亦可致脾虛). 설기적극반대명대의가수금원지유풍(薛己積極反對明代醫家受金元之遺風), 이한양약공하(以寒凉藥攻下), 혹남용지백이강화(或濫用知柏以降火), 극벌생기적작법(克伐生氣的作法), 이주장용편온적약물진행조보(而主張用偏溫的藥物進行調補), 기상용적전인처방유보중익기탕(其常用的前人處方有補中益氣湯), 사물탕(四物湯), 사군자탕(四君子湯), 육군자탕(六君子湯), 독삼탕(獨蔘湯), 삼부탕(蔘附湯), 육미환(六味丸), 팔미환(八味丸), 신기환(腎氣丸), 회양탕(回陽湯), 당귀보혈탕등(當歸補血湯等).

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.491-498
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• 2021

In this study, the effective dose was measured using the PCXMC v2.0 program by examining the conditions used to set the diagnostic reference level for intraoral imaging recommended by the government, and the effect of the Al additive filter was confirmed. In oral imaging, the largest effective dose was calculated from the oral mucosa among 11 organs. The effect of the Al additive filter showed an excellent radiation reduction effect at 2mm rather than 1mm. In the case of children aged 5 years, the overall effective dose was calculated to be high in all 11 organs because they are more sensitive to radiation than adults. And as a result of evaluating the image quality according to the use of an additional filter during intraoral imaging, there was no significant difference in SNR and CNR changes compared to before the additional filter was used. Based on this study, it is thought that additional filter settings can be recommended for intraoral imaging.

• The korean journal of orthodontics
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• v.36 no.4
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• pp.284-294
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• 2006

Objective: Activating mutations in the fibroblast growth factor receptor-2 (FGFR2) have been shown to cause syndromic craniosynostosis such as Apert and Crouzon syndromes. The purpose of this pilot study was to investigate the resultant phenotypes induced by the two distinctive bone-targeted gene constructs of FGFR2, Pro253Arg and Cys278Phe, corresponding to human Apert and Crouzon syndromes respectively. Methods: Wild type and a transgenic mouse model with normal FGFR2 were used as controls to examine the validity of the microinjection. Micro-CT and morphometric analysis on the skull revealed the following results. Results: Both Apert and Crouzon mutants of FGFR2 induced fusion of calvarial sutures and anteroposteriorly constricted facial dimension, with anterior crossbite present only in Apert mice. Apert mice differed from Crouzon mice and transgenic mice with normal FGFR2 in the anterior cranial base flexure and calvarial flexure angle which implies a possible difference in the pathogenesis of the two mutations. In contrast, the transgenic mice with normal FGFR2 displayed normal craniofacial phenotype. Conclusion: Apert and Crouzon mutations appear to lead to genotype-specific phenotypes, possibly causing the distinctive sites and sequence of synostosis in the calvaria and cranial base. The exact function of the altered FGFR2 at each suture needs further investigation.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.21-25
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• 2004

In modern times, children's trauma is increasing every year because of car accidents and life environment changes. There is a limit to prevent traumatic damage for oral cavity organization. The fundamental data of trauma treatment and prevention will be presented through the survey and analysis of traumatic teeth damage. I examined 113 patients from Oct. 4th, 2000 to Feb. 27th, 2004 at Dept. of Children's Dental Clinic, Kangnung National University. The results are as follows. (1) The trauma frequency of male subjects is higher than that of female at a rate of 2.05:1. The average age is 5.27 for men and 5.27 for women. The highest percentage of trauma patients is among 2 year old children. It is 21.2%. (2) A patient survey was taken at a trauma treatment hospital. On the first day 34.4% of the patients had come to receive treatment of their first set of teeth. However, after a week, 38.8% of the patients had received treatment on their permanent teeth. (3) As a result of falling, 59% of patients needing treatment on their first set of teeth. 55.1% of patients is permanent teeth. As a result of bump against physical solid, 26.6% of patients is the first set of teeth and 26.5% of patients is permanent teeth. (4) Teeth damage happened at home. 42.1% were male. 35.1% were female. According to trauma, 59.4% of teeth damage happened at home. 28.6% of permanent teeth damage happened at school or kindergarten. (5) According to trauma, the number of teeth damaged was in the first set of teeth are as follows: 56.3%, one-31.3%, three or four-6.3% each. For permanent teeth: two-46.9%, one-28.6%, four over-16.3% and three-8.2%. Over four teeth is larger number for permanent teeth. (6) 56% of first set of teeth patients and 43.4% of permanent teeth patients were male. 56.8% of first set of teeth patients and 43.2% of permanent teeth were female. Trauma happened to both male and female frequently in the first set of teeth. (7) Most of the tooth damage which was in the first set of teeth and permanent teeth was done to the upper jaw. 75% of patients are the first set of teeth. 63.8% of patients are permanent teeth. Trauma is very high in the two mid teeth of the upper jaw. (8) According to trauma survey, 30.2% is from impulse. 28.0% is from crown fracture, 14.7% is from depression. 8.9% is from concussion. 7.1% is from full dislocation of a joint. 2.2% of patients are extrusion. 1.8% is from displacement. According to teeth damage trauma, 35.8% is pulse in the first set of teeth. The breaking of the crown of a tooth happened a lot in permanent teeth. (9) According to data, 43.2% of teeth damage in the first set of teeth goes without treatment. In permanent teeth, it is 38.9%. After treatment, 22.0% of first set of teeth treatment requires a dental pulp treatment. In permanent teeth, which is used for temporary acid etching resin restoration.

• Journal of Korean society of Dental Hygiene
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• v.8 no.2
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• pp.39-51
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• 2008

The research was conducted to 100 child patients selected by random sampling, which got a Dentocult-SM test in the first visit and then was being continuously managed, out of child patients of a pediatric clinic located in Gyeonggi-do. The period of there search is one year from June 2007 to May 2008, Using Dentocult-SM test, we analyzed the correlation between the distribution of dental plaque, a streptococcus mutans in saliva and condition of dental caries cavity in the teeth of child patients, then we measured the distribution of a streptococcusmutans. According to SM score, we applied incremental oral heath care for child patients to clinical and obtained the following results, 1. In terms of the age of child patients in research, the number of 3 years old patients was 29(lst ranked), the number of 2 years old patients was 28(2nd ranked). 2. The result of SM score showed that female child patients(52.0%) was higher than male ones in negative, male child patients(52.0%) was higher than female ones in mild, female child patients(68.2%) was higher than male ones in moderate, male child patients(57.1%) was higher than female ones in severe. 3. At the first visit, the SM score showed statistically remarkable difference between dt and dmft. We can also confirm the average of severe is the highest. 4. At the second visit, the SM score showed statistically remarkable difference among dt, ft, and dmft index We can also confirm the average of severe is the highest. 5. At the third visit, The SM score showed statistically remarkable difference among dt, ft, and dmft index We can also confirm the average of severe is the highest. 6. The comparison of dmft index differences to SM score showed statistically no remarkable difference in incremental oral heath care for negative and mild, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences in moderate and severe. 7. The comparison of dt index differences to SM score showed statistically no remarkable difference in incremental oral heath care for negative, mild, and moderate, In addition to that, we can con firm that the incremental oral heath care makes statistically remarkable differences in severe. 8. The comparison of mt index differences to SM score showed statistically no remarkable difference in incremental oral heath care for mild and moderate, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences m severe. 9. The comparison of ft index differences to SM score showed statistically no remarkable difference in incremental oral heath care for mild, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences in negative, moderate, and severe. 10. According to the comparison of dmft index to the age, the 4 years old patients showed the highest number(5.50 in the first visit and 6,08 in the second one). In the third visit, the 6 years old patients showed the highest number(7.00). By the above results, we can find that the incremental oral heath care by SM score makes the results of oral care better. Therefore, the improvement or maintenance in oral health of child patients needs continuing personal oral health management and regular systematic management focused on prevention by the specialist.