1.The Esthetic Upper Incisor Position in Korean Adult Female.
Bo Young YOO ; Hyun Shik HWANG ; Jong Chul KIM
Korean Journal of Physical Anthropology 1994;7(2):219-229
Esthetic is one of the prime goal of the orthodontic treatment. The upper incisor position in important because it is decisive in balanced smile. This study was attempted to obtain the standards and equations on the esthetic upper incisor position. Lateral cephalometric radiographs of 66 Korean young adult females who were candidates of Miss Korea Beauty Contest were traced, measured and statistically analyzed. The results were as follows ; 1. The mean and standard deviation of the measurement for upper incisor position were obtained in the Korean Beauty. 2. Among the measurements of the axis of upper incisor, 1 to SN and 1 to FH were high1y correlated with FH-MP, ANB, FH-N Pag, Y-axis, but 1 to SN (Is-Pr) to present axial inclination of labial surface of upper Incisor didn't have any correlation with the measurements for dentofacial pattern. 3. Among the measurements for the vertical position of upper incisor, 1 to stom had low correlation with to measurements for dentofacial pattern and 1 to PP(mm) was highly correlated with the measurements for facial growth direction. 4. Sixteen multiple regression equations were established to predict upper incisor position balancing with dentofacial pattern. 5. It does not have much power of persuasion to predict esthetic upper incisor position from the measurements for dentofacial pattern.
Adult*
;
Beauty
;
Female*
;
Humans
;
Incisor*
;
Korea
;
Persuasive Communication
;
Young Adult
2.Change of shear bond strength of orthodontic brackets acording to surface treatment on dental gold alloy.
Ji Hyun MIN ; Hyeon Shik HWANG ; Jong Chul KIM
Korean Journal of Orthodontics 2000;30(4):483-490
The dental gold alloy shows a lower bond strength than the natural teeth in bracket bonding, and this can be a possible source of subsequent bond failure. This study aims to evaluate the effect of various gold alloy surface treatment techniques on shear bond strength between the orthodontic adhesives and the gold alloy and to find ways of increasing the bond strength. Two hundred and forty specimens made of the dental gold alloy were divided into twelve groups based on the combination of surface treatment methods(non-surface treatment, sandblasted, sandblasted plus tin-plated, and sandblasted plus intermediate adhesive) and adhesive systems (Ortho-one, Panavia 21, Superbond C&B). The specimens with bonded brackets were placed in distilled water at 37degrees C for 24 hours and shear bond strength was measured by a universal testing machine. The results were as follows: 1. All surface-treated groups showed a significantly higher shear bond strength than non-surface-treated groups. 2. The sandblasted plus tin-plated grout showed a significantly higher shear bond strength than the sandblasted group only when Panavia 21 was involved. 3. The sandblasted plus intermediate adhesive group showed a significantly higher shear bond strength than sandblasted group regardless of the type of adhesive used. 4. Of.the three resin adhesive types, the Superbond C&B showed the highest bond strength, followed by Panavia 21 and Ortho-one. These findings suggest that a combination of sandblasting and intermediate resin treatment is desirable in order to enhance bracket bond strength regardless of adhesive types.
Adhesives
;
Alloys*
;
Dental Cements
;
Orthodontic Brackets*
;
Tooth
;
Water
3.Frontal cephalogram study on the natural head position of facial asymmetry patients.
Korean Journal of Orthodontics 2000;30(5):535-542
The purpose of this study was to find the characteristics of the frontal natural head position(NHP) of patients with facial asymmetry, and to contribute to the diagnosis of facial asymmetry in the clinical examination of orthodontic patients. Twenty adult patients who had apparent facial asymmetry and no severe sagittal skeletal discrepancy were selected as the asymmetry group, and 21 young adults who had symmetric faces were selected as the symmetry group. Frontal cephalograms were obtained in the state of NHP using a pivot-mounted fluid level device. The degree of the menton deviation was defined as the angle between the line drawn through crista galli and anterior nasal spine and the line drawn through crista galli and menton. The following angles were measured and each of them was compared with the degree of the menton deviation: one is the angle between the true vertical line and the supra-orbital line which is a tangent line to the extreme cranial point on the supra-orbital margin, and the other is the angle between the true vertical line and the cervical line drawn through the midpoint of atlas and the 4th cervical vertebra. Through the statistical analysis, following results were obtained. 1. The angle between the supra-orbital line and the true vertical line was much more deviated from the right angle in the asymmetry group than in the symmetry group. 2. The angle between the cervical line and the true vertical line in the asymmetry group showed greater tendency than in the symmetry group, but the difference was not statistically significant. 3. In the asymmetry group, the degree of the menton deviation was positively correlated with the angle between the supra-orbital line and the true vertical line. The above results suggest that facial asymmetry patients show the tendency to have the tilted NHP to compensate the deviation of menton position.
Adult
;
Diagnosis
;
Facial Asymmetry*
;
Head*
;
Humans
;
Spine
;
Young Adult
4.The effects of ipriflavone on the periodontal reorganization following experimental tooth movement in the rat.
Ji Hyun MIN ; Jin Hyoung CHO ; Ki Heon LEE ; Hyeon Shik HWANG
Korean Journal of Orthodontics 2008;38(5):347-357
OBJECTIVE: The purpose of this study was to examine the effect of ipriflavone on periodontal reorganization and prevention of relapse following tooth movement. METHODS: Orthodontic rubber bands were inserted between the first and second maxillary molars of 27 white male rats for 3 weeks for experimental tooth movement. From one day before the removal of orthodontic rubber band, ipriflavone was administered 50 or 400 mg/kg daily in each experimental group whereas carboxymethyl cellulose solution was administered in the control group. They were sacrificed at the 5, 10, and 15th day from the day of removal of orthodontic rubber bands. The amount of relapse was evaluated by measuring the interdental space, and the extent of periodontal reorganization was compared through histological examination. RESULTS: In case of ipriflavone administration, the amount and velocity of relapse was less and slower compared to the control group. In addition, the ipriflavone group showed more rapid periodontal reorganization compared to the control group. CONCLUSIONS: The results of the present study suggest that ipriflavone administration can be used effectively in the prevention of relapse following orthodontic tooth movement through the acceleration of periodontal reorganization.
Acceleration
;
Animals
;
Carboxymethylcellulose Sodium
;
Humans
;
Isoflavones
;
Male
;
Molar
;
Rats
;
Recurrence
;
Rubber
;
Tooth
;
Tooth Movement
5.The Effect of Surface Treatment on Bond Strength of Polycarbonate Bracket.
Seok Pil KIM ; Nyeon Kyeong KIM ; Hyun Jung LEE ; Hyeon Shik HWANG
Korean Journal of Orthodontics 2006;36(5):331-338
OBJECTIVE: The purpose of this study was to evaluate whether the bond strength of polycarbonate brackets can be increased through surface treatment. METHODS: One hundred polycarbonate brackets (Alice) were bonded to bovine incisors with light-cured adhesive. The bracket bases were treated with one of three methods; sandblasting, plastic conditioner application, and combined treatment with sandblasting and plastic conditioner. The brackets without any surface treatment served as the control. The shear bond strength was tested with a universal testing machine, and failure pattern was assessed with the adhesive remnant index. RESULTS: The shear bond strength in all experimental groups was higher than that of the control group (p < 0.001). The group treated with plastic conditioner after sandblasting showed statistically higher shear bond strength than the sandblasting only group (p < 0.05). The group treated with plastic conditioner after sandblasting showed higher shear bond strength than plastic conditioner only group, but the difference was not statistically significant. CONCLUSION: The above results suggest that the surface treatments of polycarbonate bracket is mandatory to improve bond strength, and the most effective method is an application of plastic conditioner after sandblasting.
Adhesives
;
Incisor
;
Plastics
6.Clinical investigation about the result of surgically treated myasthenia gravis.
Dae Hyun KIM ; Eun Gu HWANG ; Kyu Seok CHO ; Bum Shik KIM ; Joo Chul PARK
The Korean Journal of Thoracic and Cardiovascular Surgery 2003;36(1):15-20
BACKGROUND: Myasthenia gravis is a rare autoimmune disease involving acetylcholine receptor and its autoantibody on neuromuscular junction. The methods of treatment are medical treatment and surgical thymectomy. In this paper we analyzed the result of thymectomy and the factors affecting the postoperative symptom improvement. MATERIAL AND METHOD: This study obtained medical records of 37 patients who received the thymectomy for myasthenia gravis from March 1986 to December 1998. RESULT: Out of 37 cases, 21 cases(57%) showed improvement, of which 8 cases (50%) in the group of thymoma(n=16), and 13 cases (62%) in the group of thymic hyperplasia(n=21) showed the improvement of symptoms. Postoperative complications were respiratory insufficiency due to aggravation of symptoms after operation, including tracheal intubation for ventilator support in 9 cases, pneumonia in 3 cases, pneumothorax in 2 cases and left vocal cord palsy in 1 case. There was one postoperative mortality. The relation between postoperative improvement and sex(P=0.3222), age(P=0.7642), thymic pathologic variants,(P=0.4335) and classification of thymoma(P=0.20) showed no statistically significant correlation. However, the lower grade of preoperative symptoms can predict the lower grade of postoperative symptoms significantly(P=0.0032). Follow up study to 36 postoperative survivors was performed in October 2002 based on the out-patient records and call with patients. Out of 36 cases, 33 cases(91.7%) could be investigated and 3 cases could not. Mean follow up period was 83.2 months. Out of 33 cases, 25 cases(75.8%) showed symptomatic improvement, of which 8 cases(53.3%) in the group of thymoma(n=15) and 17 cases(94.4%) in the group of thymic hyperplasia(n=18) showed the improvement of symptoms. CONCLUSION: In myasthenia gravis, thymectomy showed the good improvement, and more important factor affecting the improvement of symptoms was the grdae of preoperative symptoms. Also midterm and long term follow up results showed good symptomatic improvement.
Acetylcholine
;
Autoimmune Diseases
;
Classification
;
Follow-Up Studies
;
Humans
;
Intubation
;
Medical Records
;
Mortality
;
Myasthenia Gravis*
;
Neuromuscular Junction
;
Outpatients
;
Pneumonia
;
Pneumothorax
;
Postoperative Complications
;
Respiratory Insufficiency
;
Survivors
;
Thymectomy
;
Ventilators, Mechanical
;
Vocal Cord Paralysis
7.Immediate changes in the mandibular dentition after maxillary molar distalization using headgear.
Sung Ja KANG ; Hyun Hee KIM ; Hyeon Shik HWANG ; Kyung Min LEE
The Korean Journal of Orthodontics 2017;47(2):142-147
The purpose of this study was to investigate immediate changes in the mandibular dentition after maxillary molar distalization using headgear in non-growing patients. Sixteen patients (mean age, 18.9 ± 2.0 years) with Class II molar relationship and crowding were included in the present study. To correct the molar relationship, headgear was used for maxillary molar distalization. Cone-beam computed tomography-generated half-cephalograms (CG Cephs) and dental casts were used to evaluate dental changes for each subject before and immediately after molar distalization using headgear. The mean duration that subjects wore the headgear was 6.3 months. CG Cephs showed that the first maxillary molars were distalized 4.2 ± 1.6 mm with 9.7°± 6.1° of distal angulation. The intercanine, interpremolar, and intermolar widths of the mandible increased after maxillary molar distalization. The present study's results suggest that maxillary molar distalization using headgear induces a spontaneous response in the untreated mandibular dentition of non-growing patients.
Dentition*
;
Humans
;
Malocclusion
;
Mandible
;
Molar*
8.Predictability of Impending Events for Death within 48 Hours in Terminal Cancer Patients.
In Cheol HWANG ; Chung Hyun CHOI ; Kyoung Kon KIM ; Kyoung Shik LEE ; Heuy Sun SUH ; Jae Yong SHIM
Korean Journal of Hospice and Palliative Care 2011;14(1):28-33
PURPOSE: Recognition of impending death is crucial not only for efficient communication with the caregiver of the patient, but also determination of the time to refer to a separate room. Current studies simply list the events 'that have already occurred' around 48 hours before the death. This study is to analyze the predictability of each event by comparing the time length from 'change' to death. METHODS: Subjects included 160 patients who passed away in a palliative care unit in Incheon. The analysis was limited to 80 patients who had medical records for the last week of their lives. We determined 9 symptoms and 8 signs, and established the standard of 'significant change' of each event before death. RESULTS: The most common symptom was increased sleeping (53.8%) and the most common sign was decreased blood pressure (BP) (87.5%). The mean time to death within 48 hours was 46.8% in the case of resting dyspnea, 13.6% in the ease of low oxygen saturation, and 36.9% in the case of decreased BP. The symptom(s) which had the highest positive predictive value (PV) for death within 48 hours was shown to be resting dyspnea (83%), whereas the combination of resting dyspnea and confusion/delirium (65%) had the highest negative PV. As for the most common signs before death within 48 hours, the positive PVs were more than 95%, and the negative PV was the highest when decreased BP and low oxygen saturation were combined. The difference in survival patterns between symptoms and signs was significant. CONCLUSION: The most reliable symptoms to predict the impending death are resting dyspnea and confusion/delirium, and decline of oxygen saturation and BP are the reliable signs to predict the event.
Blood Pressure
;
Caregivers
;
Dyspnea
;
Humans
;
Medical Records
;
Oxygen
;
Palliative Care
;
Prognosis
;
Terminally Ill
9.New Korean reference for birth weight by gestational age and sex: data from the Korean Statistical Information Service (2008-2012).
Jung Sub LIM ; Se Won LIM ; Ju Hyun AHN ; Bong Sub SONG ; Kye Shik SHIM ; Il Tae HWANG
Annals of Pediatric Endocrinology & Metabolism 2014;19(3):146-153
PURPOSE: To construct new Korean reference curves for birth weight by sex and gestational age using contemporary Korean birth weight data and to compare them with the Lubchenco and the 2010 United States (US) intrauterine growth curves. METHODS: Data of 2,336,727 newborns by the Korean Statistical Information Service (2008-2012) were used. Smoothed percentile curves were created by the Lambda Mu Sigma method using subsample of singleton. The new Korean reference curves were compared with the Lubchenco and the 2010 US intrauterine growth curves. RESULTS: Reference of the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles birth weight by gestational age were made using 2,249,804 (male, 1,159,070) singleton newborns with gestational age 23-43 weeks. Separate birth weight curves were constructed for male and female. The Korean reference curves are similar to the 2010 US intrauterine growth curves. However, the cutoff values for small for gestational age (<10th percentile) of the new Korean curves differed from those of the Lubchenco curves for each gestational age. The Lubchenco curves underestimated the percentage of infants who were born small for gestational age. CONCLUSION: The new Korean reference curves for birth weight show a different pattern from the Lubchenco curves, which were made from white neonates more than 60 years ago. Further research on short-term and long-term health outcomes of small for gestational age babies based on the new Korean reference data is needed.
Asian Continental Ancestry Group
;
Birth Weight*
;
Female
;
Gestational Age*
;
Growth Charts
;
Humans
;
Infant
;
Infant, Newborn
;
Information Services*
;
Male
;
United States
10.Extraskeletal Mesenchymal Chondrosarcoma of the Mediastinum: A Case Report.
Eun Gu HWANG ; Yong Woong YOON ; Dae Hyun KIM ; Bum Shik KIM ; Joo Chul PARK ; Dong Wook SUNG
The Korean Journal of Thoracic and Cardiovascular Surgery 2001;34(11):891-894
Mesenchymal chondrosarcoma arising in soft tissue of mediastinum is a very rare tumor. This paper reports an extraskeletal mesenchymal chondrosarcoma occuring in the posterior mediastinum.
Chondrosarcoma
;
Chondrosarcoma, Mesenchymal*
;
Mediastinum*