• The korean journal of orthodontics
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• v.41 no.3
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• pp.174-183
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• 2011

Objective: Orthodontically induced root resorption (OIRR) involves partial loss of cementum and dentin of teeth caused by routine orthodontic treatment. It decreases root length and influences the function of affected teeth. In this study, the treatment and patient factors causing apical root resorption in Koreans were determined. The observed factors were extraction, gender, age, displacement of root apex, total treatment period, total teeth length, and shape of the root. Methods: The records of 137 patients treated with full, fixed edgewise appliances were obtained from the Department of Orthodontics, Dankook University Dental Hospital, from November 2007 to December 2008. Periapical radiographs of the maxillary central incisors and cephalometric radiographs of each patient were used to assess apical root resorption and type of tooth movement. Results: The mean amount of resorption was $1.62{\pm}1.58mm$. The amount of resorption in the extraction and non-extraction groups was $2.10{\pm}1.64mm$ and $1.18{\pm}1.39mm$, respectively. The amount of root resorption increased with the total tooth length. Severe root resorption (> 4 mm) was related to abnormal root shape (blunt, pointed, or eroded). Conclusions: The variables significantly related to OIRR were extraction, initial tooth length, and root shape.

• Journal of Korean Neurosurgical Society
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• v.52 no.4
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• pp.384-390
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• 2012

Objective : The objective of this study was to investigate the morphologic characteristics between the vertebral body and the regions of the cervical and thoracic spinal cords where each rootlets branch out. Methods : Sixteen adult cadavers (12 males and 4 females) with a mean age of 57.9 (range of 33 to 70 years old) were used in this study. The anatomical relationship between the exit points of the nerve roots from the posterior root entry zone at each spinal cord segment and their corresponding relevant vertebral bodies were also analyzed. Results : Vertical span of the posterior root entry zone between the upper and lower rootlet originating from each spinal segment ranged from 10-12 mm. The lengths of the rootlets from their point of origin at the spinal cord to their entrance into the intervertebral foramen were 5.9 mm at the third cervical nerve root and increased to 14.5 mm at the eighth cervical nerve root. At the lower segments of the nerve roots (T3 to T12), the posterior root entry zone of the relevant nerve roots had a corresponding anatomical relationship with the vertebral body that is two segments above. The posterior root entry zones of the sixth (94%) and seventh (81%) cervical nerve roots were located at a vertebral body a segment above from relevant segment. Conclusion : Through these investigations, a more accurate diagnosis, the establishment of a better therapeutic plan, and a decrease in surgical complications can be expected when pathologic lesions occur in the spinal cord or vertebral body.

• Journal of Ginseng Research
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• v.3 no.2
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• pp.105-112
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• 1979

Effect of gibberllin on the breaking of bud dormancy of root and growth of aerial parts were investigated under laboratory and field condition for the prolongation of shoot growth duration, shortening of fruit bearing age and the increase of root yield. Drop application of GA (0.5ml of 50ppm) on rhizome of one year old root broke bud dormancy better than by low temperature. Soaking for one hour of one year old roots which wintered in the field in GA (50-200ppm) greatly accelerated the emergence of new buds while kinetin was only effective at low level (50ppm). GA substantially increased stem length in early stage and petiole length later on while kinetin increased stem diameter. Under the field condition with polythylene film tunnel (PET) in early spring the soaking in GA (50ppm for 1 hour) of rhizome of 4 year old root with replanting and dropping GA (50ppm, 1ml) on rhizome without replanting brought earlier emergence (29days) in comparison with that in the usual field. PET alone caused 14 day-early emergence. GA increased the length of stem and petiole only in early stage and replanting decreased only petiole length in later stage. Soaking in GA with replanting caused the Pronounced decrease in peduncle length, percentage of (ruin set and dry weight of reproductive organ (fruits and peduncle). Dropping without replanting showed significant decrease only in dry weight of reproductive organ. Fruit maturing was 20 days earlier than in usual held with little difference between GA and PET. It is well expected that GA could be used for early emergence of bud, shortening of root dormancy period, thinning of fruit and higher root yield according to application amount and methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.284-288
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• 2004

The response of dissolved oxygen (DO) concentrations caused significant change in root number, root length, coleoptile length, shoot length and leaf age of seedlings. The genotypic difference in the effect of DO also highly significant (P<0.01) for all of the seedling traits. The number and length of root were extremely inhibited at the condition of $0.39\pm0.09$ DO concentration. While the coleoptile elongated markedly in the lowest DO concentrations, the shoot did not develop. The root growth was improved slightly at the $1.39\pm0.27mg L^{-1}$, however, there were no difference among genotypes at these two low DO concentrations. As the DO concentration become higher, the growth of root and shoot was improved remarkably. Root number, root length and shoot length was significantly different between $20\;and\;30^{\circ}C$ in DO rich and normal conditions, the development of those traits were apparently accelerated in high water temperature, however those traits of seedlings in DO deficiency were not different between the two temperatures except for shoot length. On the other hand the coleoptile length was not affected by the stagnant water temperature; it was stimulated by the low DO concentration. The competition of DO was greater as the seedling density was increased in the stagnant water, therefore the seedlings grown under high density have long and white coleoptiles, and the growth of roots and shoots was retarded severely.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.644-651
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• 1999

It is a relatively common clinical experience to see an unerupted maxillary central incisor. This phenomenon is apparent at the dental age of almost eight years and over. Among the possible cause for failure of eruption, ectopic development of the tooth germ is mentioned. This is not fully understood but trauma or periapical imflammation of primary predecessors is accepted. The case with no history of trauma may be impacted by the periapical imflammation of primary predecessors. For bringing into the tooth eruption and the continued normal root developement by the Hertwig's epithelial root sheath, there are early considered of surgical invention and orthodontic traction with removable appliance. We reported successful treatment for inverted maxillary central incisor with proper eruption and normal root developement by forced eruption using removable appliance. But further observation will be required to evaluate the final root developement state and amount of keratinized attachment gingiva.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.539-547
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• 2009

This study was conducted to investigate the arbuscular mycorrhizal fungal biodiversity, spore density and root colonization in relation to site ages at expressway cut-slopes in Korea. Stabilization of exposed surface involved soil amendments and spraying seed mixture of turf grasses and/or nitrogen-fixing shrub species. Eighteen sites were selected with varying ages (2 to 16 years). Soil samples collected in October from each site were analyzed for fungal diversity and spore counts. Fine root samples from the plants were assayed for fungal colonization. Of the total 37 plants inspected in the sites, 26 species had endomycorrhizal colonization with an average root colonization rate of 18%, and with a range from 1 to 67%. The average endomycorrhizal colonization rate of initially introduced Festuca arundinacea which became the most dominant grass in later stage showed 22.8%, while that of Lespedeza bicolor which became the most dominant woody species were 21.6%. Naturally-invading Robinia pseudoacacia showed higher colonization rate in the old sites. Although site age did not show significant effects on fungal diversity, the root colonization rates of initially introduced plants decreased with the site aging, while those of invading plants increased with aging of the sites. The soil chemical properties, pH, N, and P contents, were negatively correlated with spore density, root colonization and endomycorrhizal species diversity. A total of forty arbuscular mycorrhizal fungal species in seven genera were identified. Of the 40 species, Acaulospora lacunosa, Glomus aggregatum, Glomus constrictum, Scutellospora erythropa, and Acaulospora spinosa were the five most dominant species in the decreasing order.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.133-136
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• 2011

The medial meniscal root tear is relatively common internal derangement of knee that is occurred in middle age without trauma. We experienced a case of traumatic medial meniscal root tear in 11 years old child and repaired it with a metallic suture anchor. Thus we report this case with a review of current literature.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.445-448
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• 2023

A 25-year-old man returned to Seoul National University Children's Hospital with mild dyspnea on exertion. He had undergone an arterial switch operation at 1 month after birth to correct a complete transposition of the great arteries and a ventricular septal defect. When the patient was 15 years old, dilatation of the neo-aortic sinus and annulus was first identified; since then, it had gradually increased. Given the young age of the patient and the degree of aortic regurgitation (AR), which was mild to moderate, we opted to perform a valve-sparing neo-aortic root replacement with aortic valve repair. Postoperative echocardiography showed successful reductions in the sizes of the aortic sinus and annulus, with only mild AR remaining.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.192-198
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• 2020

Root extension is the most important growth change that occurs during cultivation. We analyzed growth changes according to young seedling age, temperature, and the degree of root cutting in order to identify factors affecting rooting after transplanting. Root cutting did not affect plant height growth rate, root growth rate was increased in plants that experienced root cutting, and 14-day-old seedlings exhibited a higher growth rate than 7-day-old seedlings. Growth temperature experiments revealed that elongation was high at 25℃ and 28℃, but tended to be low at 18℃, and root elongation was high at 22-28℃ for 7-day-old seedlings and 22-25℃ for 14-day-old seedlings. Nitrogen absorption decreased in the following growth temperature order: 25, 28, 22, 18℃, and differences in nitrogen absorption under different growth temperatures tended to be lower in 7-day-old seedlings. The amount of nitrogen taken up by roots did not differ significantly between the short root treatment and the control, and 7-day-old seedlings tended to start nitrogen absorption faster than 14-day-old seedlings. Root vitality was highest in short-rooted 7-day-old seedlings with 3 cm of root remaining, and vitality also tended to be high in short-rooted 14-day-old seedlings.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.193-199
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• 1999

This study was conducted to establish the standard of quality evaluation in Korean cultivated peony root(Paeoniae Radix). The diameter of fresh root and the concentrations of paeoniflorin, abliflorin and five phenolic compounds at different root ages in Euisung cultivar were investigated. The diameters of fresh root were 5.5mm, 10.3mm, 15.6mm and 19.1mm in one-year, two-year, three-year and four-year-old, respectively. It was also found that the diameter of fresh root was uniformly increased with the increase of root age. The concentrations of paeoniflorin, albiflorin, (+) -catechin and benzoic acid in one-year-old peony root(6.44%, 1.55%, 0.80% and 0.36%, respectively) were higher than those in three-(3.49%, 0.62%, 0.43% and 0.26%) or four-year-old(3.28%, 0.47%, 0.34% and 0.20%). The concentrations of gallic acid, (-) -epicatechin and (+) -taxiforin $3-O-{\beta}-D-glucoside$ were higher in three- (0.26%, 0.09% and 0.26%, respectively) or four-year-old (0.26%, 0.10% and 0.29%) than those in one-year-old (0.25 %, 0.08 % and 0.23 %) by contraries. Excepting (-) -epicatecin, the concentrations of paeoniflorin, albiflorin and four phenolic compounds in the root of unremoved cork layer were higher than those in the root of removed cork layer.