• 대한치과교정학회지
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• 제19권3호
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• pp.99-111
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• 1989

To study the sexual maturity at puberty and interrelation between pubertal growth peak and sexual maturity, 68 malocclusions (female 44, male 24) were longitudinally studied for 4 years and cross-sectional samples of 210 malocclusions were studied together. The pubertal growth peak was determined by stature increment and sexual maturity was studied using developmental stages of pubic hair and breast, menarche in female and those of pubic hair in male. The following results were obtained. 1. Mean age at menarche was 12.8 years and it was 11.8 months later than PHV. 2. At pubertal growth peak, developmental stage 2 (54.2%) and 3 (29.2%) of pubic hair were most in male, and stage 1 (72.7%) and 2 (20.5%) were most in female. 3. At pubertal growth peak, the developmental stage 2 (50%) of breast was most and the stage 3 (43.2%) was next. 4. In interrelation between skeletal growth and sexual maturity, PHV had most high correlation with menarche and stage 3 of breast, and menarche had most high correlation with stage 3 of breast. 5. Appearance of remarkable sexual maturity suggested that the PHV was passed already.

• 대한치과교정학회지
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• 제19권3호
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• pp.123-133
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• 1989

To predict the pubertal growth peak in stature and study the skeletal maturity degree using hand-wrist radiograph, the author used the 70 malocclusions (male 24, female 46). After longitudinal measurement of stature and skeletal maturity indicators of hand-wrist radiographs were taken during 4 years, the rsults were as follows. 1) The pubertal growth peak in stature occurred mainly at SMI 6-7 (56.5%) in female, SMI 5-6 (37.5%), 6-7 (37.5%) in male (Table 5). 2) It was suggested that the pubertal growth peak in stature was already passed, if SMI 8 occurred. 3) Ages of SMI in female were about 2 years earlier than those of SMI in male, and the sexual difference was gradually decreased in puberty. 4) Duration of SMI was longest at SMI 6-7 in both sex and the mean was 8.5 months. After this stage, the velocity of skeletal maturity in female was decreased than in male. 5) The correlation coefficient between each SMI and pubertal growth peak was very high (Table 8).

• 대한치과교정학회지
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• 제15권2호
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• pp.197-209
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• 1985

To investigate the relationship between the pubertal spurt in body height and bone maturity of the hand-and-wrist in normal occlusion, the author X-rayed the hand-and-wrists of 1,141 students (male 614, female 527) and assessed their bone maturity. In this study, eleven skeletal stages were selected. The bones used to determine skeletal maturity were the ulnar sesamoid of the metacarpophalangeal joint of the first finger, the epiphyses of the proximal, middle, distal phalanges of the third finger, and middle phalanx of the fifth finger, and distal epiphysis of the radius. From the longitudinal data for height, an assessment was made of the change in growth velocity. The pubertal growth stage was divided into onset and peak height velocity phases. The results were as follows; 1. The onset of the pubertal growth was between the $PP_3=\;and\;MP_3=$ stage for boys, and between the $MP_3=\;and\;MP_5=$ stage for girls; the mean age of onset was 10.6 years for boys and 9.0 years for girls. 2. The peak height velocity was between the S and $MP_{3_{cap}}$ stage for boys, and between the $MP_{3_{cap}}$ and $MP_{5_{cap}}$ stage for girls; the mom age of peak height velocity was 12.5 years for boys and 10.9 years for girls. 3. As the stages of bone maturity progressed from $DP_{3u},\;to\;PP_{3u},\;MP_{3u}$, Ru, the peak height velocity had been reached, and the growth rate retarded, therefore the approach to full physical maturity was attained. 4. The evidence for the period of onset, peak height velocity and bone maturation suggested that girls were in advance of boys. During the latter part of pubertal growth, the rate of boys' bone maturation was faster than that of girls'.

• 대한치과교정학회지
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• 제52권2호
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• pp.112-122
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• 2022

Objective: This study aimed to present and evaluate a new deep learning model for determining cervical vertebral maturation (CVM) degree and growth spurts by analyzing lateral cephalometric radiographs. Methods: The study sample included 890 cephalograms. The images were classified into six cervical stages independently by two orthodontists. The images were also categorized into three degrees on the basis of the growth spurt: pre-pubertal, growth spurt, and post-pubertal. Subsequently, the samples were fed to a transfer learning model implemented using the Python programming language and PyTorch library. In the last step, the test set of cephalograms was randomly coded and provided to two new orthodontists in order to compare their diagnosis to the artificial intelligence (AI) model's performance using weighted kappa and Cohen's kappa statistical analyses. Results: The model's validation and test accuracy for the six-class CVM diagnosis were 62.63% and 61.62%, respectively. Moreover, the model's validation and test accuracy for the three-class classification were 75.76% and 82.83%, respectively. Furthermore, substantial agreements were observed between the two orthodontists as well as one of them and the AI model. Conclusions: The newly developed AI model had reasonable accuracy in detecting the CVM stage and high reliability in detecting the pubertal stage. However, its accuracy was still less than that of human observers. With further improvements in data quality, this model should be able to provide practical assistance to practicing dentists in the future.

• 대한소아치과학회지
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• 제46권3호
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• pp.233-238
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• 2019

본 연구의 목적은 한국 소아청소년 표준 골연령 도표를 이용하여 평가한 SMI 및 MP3 단계별 골연령을 조사하여 최대 성장기에 해당하는 단계를 알아보고, 이를 통해 성장 중인 부정교합 환자의 치료 계획 수립, 치료방법 및 시기에 중요한 영향을 미치는 성장 발육평가 자료를 제공하고자 함이다. 이대목동병원 소아청소년과에 내원한 363명의 환자의 수완부 방사선 사진에서 한국 소아 청소년의 표준 골연령 도표를 바탕으로 영상의학과 의사에 의해 판정된 골연령을 조사하였다. 동일한 방사선 사진에서 평가된 SMI 및 MP3 단계에 따른 평균 골연령을 산출하였다. 본 연구 결과 사춘기 최대 성장기가 남아에서는 SMI 4 - 5단계 및 MP3 FG - G단계, 여아에서는 SMI 3 - 4단계 및 MP3 F - FG단계에서 나타남을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권9호
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• pp.1338-1350
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• 2012

This review focuses on the nutritional effects from birth until age at first calving on growth, mammary developmental changes, and first-lactation milk yield in heifer calves. The advancement in the genetic potential and the nutritional requirements of the animals has hastened the growth rate. Genetic selection for high milk yield has suggested higher growth capacity and hence increasing nutritional inputs are required. Rapid rearing by feeding high energy or high concentrate diets not only reduces the age of sexual maturity but also lowers the time period of attaining the age of first calving. However, high energy diets may cause undesirable fat deposition thereby affecting future milk yield potential. Discrepancies exist whether overfed or overweight heifers at puberty can influence the mammary development and future milk yield potential and performance. The data on post-pubertal nutritional management suggested that body weight at calving and post-pubertal growth rate is important in first lactation milk yield. There is a continuous research need for strategic feeding that accelerates growth of dairy heifers without reduction in subsequent production. Nutritional management from birth, across puberty and during pregnancy is critical for mammary growth and for producing a successful cow. This review will mostly highlight studies carried out on dairy breeds and possible available opportunities to manipulate nutritional status from birth until age at first calving.

• 한국발생생물학회지:발생과생식
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• 제25권2호
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• pp.83-91
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• 2021

The present study was performed to investigate the effect of maternal hypothyroidism and puberty onset in female rat pups. To do this, we employed propylthiouracil (PTU) to prepare a hypothyroid rat model. Pregnant rats were treated with PTU (0.025%) in drinking water from gestational day 14 to postnatal day 21 of offspring. Comparison of general indices such as body and tissue weights and puberty indices such as vaginal opening (VO) and tissue histology between control and PTU-treated rats were conducted. There was no significant difference in the date of VO between control and PTU group. The body weights of the PTU group were significantly lower, only 36.8% of the control group (p<0.001). Although the absolute thyroid weight was not changed by PTU treatment, the relative weight increased significantly about 2.8 times (p<0.001), indicating that hypothyroidism was successfully induced. On the other hand, the absolute weights of the ovary and uterus were markedly decreased by PTU administration (p<0.001), and the relative weight was not significantly changed. The ovarian histology of PTU group revealed the advanced state of differentiation (i.e., presence of corpora lutea). Inversely, the uterine histology of PTU group showed underdeveloped structures compared those in control group. Taken together, the present study demonstrates that our maternal hypothyroidism model resulted in minimal effect on pubertal development symbolized by VO despite of huge retardation in somatic growth. More sophisticatedly designed hypothyroidism model will be helpful to achieve a better understanding of pubertal development and related disorders.

• Journal of Animal Science and Technology
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• 제64권4호
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• pp.654-670
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• 2022

Spermatogenesis and testis development are highly structured physiological processes responsible for post-pubertal fertility in stallions. Spermatogenesis comprises spermatocytogenesis, meiosis, and spermiogenesis. Although germ cell degeneration is a continuous process, its effects are more pronounced during spermatocytogenesis and meiosis. The productivity and efficiency of spermatogenesis are directly linked to pubertal development, degenerated germ cell populations, aging, nutrition, and season of the year in stallions. The multiplex interplay of germ cells with somatic cells, endocrine and paracrine factors, growth factors, and signaling molecules contributes to the regulation of spermatogenesis. A cell-tocell communication within the testes of these factors is a fundamental requirement of normal spermatogenesis. A noteworthy development has been made recently on discovering the effects of different somatic cells including Leydig, Sertoli, and peritubular myoid cells on manipulation the fate of spermatogonial stem cells. In this review, we discuss the self-renewal, differentiation, and apoptotic roles of somatic cells and the relationship between somatic and germ cells during normal spermatogenesis. We also summarize the roles of different growth factors, their paracrine/endocrine/autocrine pathways, and the different cytokines associated with spermatogenesis. Furthermore, we highlight important matters for further studies on the regulation of spermatogenesis. This review presents an insight into the mechanism of spermatogenesis, and helpful in developing better understanding of the functions of somatic cells, particularly in stallions and would offer new research goals for developing curative techniques to address infertility/subfertility in stallions.

• Journal of Nutrition and Health
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• 제40권1호
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• pp.69-77
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• 2007

The study was conducted to investigate the factors associated with bone mineral content (BMC) changes among early pubertal aged girls. Two hundred and thirty girls between 9 to 11 years of age participated in (our surveys over 2 year period. During each survey, dietary intakes were collected with 3-day food records, BMC of left leg's calcaneus were measured by PIXI (Lunar Ltd.) and body composition was measured by bioimpedance method (Inbody 3.0 Biospace Co. Ltd, Seoul, Korea). Mean values of BMC increased in consecutive measurements -1.48 g, 1.54 g, 1.61 g and 1.66 g. The change of BMC between the first and last measurements was significantly positively correlated with % body fat, negatively correlated with BMC at the baseline (p < 0.05). Change of BMC was also significantly positively correlated with % change of lean mass and mineral mass between the first and last measurements. Nutrient intakes during the study period were calculated as mean daily intakes from all surveys. Mean daily intakes of Vit. C and Vit. $B_6$ were positively and isoflavone intake was negatively correlated with changes of BMC (p < 0.05). In stepwise regression of BMC change with body composition and nutrient intakes, baseline values of BMC, weight, BMI and age, % change of mineral mass during the study period, mean intakes of isoflavone, Vit. $B_6$, protein, carotene and zinc were significant explanatory variables ($R^2=0.38$, p <.001, F = 32.39). The results imply that the change of BMC among early pubertal aged girls are associated with some body composition and intakes of certain nutrients.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.146-151
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• 2010

목 적 : 저자들은 우리나라 초등학교 저학년의 사춘기 발현 시기를 조사하고, 사춘기 발현시기에 영향을 미치는 인자에 대해서 연구하고자 하였다. 방 법 : 고양시 관내 초등학교 1, 2, 3학년 학생들을 무작위로 선별하여 신체검진을 통해 이차성징의 발현유무를 조사하였다. 부모의 동의와 함께 설문조사를 하여 비만도, 식생활 패턴, 생활습관, 성장촉진제품 복용여부 등을 조사하여 사춘기 조기 발현의 영향인자를 통계학적으로 분석하였다. 결 과 : 총 170명의 학생이 선별되었으며 남녀비는 1:1.2였다. 대상 환아들의 연령은 6-9세였으며, 각 연령에서 이차성징을 보인 경우는 남아는 9세에서 2명(25.0%)이었고, 여아에서는 6세는 2명(14.3%), 7세는 6명(19.4%), 8세는 15명(39.6%), 9세는 4명(57.1%)이 이차성징을 보였다. 여아의 예측 평균 사춘기 발현 시기는 $9.11{\pm}1.86$세였다. 사춘기 발현 시기에 영향을 미치는 인자로 통계학적 유의성을 보인 것은 비만도, 패스트푸드 섭취빈도, 성장촉진제품 복용이었다. 비만도가 높을수록 패스트푸드 섭취빈도가 높을수록 사춘기 발현시기가 빨랐다. 성장관련제품을 복용하는 군이 사춘기 발현시기가 빨랐으나 비만도가 높아짐으로 인해 빨라진 것으로 나타났다. 결 론 : 본 연구의 결과 여아의 예측 평균 사춘기 발현 시기가 $9.11{\pm}1.86$세로서 국외의 결과와 유사함을 알 수 있었고, 사춘기 조기 발현에 영향을 미치는 인자는 비만도와 패스트푸드의 섭취 빈도였다.