• Journal of radiological science and technology
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• v.44 no.3
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• pp.195-203
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• 2021

Although intra oral dental x-ray is a lower dose than other radiological examinations, pediatric patients are known to have a higher risk of radiation damage than adults. For this reason, pediatric dental x-ray requires management of dose evaluation and imaging conditions during the examination. In this study, the dose calculation program ALARA-Dental(child/adult) was used to evaluate the organ dose and effective dose exposed to each examination site during intra oral imaging of children during dental radiographic examination, and dose analysis according to the imaging conditions was performed. As a result, the highest organ dose distribution was shown at 0.044 ~ 0.097 mGy in all are as of the mucous membrane of oral cavity except for the maxillary incisors and canines. Also, in the case of the thyroid gland, the maxillary canine and maxillary premolar examination showed 0.027 and 0.020 mGy, respectively, and the dose distribution was 15.4% to 70.0% higher than that of the mandibular examination. As for the effective dose calculated during intra oral imaging, the maxillary anterior and canine examinations showed the highest effective doses of 0.005 and 0.004 mSv, respectively, and the maxillary area examination showed a higher dose distribution on average than the mandible.

• Journal of Life Science
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• v.11 no.6
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• pp.582-594
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• 2001

This experiment was performed to investigate the effects of sulfur dioxide on the histological changes, properties of mucosubstances and glycoconjugates of the nasal respiratory mucosa in the rat. Sprague-Dawley male rats weighing about 200~250g were divided into a control group and SO$_2$ exposed groups. Again SO$_2$ exposed groups were divided into 10 ppm, 25 ppm, 50 ppm, 100 ppm, and 200 ppm subgroups, according to concentrations of SO$_2$ and each SO$_2$exposed groups were divided into 1, 3 and 6 hours groups. For the histological changes, hematoxylin-eosin(H-E) and periodic acid Schiff's(PAS) stainings were used, and for the properties of mucosubstances, PAS, alcian blue (AB) pH 2.5, pH 2.5-PAS, AB pH 1.0 and aldehyde fuchsin (AF) pH1.7-AB pH 2.5 were used. In all the SO$_2$ exposed groups, loss of cilia and detachment of epithelial cells, vacuolation of goblet cells were observed in the respiratory epithelium while epithelial squamous metaplasia and intraepthelial mucous cells were observed in the higher concentration of SO$_2$ and the degree of the loss cilia was higher according as concentration was higher and exposed time was longer. The intraepitheial mucous cells appeared most remarkable in the 50 ppm SO$_2$ exposed group. The numbers of goblet cells and acini of nasal septal gland were varied according to concentration of SO$_2$ and exposed time, but the numbers in the 25 ppm and 50 ppm, SO$_2$ exposed increased remarkably. However, the numbers in the 100 ppm and 200 ppm SO$_2$ exposed group had a tendency to decrease noticeably, or disappeared.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.115-127
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• 1998

The digestive tract of the rockfish, Sebastes schlegeli composed of pharynx, esophagus, stomach, intestine, anus and ten or eleven pyloric caeca. Pyloric caeca is blind sac of banana shape, and that is originated from pyloric portion of the stomach. The relative length of gut(RLG), that is length of digestive tract to standard length, is about 1.56(n=10). Esophageal muscularis consists of thin outer layer of longitudinal muscle and thick inner layer of circular muscle. Mucosal epithelium consists of columnar epithelium with short microvilli and contains numerous mucous secretory cell. The mucosal folds of the stomach are regular, and the muscularis consists of longitudinal, oblique and circular muscle layer. The chief cell of the gastric gland have a tubular mitochondria, endoplasmic reticula and numerous secretory granules in electron-dense. However, parietal cell contains small mitochondria, endoplasmic reticula and vacuoles in low electron density. Mucosal epithelium of the pyloric caeca and intestine composed of columnar epithelium, goblet cell, rodlet cell and dark cell. Columnar absorptive cell in the pyloric caeca and intestine contains well developed mitochondria, endoplasmic reticula, vesiculated granules in high electron density, pinocytotic vesicles and multivesicular body. Rodlet cell have a well developed cytoplasmic capsule and the endoplasmic reticula in the cytoplasm. Dark cell showing a high electron density in the cytoplasm and contains well developed mitochondria. Columnar epithelium of the intestine have a well developed intercellular junction and the microvilli which contains actin filament originated from the cytoplasm. Mucosal epithelium of the intestine have a longer microvilli and more abundant goblet cells than in the pyloric caeca.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.88-94
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• 2011

Ranula is a mucosal cyst that occurs in the mouth floor. This is a pseudo cyst caused by mucous retention within the tissue due to the rupture of catheter in the salivary gland. Ranula occurs mainly in a unilateral form and is characterized by painless bluish transparent swelling, with a increasing mass size. If the size is large, it can cause discomfort during swallowing, pronounciation, and mastication, but external swelling and infection is rare. Treatments include observation for spontaneous resolution, simple incision and drainage, marsupialization and excision. Marsupialization done by removing parts of the cyst wall and connecting it to the oral mucosa. It is a conservative procedure and recommended for children. It has advantages such as maintaining outline of oral tissue and less risk of damaging anatomic structure. Recurrence is common, mostly occurring within 4 months after surgery. This case is about a eight-year-old girl with ranula on the right mouth floor. This patient was treated with marsupialization that is one of treatment for ranula, and recurrence was not observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.413-417
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• 2002

Mucocele is a mucous retention phenomenon which is caused by a laceration to the duct of minor salivary glands causing extravasation of mucin into the connective tissue forming a cyst-like space. Sialolithiasis of minor salivary glands and chronic obstruction of salivary glands may also cause such a phenomenon. Mucocele is a smooth, rounded sessile mass with diameters varying from 1 to 15mm of sudden appearance. Mucocele tying directly beneath the mucosa may rupture spontaneously and decrease in size, but frequently recurs. Lower lip is most frequently affected, and the mouth floor and buccal vestibule may also be affected. Enucleation of the cyst is needed and removal of minor salivary glands, marsupialization and cryotherapy may also be done. The mucocele frequently recurs after its removal. A 1-year-old female patient visited the hospital with a complaint of a swelling on the lower lip since 4 months before. She had no pain history but 4 months ago, fell and such symptom appeared since then. On her first visit, a bullous solid, opaque lesion of 5mm in diameter was noted. Treatment choice of surgical approach and nonsurgical approach were explained to the guardian. Considering the patient's age, the guardian agreed to a nonsurgical procedure. Treatment was carried out by tieing 3-0 silk to the base of the lesion. One week later, the tie loosened and was re-tied. A week later, the mucocele disappeared. Mucocele on the lower lip may be usually be treated by surgical removal, but this may traumatize the surrounding minor salivary gland causing it to recur. Also, surgicial removal may induce an ischemic change causing sialometaplasia. In case of young patients or children with management problems, non-surgical methods such as this tie method may be used. This tie method does not need any local anesthesia and has no pain, no secondary infection, and low bleeding tendency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.642-648
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• 1999

The digestive tract of the black sea bream, Acanthopagrus schlegeli is composed of esophagus, stomach, intestine, anus and four or five pyloric caeca. Pyloric caecum is a blind sac in shape and originated from pyloric portion of the stomach. Relative length of But (RLG), that is length of digestive tract to standard length, is 1.04 (n=10). Histological layer of the digestive tract is composed of serous membrane, muscular layer, undeveloped submucosal layer and mucosal layer. The mucosal folds of the esophagus are regular branched form, Esophageal muscularis mucosae is well-developed. Mucosal epithelial layer is composed of cuboidal or columnar epithelium and mucous secretory cell. Microvilli are absent in the free surface of mucosal epithelium. The mucosal folds of the stomach are regular unbranched form. The stomach has a well-developed muscular layer and muscularis mucosae. Microvilli are present in the free surface of mucosal surface epithelium. The fundic portion of the stomach have a well-developed gastric gland and more numerous secretory granules than the other parts. The mucosal folds of the pyloric caeca and the intestine are irregular branched form, Intestine is divided into the anterior, mid and posterior intestines with length of mucosal folds and histological features, Posterior intestine has a more developed striated border and goblet cells than the other parts. Mid intestine has a more abundant absorptive cells than the other parts in the intestine and pyloric caeca.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.125-134
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• 1980

The dovelopment of the gonads, gametogenesis and the reproductive cycle of the topshell, Turbo cornutus Solander, which is one of valuable food animals fom Korean waters were studied by photomicroscophy. The materials were monthly collected from Bangeojin, Jeongjari and Dangweol, all these places being located in the south-eastern part of Korea, for one year from March 1979 to February 1980. Topshell is dioecious and oviparous. Gonad is situated on the surface of liver, which lies posteriorly. The surface of ovary and testis is covered with a fibrous membrane, membrane of connective and muscular fibers and then an outermost layer of simple-columnar epithelial cells which are composed of cuboidal and columnar mucous gland cells. Primordial germ cells develop on the germinal epithelium of ovarian and testicular lobuli which are originated from the fibrous membrane and extend toward hepatic gland. Undifferentiated mesenchymal tissue and pigment granular cells are abundantly distributed between the growing oocytes and spermatocytes in the early development stages. With the further development of the ovary and testis these tissue and cells gradually disappear. Then the undifferentiated mesenchymal tissue and pigment granular cells are considered to be related to the growing of the oocytes and spermatocytes. Early multiplicating oogonium is ca. $10\mu$ in diameter and nucleushaving a central nucleolus is ra. $8\mu$. As the oocytea grow to ca. $50-60\mu$ by the increase of cytoplasm, the oocytes become look like bunches of grapes which are attached to ovarian lobuli. Mature eggs are ca. $180-210\mu$ in diameter and it is surrounded by a gelatinous membrane of ca. $10\mu$ in thickness. After spawning, undischarged ripe eggs and spermatozoa remain in the ovary and testis respectively for some time. Then they finally degenerate, and proliferation of new oogonia and spermatogonia occur along the germinal epithelia of newly developed ovarian and testicular lobuli. Reprocuctive cycle of Turbo cornutus could be classified into five successive stages: multiplicative, growing, maturer spent and recovery stages. Spawning occurs from August to November with Peak spawning from early September to late October.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.129-136
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• 2000

Differentiation and development of the digestive organ of the black sea bream, AcanHepagus schlegeli were studied by means of histological methods. The hatched lawn if TL(total length) $2.0 mm (n=10)$ had a yolk sac of $1,000{\times}590 {\mu}m$ and simple straight digestive tract, which was composed of cuboidal epithelium. In the pre-larval stage of TL $3.5 mm$, digestive tract could be distinguished into esophagus, stomach and intestine, and the exocrine glands were appeared in the pancreas. In this stage mucosal folds, eosinophilic granule cells and brush border were observed in the posterior intestine. Yolky materials were completely absorbed and the brush border was recognized in the free surface of anterior intestine in TL $3.7 mm$. In the stomach mucosal folds began to appear from TL $4.0 mm$. In this time the zymogen granules were recognized in the cytoplasm of pancreatic exocrine cells. In the post-larval stage ranged from $4.5 to 5.0 mm$ in TL, hepatic cords started to develop, and the mucous secretory cells of PAS positivewere observed at esophagus and intestine. In the post-larval stage ranged from $6.3 to 7.0 mm$ in TL, histological layer of esophagus and intestine could be distinguished into serous membrane, muscular layer, submucosal layer and mucosal layer. From over TL $9.0 mm$, stomach could be distinguished into cardiac, fundic and pyloric portion, and the gastric gland began to appear at mucosal fold of fundic stomach. In the juvenile stage ranged from $10.0 to 11.0 mm$ in TL, histological structures of esophagus and intestine were similar to those of adult. From over TL $15.0 mm$, histological structures of stomach were similar to those of adult. Structural and functional digestive organ of black sea bream was present from the juvenile stage ranged from $15.0 to 17.0 mm$ in TL.