1.One-visit Apexification Using MTA and Reattachment of a Crown-root Fractured Tooth with Severe Coronal Damage: A Case Report
Youngjun PARK ; Jewoo LEE ; Jiyoung RA
Journal of Korean Academy of Pediatric Dentistry 2018;45(4):521-527
In dental trauma, reattachment of the original tooth fragment improves the reproduction of original tooth shape, texture, color, and radiolucency; thus, it provides good aesthetics.A 9-year-old boy was referred due to complicated crown-root fracture of the maxillary right central incisor. Although it had poor prognosis due to severe coronal damage and subcrestal fracture, reattachment of the tooth fragment was chosen due to the patient's age. One-visit apexification with mineral trioxide aggregate (MTA) was performed, followed by osteotomy and reattachment of the tooth fragment with post placement.Regular observation revealed no clinical signs or symptoms and no radiologic complications.
Apexification
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Child
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Esthetics
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Humans
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Incisor
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Male
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Miners
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Osteotomy
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Pemetrexed
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Prognosis
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Reproduction
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Tooth
2.Evaluation of High-power Light Emitting Diode Curing Light on Sealant Polymerization
Youngjun PARK ; Jewoo LEE ; Jiyoung RA
Journal of Korean Academy of Pediatric Dentistry 2019;46(1):57-63
This study aimed to determine whether the curing times of Xtra Power and High Power modes of high-power light emitting diode (LED) curing light are sufficient for polymerization of resin sealants. The specimens were prepared and their microhardness values were measured and compared with those of specimens polymerized under conventional LED curing light.The filled sealant polymerized for 8 seconds in the High Power mode and for 3 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000). The unfilled sealant polymerized for 8, 12 seconds in the High Power mode and for 6 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000).The results of this study suggest that the short curing time with the Xtra Power and High Power modes of highpower LED curing light are not sufficient for adequate polymerization of sealants under specific conditions, taking into account the curing times and the type of sealant.
Polymerization
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Polymers
3.Expression of alpha1 Receptor and Nitric Oxide Synthase in Oophorectomized and Estrogen-Supplemented Rat Bladder and Urethra.
Youngjun SEO ; Sung Woo PARK ; Joo Yeong KIM ; Sang Don LEE
Korean Journal of Urology 2014;55(10):677-686
PURPOSE: To investigate the effects of estrogen on the expression of the alpha1 receptor and nitric oxide synthase (NOS) in rat urethra and bladder after oophorectomy. MATERIALS AND METHODS: Forty-five mature female Sprague-Dawley rats (aged 10-11 weeks, 235-250 g) were randomly assigned to one of three groups: control group, oophorectomy group (Opx), or oophorectomy and estradiol replacement group (Opx+ Est). The degree of expression of alpha1 receptor (alpha1A and D) and NOS (neuronal NOS [nNOS] and endothelial NOS [eNOS]) in bladder and urethral tissues was investigated by using immunohistochemical staining and Western blotting. RESULTS: In the bladder, the expression rates of alpha1 receptor (alpha1A and alpha1D) increased in the Opx group but decreased in the Opx+Est group. These changes were not statistically significant. The alpha1A and alpha1D receptor of the urethra decreased in the Opx group but increased in the Opx+Est group. These changes were not statistically significant. In the bladder and urethra, the expression rates of nNOS and eNOS significantly increased in the Opx group but decreased in the Opx+Est group (p<0.05). CONCLUSIONS: These data suggest that estrogen depletion increases NOS and alpha1 receptor expression in the rat bladder. However, these changes could be restored by estrogen replacement therapy.
Animals
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Collagen/metabolism
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Estradiol/analogs & derivatives/blood/pharmacology
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Estrogen Replacement Therapy/*methods
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Female
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Muscle, Smooth/pathology
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Nitric Oxide Synthase/*metabolism
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Ovariectomy
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Rats, Sprague-Dawley
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Receptors, Adrenergic, alpha-1/*metabolism
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Urethra/drug effects/*metabolism/pathology
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Urinary Bladder/drug effects/*metabolism/pathology
4.Distribution of Asymmetrical Hearing Loss Among the Workers participated in Noise-specific Health Examination.
Youngjun KWON ; Kyungrae KIM ; Soo Jin LEE ; Jaechul SONG
Korean Journal of Occupational and Environmental Medicine 1999;11(3):361-372
OBJECTIVES: Noise-induced hearing lose(NIHL) is characterized by bilaterally symmetrical hearing loss, but some screening audiometries of employees who were exposed noise showed asymmetry. Therefore, this study was carried out to evaluate distribution of asymmetrical hearing loss and factors influencing asymmetries. METHODS: Study subjects were 294 male employees who have participated in 1st and 2nd noise-specific health examination. RESULTS: The interaural threshold difference of 20 dB or more at 4,000 Hz was classified as asymmetry. Among 294 NIHL employees. 19% had left asymmetric hearing loss. 22% had right asymmetric hearing loss. and overall asymmetry were 41%. Prevalence of asymmetry at 4,000 Hz significantly more decreased in middle(80~84 dB (A)) and high-level noise exposure groups(> or =85 dB(A)) than low-level exposure group and significantly increased as greater hearing threshold level in the worse ear. Prevalence of left asymmetry at 4,000 Hz significantly increased as greater hearing threshold level in the worse ear than right asymmetry. The interaural difference was significantly greater in the left asymmetry. CONCLUSIONS: Noise exposure produced asymmetric hearing loss(interaural asymmetry was 20 dB and more in 41% of case) and left ear was more susceptible to noise demage than right ear.
Audiometry
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Ear
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Hearing Loss*
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Hearing*
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Humans
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Male
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Mass Screening
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Noise
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Prevalence
5.Projected lifetime cancer risk from cone-beam computed tomography for orthodontic treatment
Nayansi JHA ; Yoon-Ji KIM ; Youngjun LEE ; Ju Young LEE ; Won Jin LEE ; Sang-Jin SUNG
The Korean Journal of Orthodontics 2021;51(3):189-198
Objective:
To estimate the projected cancer risk attributable to diagnostic cone-beam computed tomography (CBCT) performed under different exposure settings for orthodontic purposes in children and adults.
Methods:
We collected a list of CBCT machines and their specifications from 38 orthodontists. Organ doses were estimated using median and maximum exposure settings of 105 kVp/156.8 mAs and 130 kVp/200 mAs, respectively. The projected cancer risk attributable to CBCT procedures performed 1–3 times within 2 years was calculated for children (aged 5 and 10 years) and adult (aged 20, 30, and 40 years) male and female patients.
Results:
For maximum exposure settings, the mean lifetime fractional ratio (LFR) was 14.28% for children and 0.91% for adults; this indicated that the risk to children was 16 times the risk to adults. For median exposure settings, the mean LFR was 5.25% and 0.58% for children and adults, respectively. The risk of cancer decreased with increasing age. For both median and maximum exposure settings, females showed a higher risk of cancer than did males in all age groups. Cancer risk increased with an increase in the frequency of CBCT procedures within a given period.
Conclusions
The projected dental CBCT-associated cancer risk spans over a wide range depending on the machine parameters and image acquisition settings. Children and female patients are at a higher risk of developing cancer associated with diagnostic CBCT. Therefore, the use of diagnostic CBCT should be justified, and protective measures should be taken to minimize the harmful biological effects of radiation.
6.Projected lifetime cancer risk from cone-beam computed tomography for orthodontic treatment
Nayansi JHA ; Yoon-Ji KIM ; Youngjun LEE ; Ju Young LEE ; Won Jin LEE ; Sang-Jin SUNG
The Korean Journal of Orthodontics 2021;51(3):189-198
Objective:
To estimate the projected cancer risk attributable to diagnostic cone-beam computed tomography (CBCT) performed under different exposure settings for orthodontic purposes in children and adults.
Methods:
We collected a list of CBCT machines and their specifications from 38 orthodontists. Organ doses were estimated using median and maximum exposure settings of 105 kVp/156.8 mAs and 130 kVp/200 mAs, respectively. The projected cancer risk attributable to CBCT procedures performed 1–3 times within 2 years was calculated for children (aged 5 and 10 years) and adult (aged 20, 30, and 40 years) male and female patients.
Results:
For maximum exposure settings, the mean lifetime fractional ratio (LFR) was 14.28% for children and 0.91% for adults; this indicated that the risk to children was 16 times the risk to adults. For median exposure settings, the mean LFR was 5.25% and 0.58% for children and adults, respectively. The risk of cancer decreased with increasing age. For both median and maximum exposure settings, females showed a higher risk of cancer than did males in all age groups. Cancer risk increased with an increase in the frequency of CBCT procedures within a given period.
Conclusions
The projected dental CBCT-associated cancer risk spans over a wide range depending on the machine parameters and image acquisition settings. Children and female patients are at a higher risk of developing cancer associated with diagnostic CBCT. Therefore, the use of diagnostic CBCT should be justified, and protective measures should be taken to minimize the harmful biological effects of radiation.
7.Risk Factors of Syme Amputation in Patients with a Diabetic Foot.
Heuichul GWAK ; Jeongyo KIM ; Youngjun KIM ; Jeonghan LEE ; Woonseong LEE
Journal of Korean Foot and Ankle Society 2016;20(2):78-83
PURPOSE: This study examined the factors affecting the treatment of diabetes mellitus foot patients who had undergone a Syme amputation. MATERIALS AND METHODS: This study included 17 patients diagnosed with a diabetes mellitus foot and who had undergone a Syme amputation from January 2010 to January 2014. Some of the risk factors (age, body mass index [BMI], disease duration, smoking, ankle brachial index [ABI], HbA1c, serum albumin, total lymphocyte, C-reactive protein [CRP], and serum creatine) that affect the successful Syme amputation were analyzed. RESULTS: The healing rate of a Syme amputation was significantly higher when the lymphocyte count was above 1,500 mm3 (p=0.029). The factors affecting the surgical outcome according to multivariate analysis were HbA1c and the BMI (p=0.014, p=0.013). Regarding reamputation, there was a significant difference with HbA1c, lymphocyte, and BMI (p=0.01, p=0.03, and p=0.01). No significant differences were observed with age, disease duration of diabetes mellitus, smoking, ABI, serum albumin, CRP, and serum creatine. CONCLUSION: The HbA1c level, BMI and total lymphocyte count are risk factors that must be considered for successful Syme amputation in patients with diabetic foot disease.
Amputation*
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Ankle Brachial Index
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Body Mass Index
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C-Reactive Protein
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Creatine
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Diabetes Mellitus
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Diabetic Foot*
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Foot
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Humans
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Lymphocyte Count
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Lymphocytes
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Multivariate Analysis
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Risk Factors*
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Serum Albumin
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Smoke
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Smoking
8.Surface Characteristics and Biocompatibility of Titanium Coated with Dentin-derived Hydroxyapatite.
Hae Jin KIM ; Mee Kyung SON ; Kyung Ku LEE ; Bo Ah LEE ; Young Joon KIM
International Journal of Oral Biology 2012;37(1):9-16
The aim of this study was to evaluate surface characteristics and biological properties of the dentin-derived hydroxyapatite (HA) coating on titanium substrate. Dentin-derived HA was obtained from extracted human teeth using a calcination method at 850degrees C. The commercially pure titanium (cp-Ti, ASTM Grade II) was used as a metallic substrate and a radio frequency magnetron sputtering method was employed as a coating method. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were utilized to investigate the coating aspects and composition. Atomic forced microscopy (AFM) and a surface profiler were used to assess the surface morphology and roughness. Corrosion tests were performed in phosphate-buffered saline at a 36.5 +/- 1degrees C in order to determine the corrosion behavior of the uncoated and coated specimens. The biocompatibility of dentin-derived HA coated specimens with fetal rat calvarial cells and human gingival fibroblasts was assessed by SEM and cell proliferation analysis. The results showed that the dentin-derived HA coatings appeared to cover thinly and homogeneously the surfaces without changing of the titanium substrate. The EDX analysis of this the coating surface indicated the presence of Ca and P elements. The mean surface roughness of cp-Ti and dentin-derived coating specimens was 0.27 microm and, 1.7 microm, respectively. Corrosion tests indicated a stable passive film of the dentin-derived HA coating specimens. SEM observations of fetal rat calvarial cells and human fibroblast cells on coated surfaces showed that the cells proliferated and developed a network of dense interconnections. The cells on all specimens proliferated actively within the culture period, showing good cell viability. At day 1 and 3, dentin-derived coating specimens showed 89% and 93% cell viability, respectively, when normalized to cp-Ti specimens. These results suggest that dentin-derived HA coating using the RF magnetron sputtering method has good surface characteristics and biocompatibility.
Animals
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Cell Proliferation
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Cell Survival
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Corrosion
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Durapatite
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Fibroblasts
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Humans
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Microscopy
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Microscopy, Electron, Scanning
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Rats
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Titanium
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Tooth
9.The Prostate Cancer Patient Had Higher C-Reactive Protein Than BPH Patient.
Youngjun KIM ; Yongseok JEON ; Hana LEE ; Donghyun LEE ; Bongsuk SHIM
Korean Journal of Urology 2013;54(2):85-88
PURPOSE: C-reactive protein (CRP) is a general marker for inflammation and it has been associated with prostate cancer. We hypothesized that a correlation may exist between CRP and prostate cancer in patients undergoing transrectal biopsy of the prostate because of rising prostate-specific antigen (PSA) levels. MATERIALS AND METHODS: From January 2009 to March 2012, we retrospectively reviewed 710 patients who visited our urology department and were diagnosed as having a PSA value over 4.0 ng/mL. Patients with acute infections, rheumatoid arthritis, gout, asthma, chronic lung disease, myocardial infarction, or apoplexy and those who had taken nonsteroidal anti-inflammatory drugs were exempted from the research because these variables could have impacted CRP. After we applied the exclusion criteria, we selected 63 patients with prostate cancer and 140 patients with benign prostatic hyperplasia (BPH). RESULTS: A total of 203 patients were observed: 140 patients had BPH, and 63 patients had prostate cancer. Prostate cancer patients were divided into two groups by tumor-node-metastasis classification. The patients below T2 were group A, and those above T3 were group B. The natural logarithm of C-reactive protein (lnCRP) differed between the BPH group and the prostate cancer group. The lnCRP also differed between the BPH group and prostate cancer groups A and B (p<0.05). CONCLUSIONS: The serum CRP level of the prostate cancer group was higher than that of the BPH group. Inflammation may be correlated with prostate cancer according to the serum CRP level.
Arthritis, Rheumatoid
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Asthma
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Biopsy
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C-Reactive Protein
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Gout
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Humans
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Inflammation
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Lung Diseases
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Myocardial Infarction
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Prostate
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Prostate-Specific Antigen
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Prostatic Hyperplasia
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Prostatic Neoplasms
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Retrospective Studies
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Stroke
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Urology