• Journal of the Korean Society of Visualization
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• v.21 no.1
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• pp.12-17
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• 2023

Aortic valve stenosis is a heart valve disease caused by the accumulation of calcium in the valve, which can divide into tricuspid aortic valve (TAV) stenosis and bicuspid aortic valve (BAV) stenosis depending on the shape of natural valve. In this study, pig heart-based TAV and BAV ex vivo models were fabricated, and the flow characteristics behind a valve were analyzed using 4D flow MRI. Flow behind normal TAV was uniformly distributed, while BAV asymmetrically opened with an eccentric strong jet. Especially, BAV ex vivo model exhibited a secondary flow in the region where the valve closed. In addition, BAV had a 26% higher peak velocity while maintaining similar stroke volume compared with normal TAV. This study would be helpful for understanding the flow characteristics for BAV AS patients.

• The Journal of the Korean dental association
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• v.12 no.2
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• pp.107-111
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• 1974

In order to collect some necessary data to promote correcting the toothbrushing technic on the Korean public, the author had examined the number of present teeth on which had cervical abrasion and the most basic home dental care in 2,000 Korean male and female adults from 19 to 52 years in the age. Then, the cervical abrasion experience rate and the cervical abrasion experience teeth rate were calculated and evaluated. The obtained results were as follows: 1. Cervical abrasion experience rate was 32.45% 2. Cervical abrasion experience rate was gradually increased by ageing. 3. Cervical abrasion experience rate in male adults was higher than that in female adults. 4. Cervical abrasion experience rate in the lower jaw was higher than that in the upper jaw. 5. Cervical abrasion experience rate of the teeth at the right side was higher than that of the teeth at the left side. 6. Cervical abrasion experience teeth rate was 3.82%. 7. Cervical abrasion experience rate was highest on the first bicuspid, and followed in the sequence of the second bicuspid, canine, first molar, incisors, and 2nd and 3rd molars.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.413-439
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• 1995

The purpose of this study was to evaluate the stress distribution developed in the supporting structures by mandibular distal extension removable partial dentures with 2 different direct retainer designs and with or without indirect retainer and abutment splinting. The examined direct retainers on the second bicuspid abutment tooth were Akers clasp and RPA clasp, the indirect retainer was located on the mesial fossa of the first bicuspid, and the first and second bicuspid were splinted in case of tooth splinting. Total 8 cases were compared and analyzed with 3-dimensional finite element method. 150N were applied vertically on the artificial teeth of the removable partial denture, and then stress distribution patterns were analyzed and compared. The results were as follows : 1. The forces transmitted to the abutment tooth were primarily from the occlusal rests. 2. The abutment tooth was displaced distally when the force was applied. The compressive stress was observed at the distal root surface of the abutment tooth and the tensile stress, at the mesial root surface. 3. The denture base was displaced posteriorly and inferiorly when the force was applied. At the more distal portion of the denture base, the greater displacement was observed.And the anterior portion of the major connector was displaced superiorly. 4. The occlusal rest placed on the distal part of the abutment tooth tended to tip the tooth more posteriorly than did one on the mesial part of that tooth. 5. Severe superior displacement was observed at the anterior portion of the major connector in case of removable partial dentures without indirect retainer. 6. In case of tooth-splinting, the stress was distributed through all the root surface of both abuments. In case of no tooth-splinting, the stress was concentrated on the distal root surface of the primary abutment.

• Journal of Chest Surgery
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• v.56 no.4
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• pp.255-261
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• 2023

Background: The surgical threshold for bicuspid aortic valve (BAV)-related aortopathy is a matter of debate due to its uncertain etiology and prognosis. This study investigated the prognosis of unrepaired BAV aortopathy in patients undergoing surgical aortic valve replacement (SAVR). Methods: We retrospectively analyzed data from 720 patients (age, 60.8±11.5 years; 246 women) who underwent SAVR for BAV disease without aortic repair between 2005 and 2020 at Asan Medical Center. The clinical endpoints were defined as occurrences of sudden death, aortic dissection or rupture, and elective aortic repair. To estimate postoperative changes in the dimensions of the unrepaired aorta, the individual annual aortic expansion rate was calculated. Multiple linear regression models were used to evaluate the risk of aortic expansion. Results: The mean ascending aortic diameter was 39.5±4.6 mm, and 299 patients (41.5%) had a baseline ascending aorta diameter >40 mm. During 70.0±68.3 months of follow-up, the mean annual aortic expansion rate was 0.39±1.96 mm/yr, no aortic dissection or rupture was observed, and sudden deaths were reported in 12 patients (0.34% per person-year). Linear regression analysis revealed no significant correlation between the baseline ascending aortic diameter and postoperative aortic expansion (R²=0.004, β=-0.84, p=0.082). Conclusion: In selected patients undergoing SAVR for a BAV (<55 mm), the risk of adverse aortic events was very low. As this observation contradicts current practice guidelines advocating for proactive aortic replacement in dilated ascending aortas measuring >45 mm, the study results need further validation by studies involving larger populations or randomized controlled trials.

• Journal of Chest Surgery
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• v.49 no.6
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• pp.443-450
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• 2016

Background: Although unique aortic pathology related to bicuspid aortic valve (BAV) has been previously reported, clinical implications of BAV to aortopathy risk have yet to be investigated. We looked for potential differences in matrix protein expressions in the aortic wall in BAV patients. Methods: Aorta specimens were obtained from 31 patients: BAV group (n=27), tricuspid aortic valve (TAV) group (n=4). The BAV group was categorized into three subgroups: left coronary sinus-right coronary sinus (R+L group; n=13, 42%), right coronary sinus-non-coronary sinus (R+N group; n=8, 26%), and anteroposterior (AP group; n=6, 19%). We analyzed the expression of endothelial nitric oxide synthase (eNOS), matrix metalloproteinase (MMP)-9, and tissue inhibitor of matrix metalloproteinase (TIMP)-2. Results: Based on the mean value of the control group, BAV group showed decreased expression of eNOS in 72.7% of patients, increased MMP-9 in 82.3%, and decreased TIMP in 79.2%. There was a higher tendency for aortopathy in the BAV group: eNOS $(BAV:TAV)=53%{\pm}7%:57%{\pm}11%$, MMP-9 $(BAV:TAV)=48%{\pm}10%:38%{\pm}1%$. The AP group showed lower expression of eNOS than the fusion (R+L, R+N) group did; $48%{\pm}5%$ vs. $55%{\pm}7%$ (p=0.081). Conclusion: Not all patients with BAV had expression of aortopathy; however, for patients who had a suspicious form of bicuspid valve, aortic wall biopsy could be valuable to signify the presence of aortopathy.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.235-248
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• 1997

The purpose of this study was to investigate the width of attached gingiva of 414 subjects with healthy gingiva, or early stage of gingivitis. We compared the differences according to the tooth location, age (Yonger group : $14{\sim}30$, Older group : $31{\sim}67$) and gender. In addition, we compared the width of attached gingiva in the subjects with less than 2 sites of gingival recession($Re{\leq}2$) and the subjects with more than 3 sites of gingival recession($Re{\geq}3$) to study the relationship between the gingival recession and the width of attached gingiva. The results were as follows : 1. The width of keratinized gingiva was widest in maxillary incisors($5.3{\pm}1.4mm$) and narrowest in mandibular right 1st bicuspid and mandibular right and left 2nd molars($3.5{\pm}1.1mm$). 2. The width of attached gingiva was widest in maxillary right central incisor($3.8{\pm}1.5mm$) and narrowest in mandibular right 2nd molar($1.2{\pm}1.0mm$). 3. In the comparison between the age groups, the width of keratinized in older group was significantly (p<0.05) wider than that in younger group in maxillary right and left 1st bicuspids, mandibular right and left 1st and 2nd molars, maxillary right and left cuspids and mandibular right 1st bicuspid. There was no significant difference in the width of attached gingiva between the two groups except for maxillary right and left 1st molars and maxillary left 2nd molar. 4. In the comparison between male group and female group, in maxillary right and and left lateral incisors and cuspids, mandibular right and left cuspids and 1st bicuspids, the width of attached gingiva in female was significantly(p<0.05) wider than that in male group. 5. In the comparison between the Re 3 group and Re 2 group, there was no significant difference except for maxillary right and left 2nd molars and maxillary left 1st molar. 6. The frequency of gingival recession was m the order of mandibular right 1st bicuspid(16.6%), maxillary right 1st bicuspid(13.7%), maxillary and mandibular left 1st bicuspids (13.4%), mandibular left cuspid (10.5%), maxillary left and mandibular right cuspids(10.1%) and maxillary right cuspid(7.9%).

• The Journal of the Korean dental association
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• v.22 no.5 s.180
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• pp.429-438
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• 1984

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1337-1338
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• 2023

• Journal of Chest Surgery
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• v.20 no.2
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• pp.300-308
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• 1987

Clinical and pathologic data were reviewed in 20 patients who had have surgery for isolated aortic valvular heart disease between April 1978 and April, 1987. Hospital mortality was 10%, with no additional late mortality during a mean follow-up period of 24.1 months. Prosthetic valve failure developed in 3 patients and two had reoperation. Niety four percent of the survivors who were in NYHA Funtional class III or IV before operation are now in class I or II. Ninety percent of all patients are still alive at a maximum follow up of 9 years. The clinical histories, gross and histologic examination of valves estabilished the causes for isolated aortic valve disease: 3 rheumatic, 2 congenital bicuspid, 2 hypertention, 2 aortitis and each one case of floppy valve, medial cystic necrosis of aorta, bacterial endocarditis. But etiology was unknown in 8 cases. Sixteen patietns had myxoid degeneration, defined as significant disruption of the valve fibrosa and its replacement by acid mucosaccharides and cystic changes. Myxoid degeneration was also the primary pathologic abnormality in the patients with 2 hypertention, 2 rheumatic, 1 aortitis, 1 bacterial endocarditis, 1 floppy valve, 1 congenital bicuspid. The patients with myxoid degeneration of uncertain origin were 8. Histologic finding of all of them revealed nonspecific patients with myxoid degeneration of uncertain orgin were 8. Histologic finding of all of them revealed nonspecific chronic valvulitis with myxoid degeneration. This finding may indicate that the etiology w uld be infectious.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.167-177
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• 1986

This study was undertaken to compare the main differences and its effects of the 4 first bicuspid extraction on the face and dental arch of the class II div 1 malocclusion. The subjects consisted of twenty two class II div 1 malocclusion, four males, eighteen females, were 14 Years 2 Months old at the stan of the treatment 16 Year 3 Months old at the end of the treatment. (mean age) Twenty one variables were observed by comparing the statistical data of the pretreatment records with postteratment records, which were consited of eight varibles on the study model digitation, thirteen variables on the tracing of the lateral cephalogram. The following results were obtained. 1. No significant change was observed in the intercanine width. 2. Intercuspal widths of the 1st. premolar and 2nd. premolar were decreased. 3. Change of the overjet was dependant upon upper anterior rather than lower anterior. 4. No significant changes were observed in facial plane angle and ANB angle. 5. Uprighting of the lower 1st. molar had an effect on the increase of the facial height.