1.Experimental study on the effect of heat treatment on the orthodontic wires.
Myung Seok LEE ; Byung Wha SOHN
Korean Journal of Orthodontics 1992;22(3):591-601
No abstract available.
Hot Temperature*
;
Orthodontic Wires*
2.A roentgenocephalometric study on soft tissue profile changes in pre-post treatment of Angle's Class II division I malocclusion.
Korean Journal of Orthodontics 1983;13(2):193-198
No abstract available.
Malocclusion*
3.A roentgenocephalometric study on soft tissue profile changes in pre-post treatment of Angle's Class III malocculusion.
Korean Journal of Orthodontics 1983;13(2):177-183
No abstract available.
4.Radiologic Evaluation About Urinary Tract Infection In Children.
Soon Wha KIM ; Byung Rai CHO ; Don Hee AHN ; Keun Chan SOHN ; Chong Hyun YOON
Journal of the Korean Pediatric Society 1989;32(6):797-803
No abstract available.
Child*
;
Humans
;
Urinary Tract Infections*
;
Urinary Tract*
5.A semilogitudinal study on cranial base, maxilliary and mandibular growth of Korean children aging 7 to 17 years old.
Byung Wha SOHN ; Hyung Soon KIM
Korean Journal of Orthodontics 1999;29(1):23-35
lateral cephalograms of 251 males and 286 females were taken and pubertal growth pattern of cranial base, maxillary and mandible of 7 to 17 years old Korean Children was evaluated. 10 landmarks and 16 analytical measurements were evaluated. Analytical measurement and annual difference for each age group was calculated and tested for statistical significance. Analytical measurements were classified into three groups which wee cranial base. maxillary and mandibular measurements and also classified into make and female measurements. Following results were achieved. 1. The circumpuberal growth spurt was earlier in Korean females than in males. 2. Cranial base, maxilla and mandible showed cirumpuberal growth. The cranial base showed a relatively smaller amount of growth the facial complex. 3. Middle and posterior cranial base length showed a greater increased than anterior cranial base length and circumpuberal growth spurt was also more definite. 4. The forward and downward growth of maxilla results from maxillary growth itself and transposition of the maxilla due to circumsutural growth around the maxilla. Ar-ANS and Ar-Pr which represent maxillary position relative to the cranial base showed more growth than ANS-PNS which represents maxillary bone growth. 5. mandible showed more vertical growth than horizontal growth but without significance. 6. Alveolar growth of maxilla and mandible show maximum growth rate of the time of permanent teeth eruption following loss of deciduous teeth. After this period alveolar growth shows a decreasing tendency.
Adolescent*
;
Aging*
;
Child*
;
Female
;
Humans
;
Male
;
Mandible
;
Maxilla
;
Skull Base*
;
Tooth
;
Tooth, Deciduous
6.An analysis of stress distribution in the case of unilateral molar expansion with precision lingual arch by finite element method.
Korean Journal of Orthodontics 1994;24(3):721-733
Orthodontic tooth movement is closely related to the stress on the periodontal tissue. In this research the finite element method was used to observe the stress distribution and to find the best condition for effective tooth movement in the case of unilateral molar expansion. The author constructed the model of lower dental arch of average Korean adult and used .032" x .032" x 60mm TMA wire. The wire was deflected in the horizontal and vertical direction to give the 16 conditions. The following results were obtained; 1. When the moment and force were controlled properly the movement of anchor tooth was minimized and the movement of moving tooth was maximized. 2. As the initial horizontal deflection increased the buccal displacement of both teeth was also increased. As the initial vertical deflection increased the lingual movement of anchor tooth and the buccal movement of moving tooth increased. 3. When the initial horizontal and vertical deflection rate was 1.5 the effective movement of moving tooth was observed with minimal displacement of anchor tooth.
Adult
;
Dental Arch
;
Humans
;
Molar*
;
Tooth
;
Tooth Movement
7.A study on the postoperative stability of occlusal plane in Class III orthognathic surgery patients.
Yoon Jeong LEE ; Byung Wha SOHN
Korean Journal of Orthodontics 2000;30(5):643-655
In Patients with severe skeletal discrepancy, surgical orthodontic treatment must be accompanied, and recently two jaw surgery has become a common procedure, resulting in improved esthetics and function. Choosing the position of the occlusal plane in this two jaw surgery is an important factor in postoperative stability. Therefore this must be taken into consideration during the diagnosis and treatment plan. In this study, among patients with skeletal Class III occlusion, 25 patients(8 male, 17 female, average age 23.2+/-3.17) who have undergone two jaw surgery, setting the ideal occlusal plane according to Delaire's architectural and structural cranial analysis. In comparing preoperative(T1). postoperative(T2, average of 15.4 days), and long-term postoperative(T3, average of 32.6 months) lateral cephalometric radiography, the following conclusions have been made. 1. There were no significant changes of the occlusal plane angle after the two jaw surgery, and there were no significant differences between the surgical technique(SSRO and IVRO). 2. The postoperative changes of the occlusal plane had no relationship with the amount of jaw movement, amount of posterior impaction, nor the time relapse after surgery. 3. After two jaw surgery, in the SSRO group there was significant forward movement of the mandible, and in the IVRO group the lower incisors extruded as the mandible moved backward and downward which makes the gonial angle and the mandibular plane angle significantly increased.
Dental Occlusion*
;
Diagnosis
;
Esthetics
;
Female
;
Humans
;
Incisor
;
Jaw
;
Male
;
Mandible
;
Orthognathic Surgery*
;
Radiography
;
Recurrence
8.Growth and develoment of arch form.
Byung Wha SOHN ; Hyoung Seon BAIK
Korean Journal of Orthodontics 1998;28(1):17-27
Study on growth change of dental arch is considered to both an important data in orthodontic diagonsis and treatment planning as well as analysis of treatment results ; also, arch form is important in anthropology and dentistry, even more so in prosthodontics and orthodontics. In the field of orthodontics, studies on the functional aspect of upper and lower teeth and maintenance of stability of dentition and occlusion were carried out from the early days. Some of the early studies include explanation of growth change in dental arch from measuring directly four human skull, and afterwards, cephalometcics x-rays were introduced; accordingly, studies using cephalometr c measurement and linear measurements of study models were often performed. By this method, arch width, arch depth and perimeters were measured, and growth change of dental arch was studied. The subject for this study were 600 children( boys and girls) of ages from 3 years to 12 years from Kang-won district and Seoul, who has no history of orthodontic treatment and who show healthy status and normal growth and development. Cephalometric x-ray, panoramic x-ray, and study model were taken for each subject consecutively for 2 years, and the subjects are still followed up. 400 pairs of study models from the past two years were used in this study,: mesio-distal diameater of each tooth, intercanine width, intermolar width, canine depth, molar depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and representation graph were drawn. The following conclusion were obtained. 1. Intercanine width showed gradual increase until the age of 10-years and after that, showed no increase. 2. Intermolar width in upper arch showed gradual increase = intermolar width in lower arch showed no significant chang, and after the age of 9-years, showed increase. 3. Gainine arch depth showed relatively rapid increase after the age of 6-years, and this pattern was more obvious in lower arch. 4. Molar arch depth increased gradually in both archs and it decrease after the age of 10-years : this phenomenon was more prominent in the lower arch. 5. Arch perimeter showed gradual inerease and convert to plateau at the age of 10-years, after that it decreased. this pattern was more prominent in lower arch.
Anthropology
;
Dental Arch
;
Dentistry
;
Dentition
;
Gangwon-do
;
Growth and Development
;
Humans
;
Molar
;
Orthodontics
;
Prosthodontics
;
Seoul
;
Skull
;
Tooth
9.The effects of changes of mandibular position on temporomandibular joint in adult rabbits whose retrodiscal tissues were incised.
Hyeon Shik HWANG ; Byung Wha SOHN
Korean Journal of Orthodontics 1992;22(2):345-372
The purpose of this experiment was to study the effects of changes of mandibular position on temporomandibular joint in internal derangement patients. Twenty-four female New Zealand White Rabbits, weighing over 3.5kg, were utilized in this study. Bilateral temporomandibular joint surgery was performed in twenty one of the rabbits to displace disc anteriorly through incising the retrodiscal tissue 1-2mm posterior to the disc, thus inducing internal derangement. They were divided into three groups: nine were left untreated after surgery, six were fitted with functional protrusive appliances 4 weeks after surgery, and six wore collar appliances to apply 4 ounces of mandibular retractive force per side 4 weeks after surgery. The remaining three served as the control group. Histologic examinations were performed after sacrificing them by threes at 4-week intervals. The results were as follows: 1. Histologic findings similar to internal derangement were observed in the rabbits whose retrodiscal tissues had been incised. 2. In the rabbits untreated after surgery, articular surface on condylar process and articular eminence showed severe erosion and deformation, and displaced disc manifested changes in both shape and internal architecture. 3. Functional protrusion after surgery resulted in progressive remodeling on posterosuperior portion of condyle and glenoid fossa, while it also brought about erosion on articular eminence and anterior portion of condyle. 4. Mandibular retraction after surgery resulted in compression of retrodiscal tissue and regressive remodeling of posterior portion of condyle.
Adult*
;
Female
;
Humans
;
Rabbits*
;
Temporomandibular Joint*
10.A study on the morphologic differences between long-face adults and normal-face adults on the lateral and P-A cephalograms.
Korean Journal of Orthodontics 1990;20(2):293-304
The purpose of this study was to describe the morphologic differences between long-face adults and normal-face adults on the lateral and P-A cephalograms. Long-face and normal-face subifects were selected clinically, and then each of them was taken the lateral cephalogram. According to SN-MP angle and ATFH on the lateral cephalogram, long-face group and normal-face group were classified. 2 long-face adults and 18 normal-face adults were collected, and each of them was taken the P-A cephalogram. The results were as follows: 1. The morphologic differences between long-face adults and normal-face adults were closely related to mandibular morphology. 2. Long-face adults, compared with normal-face adults, demonstrated significant increase in ALFH, and significant decrease in ramus height. 3. Long-face adults, compared with normal-face adults, demonstrated significant increase in AUDH and, ALDH, especially in ALDH. 4. On the P-A cephalogram, no measures of transverse dimension demonstrated significant differences between two groups. 5. On the P-A cephalogram, facial height/facial width ratio was significantly larger than normal in the long-face adults, and in the normal-face adults, facial height/facial width ratio was approximately 90%. 6. In the correlation analysis of SN-MP angle and ATFH with all the other variables, the correlation coefficients of SN-MP angle and PTFH/ATFH that of ATFH and ALFH on the lateral cephalogram demonstrated the highest value, and on the P-A cephalogram, SN-MP angle and Cg-GA-Me (Lt.), ATFH and lower facial height demonstrated the highest value of correlation coefficients.
Adult*
;
Humans