• Journal of dental hygiene science
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• 제11권3호
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• pp.251-255
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• 2011

Objectives One aspect of undesirable outcomes in orthodontic treatment includes excessive resorption of dental roots with mechanotherapy. The purpose of this study was to examine the relationship between treatment duration, adult and adolescent, gender, extraction and non-extraction root resorption after orthodontic treatment. Methods The subjects consisted of 140 orthodontic patients(adult : 70, adolescent : 70) who treated by standard edgewise technique at the three orthodontic hospital and clinic in seoul. Pre-treatment and post-treatment periapical radiographs were examined. The amount of root resorption was assessed for six anterior teeth according to criteria modified from Lupi et al root resorption score. Results Treatment duration was 24.7 months in the adult group and 33.5 months in the adolescents group. Between adult and adolescents group were significantly difference of mean of root resorption score(p<0.05). Female group and extraction group usually had higher prevalence of root resorption, but were not significant differences between the each groups(p>0.05). Conclusions When viewing these results, a lot of root resorption in adult patients appears, especially the maxillary central incisor, lateral incisor root resorption during orthodontic treatment occurs, so be careful and do more research to be done is suggested.

• The korean journal of orthodontics
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• 제40권6호
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• pp.432-443
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• 2010

Objective: The purpose of this prospective study was to evaluate the dentofacial effects of conventional and modified facemask therapies with rapid maxillary expansion, in a group of Class III patients; and compared with an untreated control group. Methods: The conventional facemask group (Group 1) comprised of 24 patients, 13 girls and 11 boys (mean age, $9.2{\pm}1.4$ years); the modified facemask treatment group (Group 2) comprised of 24 patients, 12 girls and 12 boys (mean age, $9.3{\pm}1.6$ years); and the control group (Group 3) comprised of 21 subjects, 11 girls and 10 boys (mean age, $9.8{\pm}1.9$ years). Treatment and control changes within the groups and the differences between the groups were analyzed statistically. Intra-group comparisons were evaluated using the non-parametric Wilcoxon's test and intergroup changes were analyzed using the Kruskal-Wallis test. The statistical significance of intergroup differences was further assessed with the Mann-Whitney test for independent samples and applying Bonferroni's correction (p < 0.016). Results: In group 1, SNB changes were less than the control. There were increases in SNA, ANB, SN-MP, A to N perp and Upper lip to E plane. In group 2, SNB, U1-NA (mm) U1-NA (${\circ}$) and Pog to N perp (mm) changes were less than the control. There were increases in SNA, ANB, SN-MP, A to N perp and Upper lip to E plane. Conclusions: Modified facemask appliance can be used effectively in Class III patients with a retrognathic maxilla. Facemask therapies with expansion resulted in an anterior advancement and translation of maxilla without rotation; and the mandible moved downward and backward ward in both treatment groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제21권6호
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• pp.468-474
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• 2020

The aim of this study was to compare the effect of a horseback riding simulator, Slings and Kendall Exercise on a cranio-vertebral angle and the neck pain of the Forward Head Posture. This study included 30 young people with forward head posture. They were randomly divided into three groups. Each group performed the exercises for six weeks three times a week from September 2018 to November 2018. The variations of cranio-vertebral angle and neck pain were analyzed using paired t-tests and a one-way ANOVA test. The results of the study are as follows. Three groups showed significant variations of cranio-vertebral angle and neck pain (p < 0.05). But comparison of cranio-vertebral angle and neck pain between the groups showed no significant difference (p > 0.05). This study found that each exercise group for forward head posture was effective for inducing normal cervical alignment and neck pain relief. Therefore, various exercises can improve the forward head posture.

• The korean journal of orthodontics
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• 제27권5호
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• pp.761-770
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• 1997

71 Class I malocclusion samples were selected and they were divided into premolar-extraction and non-extraction groups. Vertical and horizontal cephalometric evaluations on dental and soft tissue measurements were done before and after treatment. Also, treatment results in adolescent patients and adult patients were compared. The following conclusions were obtained: 1. In comparison of extraction and non-extraction groups, all the dental and soft tissue measurements, with exception of SN-MP angle, upper lip to E-line, vertical movement of upper first molar, md horizontal movement of lower first molar, showed statistically significant differences. 2. In comparison of extraction and non-extraction groups of adolescent samples, there were statistically significant differences in upper and lower incisor inclinations, horizontal dental movements from vertical reference line, positional changes in upper and lower lips, and mesial movements of upper first molar. 3. In comparison of extraction and non-extraction groups of adult samples, there were statistically significant differences in upper and lower incisor inclinations, horizontal dental movements from vertical reference line, positional changes in upper and lower lips from I-line and vertical reference line, vertical height of upper first molar, and mesial movement of lower first molar. 4. There was no statistically significant difference in SN-MP angle between extraction and non-extraction groups of both adolescent and adult samples.

• The korean journal of orthodontics
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• 제30권5호
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• pp.579-589
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• 2000

The purpose of this study was to evaluate the position of tongue and hyoid bone in relation to vortical facial patterns in the adult and child. Lateral cephalograms taken in adults(63 cases, 11.7 years in average age) and children(69 cases, 22.6 years in average age) were traced and measured about position and posture of tongue and hyoid bone using the horizontal and vertical reference lines. The angle of mandibular plane to SN Plane was employed to classify the samples into groups of hypodivergent and hyperdivergent. The comparison of the tongue/hyoid bone measurements between hypodivergent group and hyperdivergent group in the adult and child were statistically executed with Student's f-test. The results were as follows, 1. The tongue height was lower in the hyperdivergent group than in hypodivergent group, and higher in children than in adults. 2. The vertical height of hyoid bone was higher in hypodivergent group than in hyperdivergent group and also higher in children than in adults. 3. The anteroposterior position was of no significant difference in relation to age or vortical facial pattern. 4. The inclination of hyoid bone in relation to cranial base was steeper in children than in adults.

• The korean journal of orthodontics
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• 제34권3호
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• pp.229-240
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• 2004

The purpose of this study was to evaluate the compensatory changes of occlusal plane angle in relation to skeletal factors. Lateral cephalograms of 61 adults with normal occlusion and 92 adults with skeletal malocclusions were traced and measured to analyze skeletal factors and occlusal plane angles. In terms of horizontal relationships, the normal occlusion group and malocclusion group were classified Into subgroups of skeletal Classes I, II, and III, while in terms of vertical relationships, each group was also classified into horizontal , average, and vertical subgroups. Some measurements were evaluated statistically by ANOVA and Post Hoc, and the others were reviewed by Paired t-tests. In this study, only the occlusal plane angle to AB plane did not show a significant difference between the normal occlusion group and malocclusion group. After treatment, the occlusal plane angle to the AB plane of the malocclusion group was approximated to that of normal occlusion group. The LOP to AB plane angle of the normal occlusion group was 91.7 in skeletal Class I, 88.8 in skeletal Class II, and 93.5 in skeletal Class III. This study was done to assess the treatment changes of the occlusal plane in the malocclusion group, and to draw a comparison with the normal occlusion group in order to present a reference to establish a new occlusal plane inclination.

• Journal of the Korean Arthroscopy Society
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• 제5권2호
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• pp.124-130
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• 2001

Purpose : To identify occult intra-articular pathologies in the acute ankle fracture using arthroscopy and to investigate the factors to predict its possibility of occult injuries that could be occurred. Materials and Methods : This prospective study included fifty patients who got operation for the ankle fractures. Ankle arthroscopy was performed to document the type and anatomical location of occult lesion. We investigated the correlation between incidence of occult injuries and specific fracture type. Results : Of fifty ankles, 37 ankles had occult lesion. Twenty five loose bodies including displaced fragments were found and various cartilage lesions were found in 31 ankles. Tibial avulsion fragment by anterior inferior tibiofibular ligament was occurred in 6 cases. There was no correlation between the incidence of occult lesion and various factors including age, sex, injury mechanism and fracture type(p>0.05). Conclusion : The ankle arthroscopy had an effective role for the detection and treatment of occult injuries and it was difficult to predict the occurrence or associated accurately in all of th ankle fractures.

• The Journal of the Korea Contents Association
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• 제20권6호
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• pp.9-25
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• 2020

As laser scan and photogrammetry are extensively applied to 3D modeling, the Retopology has become a critically important part in the 3D modeling process. However, abundant time would be wasted if the wrong method for retopology is employed. This paper aims to select the most suitable method and software for retopology for different types of models so as to increase the effectiveness of 3D modeling. In this paper, retopology is divided into three types according to the existed software for retopology in the market: manual, automatic and wrapping type, all of which are investigated by their characteristics of retopology and software in which they are applied individually. Then case production is employed on Static Mesh Skeletal Mesh and Hard Surface Modeling by the above mentioned three methods. The advantages and disadvantages of the software in which the above three methods can be applied are summed up, and the manual type produces good results, the automatic type is fast, and the wrapping type requires a pre-existing base mesh and the most suitable method for retopology for each type of 3D models is demonstrated. This paper provides reference for retopology and increases the effectiveness of 3D modeling.

• The korean journal of orthodontics
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• 제31권5호
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• pp.535-548
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• 2001

The purpose of this study was to evaluate changes in soft tissue chin thickness and to investigate correlations between hard and soft tissues measurements after orthodontic treatment conducted by premolars extraction and incisor retraction. The sample consisted of 35 female adults with Angle classification class I or class II division 1 malocclusion. Using lateral cephalometric radiographs taken before and after treatment, hard and soft tissue structures were measured and reproducible six landmark on soft chin tissue were used to locate the various points of soft tissue contour of the chin. The res에ts were as follows : 1. There were signigicant correlations between pretreatment B-B', Pm-Pm' and pretreatment vortical skeletal measurements such as $MP{\perp}HP,\;MP{\perp}PP$, ALFH and between a-a', b-b', Me-Me' and measurements of sym-physeal morphology such as SL, SW, PL. 2. There were significant decreases at B-B', Pm-Pm' and significant increases at a-a', b-b' between pre-and posttreatment mea surements. 3. There were significant correlations among soft tissues changes and hard tissue changes except for changes at B-B' and the range of correlation coefficient was about 0.3-0.4. 4. There were significant differences at ${\Delta}UI-VP,\;LI{\perp}, and B-B' measurements between subgroups divided by posttreatment Pog-Pog' changes. 5. There were significant differences at ${\Delta}overbite,\;NPog{\perp}HP,\;and\;Me-Me'$ measurements between subgroups divided by posttreatment Me-Me' changes.

• Journal of the korean academy of Pediatric Dentistry
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• 제36권1호
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• pp.46-52
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• 2009

The purpose of this study was to compare the skeletal maturation of cervical vertebrae according to vertical skeletal patterns in the adolescents. Lateral cephalograms of 198 subjects(10 years old), 216 subjects(12 years old), and 138 subjects(14 years old) were reviewed, and subjects were classified according to vertical skeletal patterns. The 30 subjects were selected with the greatest predominance of vertical growth, and the other 30 subjects, with the greatest predominance of horizontal growth; these subjects comprised the vertical and horizontal groups, respectively. For evaluating of skeletal maturation, the concavity of inferior border and verticohorizontal ratio of cervical vertebrae were observed and measured according to age. The measurements were analyzed statistically by SPSS computerized program. The results were as follows : In general, the concavity of the inferior border of the cervical vertebrae was greater in the horizontal group than the vertical group in all of the 10, 12, 14 year olds, but was not statistically significant. The vertico-horizontal ratio of the 3rd and 4th vertebra of the horizontal groups was a significantly larger than the vertical groups in 12 year olds but did not show any statistical significance in 10 and 14 year olds. There were a weak negative correlations between SUM, FMA and the vertico-horizontal ratio for each groups at 12 ages.