• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1092-1104
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• 2022

Using antibiotics as growth promoter has been banned in poultry feed industry, thus various researchers try to seek an alternative to replace the growth-promoting antibiotics. In this study, we aimed to evaluate the growth performance via intestinal nutrient utilization and cecal microbial composition of broiler after dietary supplementation with most commonly using antibiotics, zinc bacitracin, and sophorolipid. A total of 180 1-day-old chicks were randomly assigned, and dietary treatment was as follow: CON, basal diet; ZB, 100 ppm of zinc bacitracin supplemented diet; and SPL, 250 ppm of sophorolipid supplemented diet. Their growth performance was evaluated and the samples of blood, small intestine, and ileal and cecal digesta were collected for biochemical, histological, and genomic analyses. The body weight and average daily gain of 7-day-old chicks were higher in ZB and those in overall experimental period were improved by ZB and SPL supplementation (p < 0.05). Their intestinal characteristics were not affected by dietary treatments in duodenum and ileum. Nonetheless, villus height was increased by SPL supplementation in jejunum (p < 0.05). Moreover, dietary SPL supplementation could down-regulate the expression level of pro-inflammatory cytokine, IL-1β (p < 0.05). mRNA levels of lipid and protein transporters did not differ among the treatments, however, relative expression levels of carbohydrate transporters, GLUT2 and SGLT1 were increased in broiler chicken's jejumum fed zinc bacitracin and sophorolipid supplemented diets (p < 0.05). Dietary zinc bacitracin supplementation could increase the population of Firmicutes in phylum level, and the portion of Turiciacter in genus level. On the other hands, the portion of Faecalibacterium was increased by dietary SPL supplementation compared to the other treatments. Our findings suggest that SPL supplementation improves growth performance through enhanced carbohydrate utilization capacity via improvement of gut morphological status and modulation of the cecal microbial population of broilers.

• The korean journal of orthodontics
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• v.53 no.6
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• pp.393-401
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• 2023

Objective: To investigate the long-term effects of 4-hexylresorcinol (4HR) on facial skeletal growth in growing male rats, with a focus on diabetic animal models. Methods: Forty male rats were used. Of them, type 1 diabetes mellitus was induced in 20 animals by administering 40 mg/kg streptozotocin (STZ), and they were assigned to either the STZ or 4HR-injected group (STZ/4HR group). The remaining 20 healthy rats were divided into control and 4HR groups. We administered 4HR subcutaneously at a weekly dose of 10 mg/kg until the rats were euthanized. At 16 weeks of age, whole blood was collected, and microcomputed tomography of the skull and femur was performed. Results: All craniofacial linear measurements were smaller in the STZ group than in the control group. The mandibular molar width was significantly smaller in the 4HR group than in the control group (P = 0.031) but larger in the STZ/4HR group than in the STZ group (P = 0.011). Among the diabetic animals, the STZ/4HR group exhibited significantly greater cortical bone thickness, bone mineral density, and bone volume than the STZ group. Serum testosterone levels were also significantly higher in the STZ/4HR group than in the STZ group. Conclusions: 4HR administration may have divergent effects on mandibular growth and bone mass in healthy and diabetic rats. In the context of diabetes, 4HR appears to have beneficial effects, potentially through the modulation of mitochondrial respiration.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.412-419
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• 2009

The purpose of this study was to provide the reference data evaluating the treatment effect of orthopedic appliances. The skeletal and dental growth increments were measured in 24 normal mixed dentition children (boys: 14, girls: 10) by three serial lateral cephalograms: initial mean age: 9${\pm}$1.3 years, mean observation period: 13${\pm}$1.3 months. Cephalometric changes were analysed. The results were as follows: 1. In boys, the maxilla showed forward and downward growth pattern and the mandible showed forward growth pattern (p<0.05). In girls, the maxilla and mandible showed forward and downward growth pattern(p<0.05). 2. Horizontal growth of both maxilla and mandible in girls was superior to those in boys (A point; girls: 2.39mm, boys: 1.26mm, with p<0.05), whereas vertical growth of both maxilla and mandible in boys was similar to those in girls. 3. The change in tooth axis showed labioversion of upper incisor (p<0.01) and comparatively stable lower incisor position.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.270-275
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• 2011

Fibrous dysplasia is a developmental tumor-like condition that is characterized by replacement of normal bone by an excessive proliferation of cellular fibrous connective tissue intermixed with irregular bony trabeculae. Craniofacial lesions may cause facial pain, headache, cranial asymmetry, facial deformity, tooth displacement and visual or auditory impairment. In this case, a 2-year-9-month old boy who was diagnosed as the fibrous dysplasia showed delayed eruption on affected area. Teeth of left lateral dentition group have erupted completely but teeth of right lateral dentition group are erupting slowly. Eruption and maturation of affected teeth are in progress, so continuous observation is required presently. If the eruption state stops, surgical opening or forced eruption of the impacted teeth will be considered.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.175-182
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• 2012

Purpose: The aim of this study was to provide sex-matched three-dimensional (3D) statistical shape models of the mandible, which would provide cephalometric parameters for 3D treatment planning and cephalometric measurements in orthognathic surgery. Materials and Methods: The subjects used to create the 3D shape models of the mandible included 23 males and 23 females. The mandibles were segmented semi-automatically from 3D facial CT images. Each individual mandible shape was reconstructed as a 3D surface model, which was parameterized to establish correspondence between different individual surfaces. The principal component analysis (PCA) applied to all mandible shapes produced a mean model and characteristic models of variation. The cephalometric parameters were measured directly from the mean models to evaluate the 3D shape models. The means of the measured parameters were compared with those from other conventional studies. The male and female 3D statistical mean models were developed from 23 individual mandibles, respectively. Results: The male and female characteristic shapes of variation produced by PCA showed a large variability included in the individual mandibles. The cephalometric measurements from the developed models were very close to those from some conventional studies. Conclusion: We described the construction of 3D mandibular shape models and presented the application of the 3D mandibular template in cephalometric measurements. Optimal reference models determined from variations produced by PCA could be used for craniofacial patients with various types of skeletal shape.

• Development and Reproduction
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• v.13 no.2
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• pp.89-95
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• 2009

p63 has been demonstrated to localize in stem cells and precursor cells of various epithelial tissues previously, but the localization of p63 throughout tooth formation, particularly during the enamel and root formation stages, remains to be adequately characterized. Therefore, in this study, we have demonstrated, via immunohistochemical methods, that p63 is ubiquitously expressed in the dental epithelium during tooth development. p63 was detected in the basal and suprabasal layers of the epithelia, including the skin, hair follicles, oral mucosa, and submandibular ducts. However, in the tooth region, all cells of the dental lamina, enamel organ, Hertwig's epithelial root sheath (HERS), and epithelial cell rests of Malassez (ERM) evidenced immunoreactivity for p63. These results indicate that p63 may perform different roles, other than stem cell maintenance, in tooth development.

• Journal of Veterinary Clinics
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• v.33 no.4
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• pp.234-236
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• 2016

A 14 kg, 9-year-old, spayed female, Cocker Spaniel was presented to the Veterinary Medical Teaching Hospital of Seoul National University with a history of head tilt and circling. Otitis externa and media were diagnosed by computerized tomography, and total ear canal ablation was performed. In preanesthetic evaluation, systemic hypertension and second-degree atrioventricular block were observed, but there was no regurgitation through the heart valves. Systemic hypertension was managed with amlodipine (0.1 mg/kg, PO, BID) for the anesthesia. The dog was premedicated with cefazolin (22 mg/kg, IV) and midazolam (0.2 mg/kg, IV). Anesthesia was induced with alfaxalone (2 mg/kg, IV) and maintained with isoflurane and 100% oxygen following intubation. During surgery, vital signs (heart rate, respiratory rate, blood pressure, end tidal carbon dioxide partial pressure and body temperature) were maintained within normal ranges, but bradycardia was observed and corrected with glycopyrrolate (5 ug/kg IV, twice). During subcuticular suture, electrohemostasis was applied at the incision line, which was close to the trigeminal nerve. In no time at all, heart rate dramatically decreased from 110 to 60 beats per minute. No additional treatment was done because mean blood pressure was maintained above 70 mmHg. The heart rate recovered according to the decrease of end tidal isoflurane concentration and there were no complications associated with the anesthesia and surgery. Sudden bradycardia after electrical stimulation around the trigeminal nerve was considered as trigeminocardiac reflex (TCR). It is recommended to be careful of bradycardia from TCR when electrocautery is used in the craniofacial area during surgery.

• Journal of Periodontal and Implant Science
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• v.47 no.3
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• pp.143-153
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• 2017

Purpose: The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods: The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results: During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions: Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket healing.

• The korean journal of orthodontics
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• v.48 no.6
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• pp.384-394
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• 2018

Objective: This study was performed to investigate an appropriate degree of prestretch for orthodontic synthetic elastomeric chains focusing on time-dependent viscoelastic properties. Methods: Orthodontic synthetic elastomeric chains of two brands were prestretched to 50, 100, 150, and 200% of the original length in one and three cycles, and the hysteresis areas of the obtained stress-strain curves were determined. Acrylic plates were employed to maintain constant strain during the experiment. A total of 180 samples were classified into nine groups according to brand, and their stresses and permanent deformations were measured immediately after prestretch (0 hour), after 1 hour and 24 hours, and after 1, 2, 3, 4, 5, 6, 7, and 8 weeks. The relationship between stress relaxation and permanent deformation was investigated for various degrees of prestretch, and the estimated stress resulting from tooth movement was calculated. Results: The degree of prestretch and the stress relaxation ratio exhibited a strong negative correlation, whereas no correlation was found between the degree of prestretch and the average normalized permanent strain. The maximal estimated stress was observed when prestretch was performed in three cycles to 200% of the original length. Conclusions: Although prestretch benefited residual stress, it did not exhibit negative effects such as permanent deformation. The maximal estimated stress was observed at the maximal prestretch, but the difference between prestretch and control groups decreased with time. In general, higher residual stresses were observed for product B than for product A, but this difference was not clinically significant.

• Journal of Periodontal and Implant Science
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• v.46 no.2
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• pp.96-106
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• 2016

Purpose: Stress distribution and mandible distortion during lateral movements are known to be closely linked to bruxism, dental implant placement, and temporomandibular joint disorder. The present study was performed to determine stress distribution and distortion patterns of the mandible during lateral movements in Class I, II, and III relationships. Methods: Five Korean volunteers (one normal, two Class II, and two Class III occlusion cases) were selected. Finite element (FE) modeling was performed using information from cone-beam computed tomographic (CBCT) scans of the subjects' skulls, scanned images of dental casts, and incisor movement captured by an optical motion-capture system. Results: In the Class I and II cases, maximum stress load occurred at the condyle of the balancing side, but, in the Class III cases, the maximum stress was loaded on the condyle of the working side. Maximum distortion was observed on the menton at the midline in every case, regardless of loading force. The distortion was greatest in Class III cases and smallest in Class II cases. Conclusions: The stress distribution along and accompanying distortion of a mandible seems to be affected by the anteroposterior position of the mandible. Additionally, 3-D modeling of the craniofacial skeleton using CBCT and an optical laser scanner and reproduction of mandibular movement by way of the optical motion-capture technique used in this study are reliable techniques for investigating the masticatory system.