시판 청량음료 시음 후의 마뇨산 배설에 관한 실험적 연구

장성훈,김청식,김준식 건국대학교 의과학연구소 1999 건국의과학학술지 Vol.9 No.-

In this study, we measured the urinary excretion of the hippuric acid after ingestion of several kinds of common soft drinks. The urinary hippuric acid has been known as a sensitive and specific biomarker of toluene exposure in workplace. But it has not been known exactly that drinking some kinds of soft drinks can increase urinary hippuric acid significantly even in usual dosage. These phenomena surely can invoke problems in interpretation of urinary hippuric acid at the regular health check up of the workers exposed to toluene. We recruited 140 healthy volunteers(medical school students) and surveyed their diet history, medication, smoking and drinking habit before experiment. The persons who had eaten some kinds of food or drinks which were including benzoic acid were excluded and the rest 122 were divided into 2 groups. The Experimental group(n=88) drank the soft drinks which contained benzoic acid, and the control group(n=34) drank the soft drinks which contained not. We checked the excretion of urinary hippuric acid in 1.5hr and 3hr after ingestion of the drinks in each group. The measurement of urinary hippuric acid was performed by using high performance liquid chromatography(HPLC). The results were as follows: 1. The mean age(year) was 23.3±1.4 in experimental group, and 23.5±2.4 in control group; the number of female was 13(14.8%) and 4(11.8%) in each group. 2. The geometric mean of urinary hippuric acid before drinking soft drinks was 0.24, and 0.21g/l in experimental and control group(p=0.426). In 1.5 hour after ingestion of the drinks, the geometric mean increased 1.14g/l in experimental group, and 0.17g/l in control group, which was significantly different after adjusting the urinary hippuric acid before drinking(p<0.01). By addition some other covariates(sex, smoking in amount) in the model, the result was not changed(p<0.01). In 3.0 hour after ingestion, the geometric mean was 0.32 and 0.16g/l in each group, even the difference was much smaller than that of 1.5 hour after drinking, which was statistically different after adjusting the urinary hippuric acid of before drinking(p<0.01), sex and smoking additionally(p<0.01). 3. The mean increasement of urinary hippuric acid after 1.5 hour(Diff 1) after ingestion was 0.83 in experimental group, which was significantly different from that of control group(-0.06, p<0.01). Diff 2(the increasement after 3.0 hour) was also different from each other(p<0.01). 4. We used 7 different kinds of soft drinks in experimental group. The increasement after drinking them was different from 0.57 to 1.05g/l after 1.5 hour, from -0.08 to 0.08g/l after 3.0 hour, but statistically not significant in each other(p=0.146, p=0.849 in sequence). We concluded that the soft drinks which contain benzoic acid could increase the urinary hippuric acid excretion significantly, even over 1.0g/l without toluene exposure. It seems to be needed that check the diet and drink(at least 3.0 hour before collect the urine) history is essential in interpretation of urinary hippuric acid concentration.

思春期前 兒童의 正常 鼻腔 通氣度에 관한 硏究

서정훈,장영일,양원식,남동석 대한치과교정학회 1992 대한치과교정학회지 Vol.22 No.1

This study was designed to analyze normal nasal respiratory resistance in prepubertal children. The subjects consisted of 30 prepubertal children(male:15, female:15).The mean age was 11.4 years in male children and 11.5 years in female children. The results were as follows: 1.The normal nasal respiratory patency was lower than the normal values from RION corp. 2.The normal nasal respiratory airflow rates showed no sexual differences. And there were no differences between inspiration and expiration. 3.Before and after use of nasal decongestants, there were no significant differences of normal nasal respiratory airflow rates and after the administration of nasal decongestants, nasal respiratory patency manifested lower variability. 4.The normal nasal respiratory resistance without nasal decongestants at 150 Pascal in inspiration was 0.30 Pa/cm³/sec(±0.07) and peak nasal inspiratory airflow rate was 1016.83cm³/sec(±223.89). 5.The normal nasal respiratory resistance with nasal decongestant at 150 Pascal in inspiration was 0.25 Pa/cm³/sec(±0.05) and peak nasal inspiratory airflow rate was 1148.33 cm³/sec(±234.29).

재생 브라켓의 전단접착강도에 관한 비교 연구

서정훈,최은아 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.4

본 연구는 열을 이용한 금속 브라켓의 재생 처리시, 기저부 형태와 브라켓 재생 방법에 따른 전단접착강도 및 브라켓 탈락 양상을 비교하고자 시행되었다. 교정 치료를 위해 발거된 건전한 소구치 252개를 수집하고, Type I, Type II, Type III 스탠다드 브라켓을 각각 재생 방법에 따라 네 군으로 나누어 준비된 소구치에 접착하고, Instron Universal Testing Machine(Model 4466)으로 전단접착강도를 측정하였으며, 브라켓의 타락 양상을 관찰하고 브라켓 기저부의 주사전자현미경 소견을 관찰하였다. SP SS 통계처리 프로그램을 이용하여 일원분산분석(oneway ANOVA), Scheffe`s multiple range test를 실시하여 다음과 같은 결론을 얻었다. 1. 브라켓 기저부 형태에 따른 전단접착강도는 유의차가 있었으며(P<0.001), 그 크기는 Type III(round indentation, micro-etched base), Type I(foil-mesh base), Type II(grooved integral base, micro-etched)의 순이었다. 2. 재생 방법에 따른 전단접착강도는, Type I, Type II 브라켓에서는 Big Jane에 1분간 처리시 우수한 결과를 보였고(p<0.05), Type III 브라켓에서는 각 군간 유의한 차이를 보이지 않았다.(p>0.05). 3. Type I, Type II 브라켓은 기저부-레진 계면에서 가장 높은 빈도로 탈락하였고, Type III 브라켓에서는 레진의 절반가량이 치면에 잔존하는 탈락 양상이 가장 많았다. 4. 탈락 양상에 따라 탈락시의 전단접착강도가 유의성 있는 차이를 보였는데(p<0.05), 브라켓 탈락시 접착제의 절반가량이 치면에 잔존하는 경우 전단접착경우가 가장 큰 것으로 나타났다. 5. 브라켓 재생 후 기저부에 남아 있는 접착제는 전단접착강도의 감소에 영향을 미치지 않았다. This study was undertaken to compare the bond strength and the fracture site of new and recycled brackets according to the base design. 252 sound premolars extracted for orthodontic treatment were collected, and Type I, Type II, Type III brackets were divided into four groups by recycling method. Each bracket was then bonded to an extracted premolar. Instron Universal Testing Machine(model 4466) was used to measure the shear bond strength, and the surface of the recycled brackets were viewed in SEM. For the analysis of the results, one way ANOVA and Scheffe`s multiple range test was executed using the SPSSWIN program. 1. The shear bond strength showed statistically significant difference according to the bracket base design (P<0.001). Type III bracket(round indentation base, micro-etched) showed the highest bond strength, Type I bracket(foil-mesh base) was second, and Type II bracket(grooved integral base, micro-etched) was last. 2. The effect of recycling on the bond strength was different according to bracket type. The shear bond strength of Type I, Type II brackets showed the smallist reduction when treated for 1 minute in Big Jane(p<0.05), but the shear bond strength of Type III brackets showed no statistically significant difference according to recycling method(p>0.05). 3. In Type I, Type II brackets, frequent fracture site was bracket-resin interface, but in Type III brackets, about half of the resin was retained on the tooth surface frequently. 4. The shear bond strength was highest when about half of the resin was retained on the tooth surface(p<0.05). 5. The resin remnant on the bracket base after recycling had no effect on the shear bond strength.

산부식시간이 법랑질 표면 부식형태와 교정장치의 전단접착강도에 미치는 영향에 관한 연구

서정훈,장영일,양원식,남동석 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.5

본 연구의 목적은 법랑질 표면에 대한 산부식시간의 차이가 법랑질 표면의 부식형태, 교정장치의 전단접착강도 및 탈락 양상에 미치는 영향을 알아보는 것이다. 교정치료를 위해 발거된 하악 소구치의 법랑질을 37%의 인산 용액을 이용하여 동일한 방법으로 각각 5, 10, 15, 30, 45, 60, 90, 120초동안 부식시킨후 법랑질 표면을 주사전자현미경으로 관찰하고, 교정장치를 접착한 후 Instron universal testing machine을 이용하여 전단접착강도를 측정하고 교정장치의 탈락양상을 관찰하여 다음과 같은 결론을 얻었다. 1. 산부식시간을 5-120초 범위에서 변화시켜도 교정장치의 전단접착강도는 통계학적으로 유의성 있는 차이가 없었다(p<0.05). 2. 산부식시간에 따른 교정장치의 탈락양상은 15초이하 부식군에서는 접착제/법랑질 경계부 탈락이 상대적으로 많았으나, 30초 이상 부식군에서는 접착제/교정장치 경계부 탈락이 많았다. 3. 법랑질 표면의 부식형태는 매우 다양하였으며 동일한 법랑질 표면에서도 여러 가지 형태의 부식 소견이 관찰되었다. 또한 법랑질 부식형태와 교정장치의 접착강도 사이에 연관성을 발견할 수 없었다. 4. 본 연구의 결과는 실험적 조건에서는 부식시간을 5초로 단축하여도 임상적으로 유용한 접착강도를 얻을 수 있음을 보여주고 있다. 그러나, 15초 이하 부식군에서 나타난 탈락양상에 대해서는 더 많은 연구가 이루어져야 할 것으로 여겨진다. The purpose of this in vitro study was to evaluate the effects of different acid etching times on th enamel surface morphology, shear bond strength and debonding failure mode of orthodontic attachment. Ninety six extracted human mandibular premolars were divided into eight groups of twelve teeth. The buccal surfaces were etched with 37% phosphoric acid for 5, 10, 15, 30, 45, 60, 90 and 120 seconds, respectively. Two teeth from each group were used for scanning electron microscope examination. On the etched buccal surfaces of remaining teeth, orthodontic attachments(lingual buttons)were bonded with light cured orthodontic adhesive. Twenty four hours after bonding, a Instron universal testing machine was used to determine shear bond strength of orthodontic attachment to enamel. After debonding, bases of orthodontic attachments and enamel surfaces were examined under stereoscopic microscope to determine failure mode. Statistical analysis of the data was carried out with on way ANOVA and Duncan's multiple range test. The results were as follows; 1. There was no statistically significant difference in shear bond strengths between the various etching times(p<0.05). 2. The failure modes of orthodontic attachments had some differences. In 5, 10 and 15 seconds etching groups, the percentage of adhesive/enamel interface failure was higher than that of adhesive/attachment interface failure. On the contrary, in 30, 45, 60, 90 and 120 seconds etching groups, the results were reversed. 3. The etching patterns of enamel surfaces had a great variation. So, we could not find any correlation between etching pattern and bond strength. 4. The findings in this study indicate that in vitro reduction of the etching time to 5 seconds maintains clinically acceptable bond strength. However, further study is required to determine the cause of failure mode in 5, 10 and 15 seconds groups.

頭部放射線計側寫眞에 依한 脣, 口蓋裂者의 顎顔面 成長에 關한 硏究

徐廷勳,玄成旭 대한치과교정학회 1982 대한치과교정학회지 Vol.12 No.2

A cephalometric radiographic cross sectional comparative study was undertaken to investigate craniofacial growth in cleft lip and palate individuals. The material for this study consisted of 43 subjects with operated cleft lip and palate. (29 males, 14 females). The range of age was from 6 years to 12 years. The roentgenocephalometric values of cleft individuals were compared with values of normal individuals reported by Lee. 28) The following conclusions were obtained; 1) The pattern of cranial base of the cleft subjects was almost the same as that previously reported for the normal individuals. 2) Anterio-posterior length of the mandible did not show any significant difference but in the cleft subjects, that of the males was larger than that of the females. 3) The maxilla of the cleft subjects was very retruded and showed very concave profile. 4) Gonial angle of the cleft subjects was very high, especially in the female clefts. 5) The height of ramus was very poor in the cleft subjects. 6) The facial length was almost the same, but the facial depth of the cleft subjects was smaller than that of the normal individuals. 7) Maxillary and mandibular incisors were severely retroclined. 8) The range of values in the cleft subjects was very variable and th female clefts showed more distured growth than the male clefts.

부정교합과 교정치료에 대한 인식변화에 관한 연구

서정훈,김태우,이신재 대한치과교정학회 1994 대한치과교정학회지 Vol.24 No.1

In this study, in order to survey the effect on public recognition in malocclusion and orthodontic treatment by brochures made by Korean orthodontic association, sample were divided into control and experimental group and a questionnaire was inguired and the results were as follows : 1. In the experimental group, frequency of recognition for the need of orthodontic treatment was high, and this indicates dental health behavior and recognition can be inspired by adequate giving of information. 2. Between the control and the experimental group, patterns of the negative opinion was different, and especially the demand for specific orthodontic treatment can be influenced by the content of brochures. 3. The brochures used in this study can call attention to develope the orthodontic aspect for the malocclusion, hereafter more systemic and active measures for development of public dental behavior and recognition should be needed.

좌전하행지 관동맥 개구부위의 망사형의 관(Slotted Tube)스텐트와 나선형 코일(Coil)스텐트 삽입후 단기 및 장기 암상 경과의 비교

박훈기,박성욱,이일수,이상곤,김진우,이근,정상식,이철환,홍명기,김재중,박승정 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.6

Ⅱ급 1류 부정교합에서 bionator의 치료효과에 관한 유한요소법적 연구

안석준,서정훈 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.2

본 연구의 목적은 Ⅱ급 1류 부정교합에서 BIONATOR를 사용한 환자의 치료 전후 두부방사선계측사진에 유한 요소법을 적용하여 나타난 변화를 각 요소별로 나타내며, 이러한 변화와 치료에 영향을 미치는 인자들 간의 연관성을 살펴보는데 있다. 앵글 Ⅱ급 1류 부정교합을 가진 73명을 치료결과가 양호한 군(1군)과 치료결과가 불량한 군(2군)으로 나눈 후 각각의 치료효과에 대한 유한요소분석을 실시한 후 성별간, 치료결과군간 및 치료시작시기와의 유의성을 검증하였으며(SAS ANOVA, P<0.05), 치료기간과의 상관관계를 살펴보았다. 또한 치료결과가 다르게 나오는 이유를 보고자 두개저의 길이(Ba-N)를 기준으로 1군에서 2군으로 유한요소분석을 실시하여 다음의 결과를 얻을 수 있었다. 1. 치료효과와 성별간, 치료결과군간 사이에 유의한 차이가 없었다 (p>0.05). 2. 치료시작 연령과 치료효과 사이에 유의한 차이가 없었다(p>0.05). 3. 치료효과와 치료기간 사이에서는 상악체, 상악절치, 하악절치, 전안면, 전상안면, 전하안면, 하악지 등을 대표하는 유한요소에서 유의한 차이(p<0.05)가 있었으나, 상관관계는 높지 않았다. 4. 유한요소 분석 결과 골격보다는 치아를 대표하는 요소의 변화가 더 컸다. 특히 상악절치의 위치, 하악절치의 위치, overbite 등을 나타내는 요소의 변화를 뚜렷하게 관찰할 수 있었다. 5. 치료결과가 다르게 나타나는 이유를 두개저(Ba-N)길이를 중심으로 유한요소로 분석한 결과 두군사이에 골격 및 차아의 위치에서 상당한 차이가 있음을 관찰할 수 있었다. 치료결과가 나쁜 군에서 상악의 후하방 회전, 하악의 후방위치, 상악전치의 상대적인 설측경사, 하악절치의 상대적인 순측경사 등을 관찰할 수 있었다. The purpose of this study was to evaluate treatment effects of bionator in ClassⅡ division 1 malocclusion by FEM(Finite Element Method). The 73 subjects were classified into good result group and poor result group in reference to posttreatment molar relation, posttreatment overbite and overject, posttreatment profile, and relapse. Pretreatment and posttreatment lateral cephalograms were taken and FEM was performed. The results were as follow; 1. There was no statistical significance in treatment changes between the sexes, and between the treatment result groups. 2. Treatment changes were not significantly different among the age groups. 3. The effect of treatment period groups on skeletal and dentoalveolar changes were analyzed using ANOVA. Body of maxilla, upper incisor, anterior face, ramus, upper anterior face, lower anterior face and treatment effect were correlated with the treatment period, but correlation coefficients were low. 4. The results of present investigation confirm that ClassⅡ bionator can assist in the correction of Class Ⅱ division 1 malocclusion, mainly due to dentoalveolar changes. 5. There is significant difference in skeletal and dentoalveolar pattern between good result group and poor result group. In poor result group, maxilla was relatively downward and backward rotated, mandible was relatively backward rotated, upper incisor was in relatively lingual position, lower incisor was in relatively labial position.

일부 농약 취급 근로자들의 성호르몬 상태

이원진,김청식,김형수,이창훈,김진석 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objective : This study was carried out to determine the effects of occupational pesticides exposure on the level of serum Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), testosterone in male workers. Methods : Twenty-two male workers exposed to pesticides were compared with twenty-eight male workers at same factory who were not exposed to pesticides. The selected variables for studying reproductive hormones were LH, FSH and testosterone. As part of the baseline health status, subjects were asked medical history. Results : There were no statistically significant differences on the level of LH, FSH, testosterone between the exposed and non-exposed group. Also the level of sex hormones were not significant difference with each department in exposed group. And the level of LH, FSH positively correlated with age. Conclusions : These results indicate that there are no alterations in LH, FSH, testosterone at workers exposed to pesticides. But our findings are highly preliminary because of a small sample size. Thus it calls for furthur investigation of the hormonal effects at workers exposed to pesticides.

이부기형을 동반한 부교교합에서의 이부골성형술의 응용

장영일,서정훈,남동석,이하진 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.3

턱은 인간의 성격을 나타내는 요소의 하나로 적절하게 돌출된 턱은 심미적인 안모를 위해 대단히 중요하다. 이부골성형술은 턱의 형태재형성을 목적으로 하며 이를 통해 고정치료 목적의 하나인 안모의 심미성 향상에 기여할 수 있다. 이부골성형술은 수직, 수평적으로 턱의 크기를 확대시키는 축조이부골성형술과 축소시키는 축소이부골성형술로 나눌수 있으며 그활용하는 예는 다음과 같다. 1. 후퇴된 턱의 전진 2. 전방 돌출된 턱의 후퇴 3. 수직고경의 조절 4. 비대칭의 개선 The chin is one of the factors which express human character, and appropriately protruding chin is very important to harmonious profile, the purpose of genioplasty is to reshape the chin and improve the facial esthetics which is one of the purposes of orthodontic treatment, It can be classified as augmentation genioplasty which enlarge the chin vertico-horizontally and reduction genioplasty whcih smallen it. The examples to apply this procedure are as follows. 1. advancement of retruded chin 2. reduction of chin prominence 3. control of chin vertical dimension 4. correction of asymmetry