1.A study on the orthodontic tooth movement under half sine-wave pulsed electromagnetic fields.
Young Joon KIM ; Young Kyu RYU
Korean Journal of Orthodontics 1994;24(4):897-916
The biologic potential, which is different from the piezoelectric signals, relates tooth movement at least in part to changes in bone metaboliosm in bioelectric theory. The purpose of this experiment was to determine whether the application of half sine-wave pulsed electromagnetic fields (HSPEMF) could increase both the rate and amount of orthodontic tooth movement. Forty-three male Hartley guinea pigs, weighting approximately 255g, were utilized in this study. The animals were 35 days old at the start of the study. Laterally directed orthodontic force was applied to the maxillary central incisors of 40 Hartley guinea pigs (20 experimental, 20 control). According to the amount of orthodontic force (6g, 12g), they were divided into two sub-groups (10 experimental I, 10 experimental II, 10 control I, 10 control II). During the experimental period, experimental animals were placed in plastic animal holders with their heads positioned in an area of uniform electromagnetic field. Control animals were placed in similar plastic holders that did not carry the electric apparatus. The results were as follows: 1. The application of a HSPEMF to the experimental groups significantly increase the final amount of orthodontic tooth movement observed over a 10-day experimental period. 2. The application of a HSPEMF to the experimental groups significantly increase the velocity of orthodontic tooth movement observed over a 10-day experimental period. 3. There was no significant difference in the final amount of orthodontic tooth movement at the fourth day to the eighth day, but there was significant difference in the final amount of orthodontic tooth movement at the ninth, tenth day during a 10-day experimental period. 4. After 10 days of HSPEMF exposure & orthodontic force, the experimental groups demonstrated more osteoclasts in the pressure side than control groups.
Animals
;
Electromagnetic Fields*
;
Guinea Pigs
;
Head
;
Humans
;
Incisor
;
Magnets*
;
Male
;
Osteoclasts
;
Plastics
;
Tooth Movement*
;
Tooth*
2.Rationale and criteria for excellent finishing.
Young Kyu RYU ; Young Joon KIM
Korean Journal of Orthodontics 1999;29(6):637-648
Finishing is usually accomplished about four to seven months before the removal of orthodontic appliance in order to achieve ideal occlusion and excellent aesthetics. This process, called finishing, is the key to obtain excellent final results. Some of orthodontists believe it can be accomplished at the final stage of orthodontic treatment, and they complete it without their special rationale and criteria for finishing. However, it should be considered as a part of the total treatment plan from the beginning to end, and a guideline for finishing, which is based on rationale and criteria for the removal of orthodontic appliance, is needed to obtain the desired results. The guideline should include a checklist for finishing. This checklist is divided into four categories: occlusal, aesthetic, periodontal, and habitual factors. Occlusal factors include alignment, marginal ridge discrepancy, interproximal contact, anterior inclination, posterior inclination, over-jet, over-bite, arch form, and functional occlusion. Aesthetic factors include gingival form, crown form, crown width, and crown length. Periodontal factors include root angulation, bone level, and black hole in periodontal factors. Habitual factors consist of mouth breathing, tongue position at rest, tongue thrust, lip biting, nail biting, and finger sucking.
Checklist
;
Crowns
;
Esthetics
;
Fingersucking
;
Lip
;
Mouth Breathing
;
Nail Biting
;
Orthodontic Appliances
;
Tongue
3.Growth change in the lips of the adolescence (from 8 to 16 years old).
Young Hee KIM ; Joon ROW ; Young Kyu RYU
Korean Journal of Orthodontics 1996;26(2):141-151
This study was undertaken to assess the effect of growth on the lips. Not only does lip growth influence the stability of such orthodontic treatment: it also directly influence facial profile, in which the lips have an important part. An understanding of the growth of lips is thus central to a consideration of profile change in orthodontics. By analyzing the serial lateral cephalograms of 15 male and 15 female of 8 years old to 16 years old who have normal occlusion. The result of this study were summerized as follows; 1. The largest growth increments in the length of the lips was occured age of 14 in both sexes. 2. The thickness of lips showed lager value for the male than that of the female in the most age group. The largest growth increments at A point was occured age of 14, while Ls, Li, B point decreased after the age of 10-11. 3. The largest increase in the interval between crest of lower lip and edge of upper incisors was occured between ages 9 and 11 in males. The interval decreased slightly from 8 to 16 years in females. 4. The nasolabial angle decreased slightly from 8 to 16 years in both sexes. 5. The mentolabial angle showed large variation.
Adolescent*
;
Child
;
Female
;
Humans
;
Incisor
;
Lip*
;
Male
;
Orthodontics
4.The Clinical Study of the Lateral Collateral Ligament of the Ankle
Joon Young KIM ; Woo Shin CHO ; Young An CHOI ; Yang Seok RYU
The Journal of the Korean Orthopaedic Association 1988;23(2):358-363
The ankle is one of the most common site of ligamentous injury. The incidence of the injury is increasing in these days, probably due to prevailing leisure and sports. Lateral collateral ligament is more susceptible to injury than medial because of anatomical and biomechanical difference. There was a tendency to treat the ankle ligamentous injury with conservative method, but because of the problem of chronic and recurrent ankle instability and injury, operative method is necessary in certain patients. We have experienced of 14 cases of surgical treatment of the lateral ligaments, excluding the associated fracture, from March 1983 to February 1986, in Koryo General Hospital. Among 14 cases, the acute injury, which were treated with primary repair, were 9 cases and the chronic cases, which with modified Watson-Jones method, were 5. The average follow up period was 1 year and 2 months. The results are as follows : 1. The male and female ratio, was 9 to 5 and peak incidence was 3rd and 4th decade. 2. The cause of injury was mainly slip down (9 cases) and sports injury(4 cases). 3. There was no correlation between the degree of the ligament rupture and talar tilt. 4. When the talar tilt is above 10, it may cause ankle instability. 5. The clinical results are both satisfactory in acute and chronic cases, but in chronic cases, some degenerative changes began to appear in 2 cases. 6. C.P.M.(Continuous Passive Motion) and Air Cast have much advantages in postoperative care.
Ankle
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Clinical Study
;
Collateral Ligaments
;
Female
;
Follow-Up Studies
;
Hospitals, General
;
Humans
;
Incidence
;
Lateral Ligament, Ankle
;
Leisure Activities
;
Ligaments
;
Male
;
Methods
;
Postoperative Care
;
Rupture
;
Sports
5.The Clinical Study of the Supracondylar Fracture of the Femur
Joon Young KIM ; Young An CHOI ; Chang Goo SHIM ; Yang Seok RYU
The Journal of the Korean Orthopaedic Association 1990;25(2):353-358
The various methods of treatment of the supracondylar fractures of the femur were adapted by many authors according to degree of the involvement of the articular surface, displacement of fragments, degree of comminution and external forces. Authors experienced the supracondylar fracture of the femur in 31 cases who were treated at Koryo General Hospital from March 1984 until March 1988 and among them, 14 cases were treated by operative methods and 17 cases by conservative methods. The results were as follows:1. The male was more common, and the 3rd & 4th decades were most. 2. The most common cause of injuries was traffic accident. 3. The most common fracture type was type I by Neer's classification. 4. The type I was treated mostly by conservative methods and the type II & III by operative methods. 5. In the operative treatments, after anatomical reduction and rigid fixation, the duration of the rehabilitation was shortened by using the C.P.M. exerciser. 6. The complications were partial ankylosis of the knee, chronic osteomyelitis, nonunion and delayed union.
Accidents, Traffic
;
Ankylosis
;
Classification
;
Clinical Study
;
Femur
;
Hospitals, General
;
Humans
;
Knee
;
Male
;
Osteomyelitis
;
Rehabilitation
6.The Impact of Anxiety Symptoms on Cognitive Function in Patients with Mild Traumatic Brain Injury.
Seuk Hwan RYU ; Young Joon KWON
Korean Journal of Psychopharmacology 2015;26(1):17-21
OBJECTIVE: The aim of this study was to investigate the relationship between subjective anxiety symptoms and cognitive function in patients with mild traumatic brain injury. METHODS: A total 48 patients were recruited in this study. All participants were divided into two groups by anxiety symptoms in Hospital Depression and Anxiety Scale. Intelligence Scale and memory test were analyzed. RESULTS: A high risk group showed lower scores in all of verbal intelligence quotient (IQ) and total IQ in Intelligence Scale and memory quotient in memory test. CONCLUSION: This study suggests that anxiety symptoms make worse in cognitive function in patients with mild traumatic brain injury.
Anxiety*
;
Brain Injuries*
;
Depression
;
Humans
;
Intelligence
;
Memory
7.Three dimentional force analysis of force system in continuous archwire by finite element method.
Korean Journal of Orthodontics 1996;26(1):17-32
It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The arch wire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows: 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.
Crowding
;
Orthodontic Appliances
;
Tooth Movement
8.Analysis of Mediatinal Lymph Nodes with Internal Low Density on Contrast Enhanced CT Scan.
Young Hoon RYU ; Kyu Ok CHOE ; Yong Kook HONG ; Sung Kyu KIM ; Joon CHANG ; Won Young LEE
Tuberculosis and Respiratory Diseases 1997;44(2):264-279
BACKGROUND: To analyze the morphologic characteristics of low density lymph node in etiologic differentiation of lymphadenopathy, emphasizing the different features between tuberculosis and lung cancer, on contrast enhanced CT scan,. METHOD: A total of 64 patients who showed low density lymph nodes on chest CT scan were analyzed. Primary causes were tuberculosis (n=28), lung cancer (n=27), malignant lymphoma (n=5) and metastasis from extrathoracic malignancies (n = 4). CT scan was performed with 10mm slice thickness and 7 characteristic features were evaluated: location,size, presence or absence of the nonnecrotic lymph node, calcification, perinodal fat obliteration, thickness and evenness of the enhancing rim. RESULTS: In patients with tuberculous lymphadenopathy, lymph nodes with uneven (68.0%) and thick (62.1%) enhancing rim were more common than lung cancer (p<0.05). Low density lymph nodes with less than 1cm in size were found only in tuberculous lymphadenopathy(n=10). In 48.2% of patients with lung cancer, more than 1 nonnecrotic enlarged lymph node were coexisted, whereas 21.4% in patients with tuberculous lymphadenopathy(p=0.06). However, the size, location and calcification were not statistically significant between tuberculous lymphadenopathy and lung cancer. CONCLUSION: Tuberculous lymphadenopathy is strongly suggested when enhancing rim of enlarged lymph nodes is uneven and thick, when the coexisting nonnecrotic lymph nodes are few in number and when central low density is encountered in normal sized lymph nodes.
Humans
;
Inflammation
;
Lung Neoplasms
;
Lymph Nodes*
;
Lymphatic Diseases
;
Lymphoma
;
Neoplasm Metastasis
;
Tomography, X-Ray Computed*
;
Tuberculosis
9.Analysis of Human Tissue Management Models for Medical Research: Preparation for Implementation of the 2012 Revision of the Bioethics and Safety Act of Korea.
Young Joon RYU ; Hankyeom KIM ; Sejin JANG ; Young Mo KOO
Journal of Korean Medical Science 2013;28(6):803-807
Efficient management of human tissue samples is a critical issue; the supply of samples is unable to satisfy the current demands for research. Lack of informed consent is also an ethical problem. One of the goals of the 2012 revision of Korea's Bioethics and Safety Act was to implement regulations that govern the management of human tissue samples. To remain competitive, medical institutions must prepare for these future changes. In this report, we review two tissue management models that are currently in use; model 1 is the most common system utilized by hospitals in Korea and model 2 is implemented by some of the larger institutions. We also propose three alternative models that offer advantages over the systems currently in use. Model 3 is a multi-bank model that protects the independence of physicians and pathologists. Model 4 utilizes a comprehensive single bioresource bank; although in this case, the pathologists gain control of the samples, which may make it difficult to implement. Model 5, which employs a bioresource utilization steering committee (BUSC), is viable to implement and still maintains the advantages of Model 4. To comply with the upcoming law, we suggest that physicians and pathologists in an institution should collaborate to choose one of the improved models of tissue management system that best fits for their situation.
*Bioethics
;
Biomedical Research/*legislation & jurisprudence
;
Humans
;
Models, Biological
;
Republic of Korea
10.Choreoathetosis after cardiopulmonary bypass with deep hypothermia.
Chul Hee CHOI ; Young Hoon RYU ; Young Ho SHON ; Joon Hee SUL ; Byung In LEE
Journal of the Korean Neurological Association 1997;15(3):695-700
A 9-year-old boy showed orofacial dyskinesia and psychic symptoms shortly after open heart surgery with deep hypothemia and cardiopulmonary bypass for congenital cyanotic heart disease. The choreothetosis progressed to be generalized and accompanied by mental deterioration. This involuntary movement partially responded only to repetitive administration of sedatives. After 3 month the patient expired with sudden development of ventricular tachycardia and cardiogenic shock.
Cardiopulmonary Bypass*
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Child
;
Dyskinesias
;
Heart Diseases
;
Humans
;
Hypnotics and Sedatives
;
Hypothermia*
;
Male
;
Movement Disorders
;
Shock, Cardiogenic
;
Tachycardia, Ventricular
;
Thoracic Surgery