• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.42 no.5
• /
• pp.251-258
• /
• 2016

Objectives: The aim of this retrospective study was to investigate factors associated with increased difficulty in the surgical extraction of impacted lower third molars and to improve identification of difficult cases. Materials and Methods: A total of 680 patients who required 762 surgical extractions of impacted lower third molars from 2009 to 2014 were enrolled in the study. Demographic factors, clinical factors, radiographic factors, surgical extraction difficulty, and presumed causes of difficulty were collected. Data were statistically analyzed using IBM SPSS Statistics version 23. Results: Age, sex, depth of impaction, and blurred radiographic image influenced difficulty in surgical extraction. The position of the impacted tooth influenced surgical difficulty, especially when it was accompanied by other factors. Conclusion: It is challenging to design a reliable and practical instrument to predict difficulty in surgical extraction of impacted lower third molars. To identify very difficult cases, root investigation using computed tomography is advised when impacted tooth position suggests difficult extraction.

• The korean journal of orthodontics
• /
• v.18 no.1 s.25
• /
• pp.79-88
• /
• 1988

The purpose of this study was to investigate the factors which might be related to mandibular third molar eruption and to predict the possibility of whether or not it will be erupted. The material of this study was lateral cephalometric radiograms, pantomograms and dental casts obtained from 70 patients (19 males, 51 females) ranging in age from 18.0 to 32.1 years. They were devided into erupted group and impacted group of mandibular third molars. For the comparison of each group, a total of 20 measurement items were employed and the data were analyzed by means of computer statistical method. As a result of this study, the following conclusion can be made; 1. The longer mandibular body length and narrower mandibular ramus width, the higher eruption tendency of the lower third molar, but the degree of genial angle was not related to mandibular third molar eruption. 2. The lower percentage of posterior mandibular body height to anterior mandibular body height, the higher eruption tendency of the lower third molar. 3. The total tooth size, including the lower second molar, appeared to be larger in the impacted group than in the erupted group of the lower third molar. 4. The arch length discrepancy of the impacted group was more severe in contrast with the erupted group of the lower third molar.

• Journal of the Korean Society of Costume
• /
• v.51 no.6
• /
• pp.167-176
• /
• 2001

This study analyzes characterization and classification of body types of Mongolian women aged 18∼39 ages. The anthropometric measurements of the research subjects come up to a total of 23 items and are summarized as follows : 1. As the results of comparative analysis of the body measurements by age group, 16 items show a significant difference except shoulder height, thigh girth, neck base girth, back length shoulder length, sleeve length and weight. Both age group are considered to be of average weight but 25 to 39 age group were slightly greater than that of the 18 to 24 age group. 2. As the results of factor analysis, 4 factors such as the first factor on the obesity of body, the second factor on the vertical size of body, the third factor on the back length, the forth factor on the shoulder width and neck base girth were extracted. 3. As the results of classification based on the duster analysis, the body types were classified into 3 types in each age group. In each age group the most frequent body type is average stature and slightly thin type.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.18 no.1
• /
• pp.153-163
• /
• 1988

The purpose of this study is to investigate on the clinical and radiographic patterns of cystogenic ameloblastoma of the jaws. The author studied 64 cases of cystogenic ameloblastoma with regard to age, sex distribution, the site of the lesion and several radiographic features. The results were as follows: 1. The average age was found to be 23.0 years, with a range of 4 to 56 years. The incidence was highest in the second and third decades (72%) and total 64 cases consists of 36 males and 28 females. 2. Fifty-nine cases were found in mandible and 5 cases in maxilla. 3. The specific site distribution was found to be 57.8% ramus, coronoid process and condyle, 34.4% premolar-molar region, and 7.8% were located in mandibular symphysis bilaterally. 4. From the total 64 cases, 28 (44%) were associated with an impacted tooth, especially mandibular second and third molar, 36(52%) failed to show any association with tooth impaction. It was found that the average age for impaction-associated tumors was 19.8 years whereas lesions without impaction occurred at an average age of 25.6 years, which was statistically significant. 5. Fifty-three(82%) cases showed unilocular radiolucencies, eleven (17%) cases showed multilocular radiolucencies. It was found that the average age for unilocular lesions was 22.3 years whereas lesions showing multilocularity occurred at an average age of 26.4 years, which was not statistically significant. 6. Of the 21 patients who had been followed for more than 2 years, only 4 patients treated by enucleation or curettage recurred (19% recurrence).

• Speech Sciences
• /
• v.12 no.2
• /
• pp.139-149
• /
• 2005

The purpose of this study was to propose a preliminary norm for 'Korean-Test of Articulation for Children(K-TAC)'. The K-TAC was designed to test 19 Korean consonants in various phonetic contexts through 37 words. We collected the data of 220 normally developing children aged 2;6(years;months) to 6;5. We analyzed the mean percentage of consonants correct and the age of acquisition for K-TAC. The results were as follows: first, The mean percentage was over 60% at late 2 years of age, over 80% at th age of 3, and over 90% after the age of 4. There were significant differences among age groups. Second, based on the criterion of correct production by 75% of children, Korean children acquired stops and nasals except for SF velars, glottal fricative, SF liquid and affricates by late 2 or 3 years of age. After that they acquired SF velars at the age of 4 and SI liquid at the age of 5. However, they could not acquire alveolar fricatives by the age of late 6. Third, if the distorted sounds were scored as correct, they acquired SI liquid at 4 years of age and alveolar fricatives at 5 years of age.

• Journal of the Korean Home Economics Association
• /
• v.33 no.6
• /
• pp.225-244
• /
• 1995

The purpose of this study is to see difference based on age, sex, sociometric ststus for perceived competence of children and difference about perception of responsibilities degree of parents of these children. the content of study as follows. 1. How is the difference about perceived competence of children based on age, sex, sociometric status. 2. How is the difference about perception of responsibilities of children based on age, sex, sociometric status. 3. How is the relationship between father and mother. The subject of this study is children and their parents of 126 persons of the third grade, sixth grade of S elementary school, the second grade of S middle school, the second grade of S girls' middle school which are located in Pusan city. This study used a peer nomination among sociometric assesment method as sociolity assessment means, self-perception profile for children of Harter(1985) as perceived competence assessment means of children and used self-perception profile for children which amends fits for parents. the collected data are managed by SPSS/PC+ program. We analyze three-way ANOVA to verify study question No, one, two, analyze t-verification and Pearson's product moment correlations to verify study question No. three. The result of this study as follows. First, in investigating difference about perceived compretence of children based on age, sex, sociometric status, we can see that children perceive high, self-ability for low ages. Also, boys than girls, popular children than rejected children, neglected children perceive high self-ability. Second, in investigating difference about perception of responsibilities of children based on age, sex, sociometric status, we can see that mother perceive responsibilities in learning sphere, exercise sphere, the whole self-value sphere and father perceive responsibility only in social sphere. Third, in investigating relation between perception of responsibilities of father and mother, this shows that difference between perception of responsibilities of father and mother is not showed ane have (+) interrelation of r=.46(P<.001) between perception of responsibilities of father and perception of responsibilities of mother.

• Korean Journal of Agricultural Science
• /
• v.44 no.4
• /
• pp.519-524
• /
• 2017

The present study investigated the impacts of mating age of gilts (A1, < 230 days; A2, 230 - 249 days and A3, $250{\leq}days$) on reproductive performance and litter size of sows at farrowing to weaning. A total of 102 crossbred gilts ($Yorkshire{\times}Landrace$; average days old, 90 days) were purchased from a commercial breeding company. After identification of third estrus, the gilts were artificially inseminated using semen of Duroc boars. Pregnant pigs were allotted to one of three groups including A1, A2, and A3. Experimental diets and water were fed ad libitum during each experimental period which included the first, second, and third parities. Backfat thickness (BFT) of sows was higher in A3 at farrowing in the first parity than in others. At weaning time in the second parity, sows in A3 group showed a numerically higher BFT than those in A1. There was no effect of mating age on the total number of piglets born and total weaned piglets. There was a tendency to decrease the wean-to estrus-interval in the first parity as age increased at mating. Results obtained in the present study indicate that the first mating age does not affect the subsequent parites' reproductive performance; however, weaned to estrus interval tended to decrease in A2 at the first parity.

• Human Ecology Research
• /
• v.59 no.2
• /
• pp.233-243
• /
• 2021

This study examined the longitudinal effects of media usage by early school-age children and of maternal parenting stress on children's school adjustment. The study focused on the mediating effect of executive function difficulty. Longitudinal data to examine the hypothetical model were drawn from the eighth (2015) through tenth (2017) waves of the Panel Study of Korean Children (PSKC) collected by the Korea Institute of Child Care and Education (KICCE). A total of 581 children (293 boys and 288 girls) and their mothers were included. Confirmatory factor analysis, structural equation model, and bootstrapping analysis were applied using SPSS 25.0 and Amos 26.0. The results are as follows. First, no significant correlation was found between early school-age children's media usage and maternal parenting stress. Second, neither media usage by early school-age children nor maternal parenting stress were found to directly affect children's school adjustment. Third, media usage by early school-age children and maternal parenting stress were shown to indirectly affect children's school adjustment via executive function difficulties. In other words, higher levels of media usage by early school-age children and maternal parenting stress during the first grade lead to greater executive function difficulties after a year, which, in turn, lead to a lower level of school adjustment in the third grade. This study indicates the need to develop practical support for the psychological wellbeing of mothers while they are performing their role as a parent and for children in maintaining suitable levels of media usage during early childhood.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.17 no.4
• /
• pp.396-406
• /
• 1995

This is a clinical and retrospective study who sustained a total of 306 maxillofacial bone fracture and who were treated in our department between 1990-1994. This results were obtained as follows : 1. The ratio of men to women was 3.2 : 1. 2. The age frequency was the highest in the third decade(35%). That of man was the highest in the third decade but that of women in the fourth decade. 3. In respect of incidence, the number of patients has not been increased year after year. There were the highest frequency in September and the lowest frequency in January. 4. The most frequent cause of facial bone fracture was fall down(40.2%), traffic accident(28.1%), fist blow(20.9%), industrial accident(6.2%) and others in order. 5. The most common location of facial bone fracture was mandible(69%), maxillar with zygoma and zygoma in order of frequency. 6. The age frequency of mandible was the third decade(36.5%), the fourth decade(23.2%) and the fourth decade(22.2%) and the fifth decade(15.6%) in order. 7. In respect of incidence of associated injuries, the ratio of absence to presence was 0.7 : 1. 8. In 306 patients of facial bone fracture, the frequency of associated injuries was laceration, extrimities, chest in order.

• The Korean Journal of Community Living Science
• /
• v.16 no.3
• /
• pp.75-85
• /
• 2005

This study was performed to clarify which variables affected a mother‘s empathic behavior shown in a mother-child play session. Mother’s empathy was videotaped and recorded during mother-child twenty minute play sessions. The variables considered in the research were the mother‘s parenting stress, age and education level, and the child’s sex and birth order. Twenty four mothers volunteered to participate in this study. The age of their children was restricted to 5 years. The results were as follows; First, mothers were verbally more accepting to their second or third child, and allowed their second of third child to lead more than their first child. And older mothers were more likely to accept their children's lead. Seconds, the mothers' parenting stress for acceptance of their children and stress of depression were higher in college graduate mothers than high school graduate mothers. Third, the mother's empathy and level of parenting stress did not show any significant relationships.