1.A comparative study on the fit and screw joint stability of ready-made abutment and CAD-CAM custom-made abutment.
Jong Wook KIM ; Yu Ri HEO ; Hee Jung KIM ; Chae Heon CHUNG
The Journal of Korean Academy of Prosthodontics 2013;51(4):276-283
PURPOSE: The purpose of this study was to investigate the fit and screw joint stability between Ready-made abutment and CAD-CAM custom-made abutment. MATERIALS AND METHODS: Osstem implant system was used. Ready-made abutment (Transfer abutment, Osstem Implant Co. Ltd, Busan, Korea), CAD-CAM custom-made abutment (CustomFit abutment, Osstem Implant Co. Ltd, Busan, Korea) and domestically manufactured CAD-CAM custom-made abutment (Myplant, Raphabio Co., Seoul, Korea) were fabricated five each and screws were provided by each company. Fixture and abutments were tightening with 30Ncm according to the manufacturer's instruction and then preloding reverse torque values were measured 3 times repeatedly. Kruskal-Wallis test was used for statistical analysis of the preloading reverse torque values (alpha=.05). After specimens were embedded into epoxy resin, wet cutting and polishing was performed and FE-SEM imaging was performed, on the contact interface. RESULTS: The pre-loading reverse torque values were 26.0 +/- 0.30 Ncm (ready-made abutment; Transfer abutment) and 26.3 +/- 0.32 Ncm (CAD-CAM custom-made abutment; CustomFit abutment) and 24.7 +/- 0.67 Ncm (CAD-CAM custom-made abutment; Myplant). The domestically manufactured CAD-CAM custom-made abutment (Myplant abutment) presented lower pre-loading reverse torque value with statistically significant difference than that of the ready-made abutment (Transfer abutment) and CAD-CAM custom-made abutment (CustomFit abutment) manufactured from the same company (P=.027) and showed marginal gap in the fixture-abutment interface. CONCLUSION: Within the limitation of the present in-vitro study, in domestically manufactured CAD-CAM custom-made abutment (Myplant abutment) showed lower screw joint stability and fitness between fixture and abutment.
Computer-Aided Design*
;
Torque
2.Single-center experience of the Korean-Developmental Screening Test for infants and children.
Chae Ri SUH ; Su Ye SOHN ; Gun Ha KIM ; Seong Kwan JUNG ; Baik Lin EUN
Korean Journal of Pediatrics 2016;59(12):483-489
PURPOSE: We investigated the number of test takers of the Korean-Developmental Screening Test (K-DST) in a single children's hospital within a year, according to age, referral rate, and follow-up percentage. METHODS: For this study, 4,062 children who visited and received K-DST at Woorisoa Children's Hospital between January and December 2015 were enrolled. Seven test sets were used according to the Korean National Health Screening Program for infants and children in the following age groups: 4 to 6, 9 to 12, 18 to 24, 30 to 36, 42 to 48, 54 to 60, and 66 to 71 months. The results of the K-DST were categorized into 4 groups as follows: further evaluation (<−2 standard deviation [−2SD]), follow-up test (−2SD to −1SD), peer level (−1SD to 1SD), and high level (>1SD). RESULTS: The test participants' population and follow-up population were concentrated before the age of 24 months (2,532, 62.3%). The children most commonly referred for further evaluation were those in the 30- to 41-month age group. A mismatch was found between the results of the K-DST and the additional questions. Most of the infants and children with suspicious developmental delays showed catch-up development in their follow-up tests (43 of 55, 78.2%). CONCLUSION: The use of K-DST should be encouraged, especially among children aged over 24 months. Multiple-choice question format for the additional questions is recommended to avoid confusion. We suggest a nationwide study to evaluate and revise the K-DST.
Child*
;
Follow-Up Studies
;
Humans
;
Infant*
;
Korea
;
Mass Screening*
;
Referral and Consultation
3.Torsion of the Isolated Fallopian Tube in an Adolescence: A Case Report.
Yeon Hee KU ; Jin A KIM ; Chae Hyung LEE ; Kwang Bum BAE ; Hye Won JEON ; Gyu Ri HWANG
Korean Journal of Obstetrics and Gynecology 2006;49(5):1154-1157
Torsion of the fallopian tube is an uncommon cause for acute low abdominal pain in female that is difficult to diagnose. Because it has no pathognomonic clinical symptoms or laboratory findings, a high index of suspicion is important when there is history of pelvic pathologic conditions or surgery. The early diagnosis and surgical treatment of the disease are mandatory to preserve oviduct.
Abdominal Pain
;
Adolescent*
;
Animals
;
Early Diagnosis
;
Fallopian Tubes*
;
Female
;
Humans
;
Oviducts
4.Palatal obturator restoration of a cleft palate patient with velopharyngeal insufficiency: a clinical report.
Yu Ri HEO ; Jong Wook KIM ; Gyeong Je LEE ; Chae Heon CHUNG
The Journal of Korean Academy of Prosthodontics 2013;51(4):353-360
Cleft lip and palate is congenital deformity in oral and maxillofacial area. Normal soft palate has velopharyngeal closure action by connecting oral cavity and nasal cavity at rest and moving upward at swallowing and specific pronunciation. Cleft palate patients with velopharyngeal insufficiency have difficulty in mastication, swallowing and pronunciation because velopharyngeal closure is incomplete. At this time, a prosthetic device used to cover palate defects is called a palatal obturator. A palatal obturator separates oral cavity and nasal cavity and recovers pronunciation, mastication, swallowing and esthetic function. The purpose of this case study is to report the results because it reaches a satisfactory result in functional and esthetic aspects through functional impression procedures using modeling compound and tissue conditioner for restoration of a cleft palate patient with velopharyngeal insufficiency.
Cleft Lip
;
Cleft Palate*
;
Congenital Abnormalities
;
Deglutition
;
Humans
;
Mastication
;
Mouth
;
Nasal Cavity
;
Palatal Obturators*
;
Palate
;
Palate, Soft
;
Velopharyngeal Insufficiency*
5.Effect of Bio-Oss grafts on tooth eruption: an experimental study in a canine model.
Jihun KIM ; Chae Ri CHANG ; Byung Ho CHOI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2010;36(6):528-532
INTRODUCTION: There are few reports on tooth eruption through Bio-Oss grafts. To our knowledge, there are no reports on whether teeth can erupt normally through the grafts. The aim of this study was to examine the effect of Bio-Oss grafts on tooth eruption in a canine model. MATERIALS AND METHODS: In five 10-week-old dogs, the deciduous third mandibular molars in one jaw quadrant of each animal were extracted and the fresh extraction sockets were then filled with Bio-Oss particles (experimental side). No such treatments were performed on the contralateral side (control side). A clinical and radiological evaluation was carried out every other week to evaluate the eruption level of the permanent third mandibular premolars and compare the eruption levels between the two sides. RESULTS: At week 4 after the experiment, the permanent third premolars began to erupt on both sides. At week 12, the crown of the permanent third premolar emerged from the gingiva on both sides. At week 20, the permanent third premolars on both sides erupted enough to occlude the opposing teeth. No significant differences were found between the control and experimental sides in terms of the eruption speed of the permanent third molars. CONCLUSION: These findings demonstrate that the grafting of Bio-Oss particles into the alveolar bone defects does not affect tooth eruption.
Animals
;
Bicuspid
;
Cleft Lip
;
Cleft Palate
;
Crowns
;
Dogs
;
Gingiva
;
Jaw
;
Minerals
;
Molar
;
Tooth
;
Tooth Eruption
;
Tooth Movement
;
Transplants
6.Reduction of Inter-Rater and Intra-Rater Variability in Psoriasis Area and Severity Index Assessment by Photographic Training.
Sang Woong YOUN ; Chong Won CHOI ; Bo Ri KIM ; Je Byeong CHAE
Annals of Dermatology 2015;27(5):557-562
BACKGROUND: Severity grading is important for the assessment of psoriasis treatment efficacy. This is most commonly achieved by using the psoriasis area and severity index (PASI), a subjective tool with inherent inter-rater and intra-rater variability. PASI-naive dermatologists require training to properly conduct a PASI assessment. OBJECTIVE: In the present study, we aimed to investigate whether photographic training improves inter-rater and intra-rater variabilities. We also determined which PASI component has the greatest impact on variability. METHODS: Twenty-one dermatologists received 1 hour of PASI training. They were tested before and after the training to evaluate intra-rater variability. The physicians were further tested after training by using a reference photograph. RESULTS: The mean of each PASI component was underevaluated compared with scoring by a PASI expert. The concordance rate with the expert's grading was highest for thickness followed by erythema, scaling, and area. The scaling score showed the greatest improvement after training. After training, the distribution of deviation from the expert's grading, which signifies inter-rater variability, improved only for the PASI area component. The deviation of scaling grading improved upon retesting by using a reference photograph. CONCLUSION: PASI assessment training improved variabilities to some degree but not for every PASI component. The development of an objective psoriasis severity assessment tool will help overcome the subjective variabilities in PASI assessment, which can never be completely eliminated via training.
Body Surface Area
;
Education
;
Erythema
;
Psoriasis*
;
Severity of Illness Index
;
Treatment Outcome
7.Reduction of Inter-Rater and Intra-Rater Variability in Psoriasis Area and Severity Index Assessment by Photographic Training.
Sang Woong YOUN ; Chong Won CHOI ; Bo Ri KIM ; Je Byeong CHAE
Annals of Dermatology 2015;27(5):557-562
BACKGROUND: Severity grading is important for the assessment of psoriasis treatment efficacy. This is most commonly achieved by using the psoriasis area and severity index (PASI), a subjective tool with inherent inter-rater and intra-rater variability. PASI-naive dermatologists require training to properly conduct a PASI assessment. OBJECTIVE: In the present study, we aimed to investigate whether photographic training improves inter-rater and intra-rater variabilities. We also determined which PASI component has the greatest impact on variability. METHODS: Twenty-one dermatologists received 1 hour of PASI training. They were tested before and after the training to evaluate intra-rater variability. The physicians were further tested after training by using a reference photograph. RESULTS: The mean of each PASI component was underevaluated compared with scoring by a PASI expert. The concordance rate with the expert's grading was highest for thickness followed by erythema, scaling, and area. The scaling score showed the greatest improvement after training. After training, the distribution of deviation from the expert's grading, which signifies inter-rater variability, improved only for the PASI area component. The deviation of scaling grading improved upon retesting by using a reference photograph. CONCLUSION: PASI assessment training improved variabilities to some degree but not for every PASI component. The development of an objective psoriasis severity assessment tool will help overcome the subjective variabilities in PASI assessment, which can never be completely eliminated via training.
Body Surface Area
;
Education
;
Erythema
;
Psoriasis*
;
Severity of Illness Index
;
Treatment Outcome
8.Comparison of fatigue fracture strength by fixture diameter of mini implants.
Yu Ri HEO ; Mee Kyoung SON ; Hee Jung KIM ; Han Cheol CHOE ; Chae Heon CHUNG
The Journal of Korean Academy of Prosthodontics 2012;50(3):156-161
PURPOSE: This study was conducted to obtain difference in fracture strength according to the diameter of one-body O-ring-type of mini implant fixture, to determine the resistance of mini implant to masticatory pressure, and to examine whether overdenture using O-ring type mini implant is clinically usable to maxillary and mandibular edentulous patients. MATERIALS AND METHODS: For this study, 13 mm long one body O-ring-type mini implants of different diameters (2.0 mm, 2.5 mm and 3.0 mm) (Dentis, Daegu, Korea) were prepared, 5 for each diameter. The sample was placed at 30degrees from the horizontal surface on the universal testing machine, and off-axis loading was applied until permanent deformation occurred and the load was taken as maximum compressive strength. The mean value of the 5 samples was calculated, and the compressive strength of implant fixture was compared according to diameter. In addition, we prepared 3 samples for each diameter, and applied loading equal to 80%, 60% and 40% of the compressive strength until fracture occurred. Then, we measured the cycle number on fracture and analyzed fatigue fracture for each diameter. Additionally, we measured the cycle number on fracture that occurred when a load of 43 N, which is the average masticatory force of complete denture, was applied. The difference on compressive strength between each group was tested statistically using one-way ANOVA test. RESULTS: Compressive strength according to the diameter of mini implant was 101.5 +/- 14.6 N, 149 +/- 6.1 N and 276.0 +/- 13.4 N, respectively, for diameters 2.0 mm, 2.5 mm and 3.0 mm. In the results of fatigue fracture test at 43 N, fracture did not occur until 2x106 cycles at diameter 2.0 mm, and until 5x106 cycles at 2.5 mm and 3.0 mm. CONCLUSION: Compressive strength increased significantly with increasing diameter of mini implant. In the results of fatigue fracture test conducted under the average masticatory force of complete denture, fracture did not occur at any of the three diameters. All of the three diameters are usable for supporting overdenture in maxillary and mandibular edentulous patients, but considering that the highest masticatory force of complete denture is 157 N, caution should be used in case diameter 2.0 mm or 2.5 mm is used.
Bite Force
;
Collodion
;
Compressive Strength
;
Denture, Complete
;
Denture, Overlay
;
Fatigue
;
Fractures, Stress
;
Humans
9.Contour of lingual surface in lower complete denture formed by polished surface impression.
Yu Ri HEO ; Hee Jung KIM ; Mee Kyoung SON ; Chae Heon CHUNG
The Journal of Advanced Prosthodontics 2016;8(6):472-478
PURPOSE: The aim of this study was to analyze the shapes of lingual polished surfaces in lower complete dentures formed by polished surface impressions and to provide reference data for use when manufacturing edentulous trays and lower complete dentures. MATERIALS AND METHODS: Twenty-six patients with mandibular edentulism were studied. After lower wax dentures were fabricated, wax was removed from the lingual side of the wax denture and a lingual polished surface impression was obtained with tissue conditioner. The definitive denture was scanned with a three-dimensional scanner, and scanned images were obtained. At the cross-sections of the lingual frenum, lateral incisors, first premolars, first molars, and anterior border of the retromolar pads, three points were marked and eight measurements were taken. The Kruskal-Wallis test and a post hoc analysis with the Mann-Whitney test were performed. RESULTS: Each patient showed similar values for the same areas on the left and right sides without a statistically significant difference. The height of the contour of the lingual polished surface at the lingual frenum was halfway between the occlusal plane and lingual border, it moved gradually in a downward direction. The angle from the occlusal plane to the height of the contour of the lingual polished surface was increased as it progressed from the lingual frenum towards the retromolar pads. CONCLUSION: The shape of the mandibular lingual polished surface was convex at the lingual frenum, lateral incisors and gradually flattened towards the first molars and retromolar pads.
Bicuspid
;
Dental Occlusion
;
Denture, Complete*
;
Dentures
;
Humans
;
Incisor
;
Lingual Frenum
;
Molar
10.A Case of Chronic Neuropathic Pseudo-obstruction of the Colon.
Sunyong KIM ; Min Kyung KIM ; Uk JO ; Jung Min CHAE ; Jae Myung CHA ; A Ri SHIN ; Sung Jig LIM ; Ahrim MOON
Korean Journal of Gastrointestinal Endoscopy 2011;42(3):179-184
Colonic pseudo-obstruction, which is characterized by repetitive episodes or continuous symptoms and signs of a bowel obstruction, is a rare disease that results in colorectal dilatation without any obstructing lesions. Cases with neuropathic chronic colonic pseudo-obstruction have rarely been reported in Korea. We report a case of neuropathic colonic pseudo-obstruction, which results in decreased number of interstitial cells of Cajal and hypoganglionosis, in a 50-year-old man with chronic constipation accompanied by megacolon.
Colon
;
Colonic Pseudo-Obstruction
;
Constipation
;
Dilatation
;
Humans
;
Interstitial Cells of Cajal
;
Korea
;
Megacolon
;
Middle Aged
;
Rare Diseases