• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.881-889
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• 1997

The purpose of this study was to compare four groups of Oriental young adults (169 males and 174 females) with normal occlusion and well balanced faced. Lateral cephalograms of 100 Koreans, 100 Chinese, 72 Vietnamese and 71 Japanese were digitized and six profile measures were computed. Analyses of variance showed that total facial profile(Gl'-Pr'-Pg') of Chinese was significantly less convex than the profile of Koreans or Vietnamese. Facial profile(Gl'-Pr'-Pg') of Chinese was also significantly less convex than that of Vietnamese. Holdaway's soft tissue angle(Pg'-LS:N-B) was significantly greater in Vietnamese than Chinese and Koreans, who were in turn greater than Japanese. The upper lip of Vietnamese is significantly closer to Ricketts' esthetic plane, than Chinese; Koreans and Japanese are significantly further behind the plane than Chinese. The lower lip of Koreans and Japanese was close to the esthetic plane, while Chinese and Vietnamese were approximately 2mm ahead. The nasolabial angle was significantly smaller for Chinese and Japanese than Koreans and Vietnamese. Sex differences were primarily dependent on the nose; total facial convexity and the nasolabial angle wert significantly larger in females than males. The results of this study demonstrate that a single standard of facial Profile is not sufficient or appropriate for Oriental patients.

• The korean journal of orthodontics
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• v.36 no.5
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• pp.369-379
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• 2006

Objective: The purpose of this study was to find changes in the occlusal plane related to different vertical facial patterns and suggest treatment goals and conduct possible treatment mechanisms. Methods: 60 adult patients (28 males, 32 females) who had been diagnosed as Class 1 skeletal malocclusion and treated without extraction were selected. Patients were divided into three groups; short face type (group 1), average face type (group 2) and long face type (group 3), using the data on normal occlusion of Korean adults. Results: The results were achieved by analyzing cephalometric tracings of each group at pre-treatment, end-treatment and post-treatment (about 1 year recall check). The inclination of the occlusion plane tends to gradually increase as the face becomes longer In group 1, COP-X, FOP-X, L6/L1, MP-L6 were significantly decreased, and L1-FOP was significantly increased during the retention period (T3-T2). Group 2 showed no significant change, In group 3, FOP-X was significantly increased during the retention period (T3-T2). During the retention period, FOP-X showed significant change among each group, especially between group 1 and group 3. Conclusion: These results suggest that changes of occlusal plane inclination according to facial vertical pattern need to be considered during the retention period for intrusion, extrusion, and incisor overbite.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.579-587
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• 2001

Cleft palate has been studied with epidemiologic and molecular methods, and many etiologic factors have been examined closely Among the research methods, biologic molecule research has been the most important method for cleft palate formation study The $TGF-\beta$ played an important role in cell migration, epithelial-mesenchymal transdifferentiation, extracellular matrix synthesis and deposition. But there was not much research on the correlation cleft palate induced by beta-aminonitroproprionitrile(BAPN) and $TGF-\beta$ expression. The purpose of the present study was to examine how $TGF-\beta$ is expressed in cleft palate rats. 4 Timed-pregnant Sprague-Dawley rats were obtained on the 10th gestation day. On the 13th day of gestation, BAPN-monofumarate salts (${(C_3H_6N_2)}_2{\cdot}C_4H_4O_4$) were individually, ovally administered to 3 pregnant rats at a ratio of 1g/kg body weight. And 4 pregnant rats were sacrificed on day 20 post coitus (p.c.). The $TGF-\beta$ expression in the cleft formed rats fetuses showed the following patterns : 1. Osteoblast and mesenchymal cells of the cleft pa)ate rats were of low expression compared with those of the control rats. 2. The cleft palate rats didn't show uy difference in the $TGF-\beta$ expression of osteocyte item the control rats. 3. In western blot analysis, the thickness of band of $TGF-\beta$ in the cleft palate rats was thinner and more diluted than that of the control rats.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.211-218
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• 2011

Purpose: Intentional replantation (IR) is a suitable treatment option when nonsurgical retreatment and periradicular surgery are unfeasible. For successful IR, fracture-free safe extraction is crucial step. Recently, a new extraction method of atraumatic safe extraction (ASE) for IR has been introduced. Patients and Methods: Ninety-six patients with the following conditions who underwent IR at the Department of Conservative Dentistry, Seoul National University Bundang Hospital, in 2010 were enrolled in this study: failed nonsurgical retreatment and periradicular surgery not recommended because of anatomical limitations or when rejected by the patient. Preoperative orthodontic extrusive force was applied for 2-3 weeks to increase mobility and periodontal ligament volume. A Physics Forceps was used for extraction and the success rate of ASE was assessed. Results: Ninety-six premolars and molars were treated by IR. The complete success rate (no crown and root fracture) was 93% (n = 89); the limited success rates because of partial root tip fracture and partial osteotomy were 2% (n = 2) and 5% (n = 5), respectively. The clinical and overall success rates of ASE were 95% and 100%, respectively; no failure was observed. Conclusions: ASE can be regarded as a reproducible, predictable method of extraction for IR.

• The korean journal of orthodontics
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• v.40 no.4
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• pp.212-226
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• 2010

Objective: The aim of this study was to evaluate the effect of remineralization and inhibition to demineralization after fluoride gel (acidulated phosphate fluoride, APF) or hydroxyapatite (HAp) paste application on interdentally stripped teeth. Methods: After interdental stripping, 1.23% APF or 5%, 10% HAp paste were applied for 7 days for remineralization. Afterwards, teeth were exposed to lactate carbopol buffer solution for demineralization. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to compare change in surface contents and crystal structures after remineralization, and then after demineralization. Results: EDS analysis indicated that calcium (p < 0.001) and phosphate (p < 0.01) contents were increased after 10% HAp paste application on stripped enamel, calcium (p < 0.05) and phosphate (p < 0.01) contents were increased after 5% HAp paste application, and fluoride (p < 0.01) contents were increased after 1.23% APF application. SEM image showed that enamel surfaces became smoother and crystal structures became small and compact after APF or HAp application. After demineralization, calcium (p < 0.05) and phosphate (p < 0.05) contents remained increased on the enamel remineralized with 10% HAp paste, and phosphate (p < 0.05) contents remained increased on the enamel remineralized with 5% HAp paste. After demineralization, surfaces looked less destroyed in the enamel remineralized beforehand than those of the control, and small pores between crystal structures, formed by remineralization were remained. Conclusions: Hydroxyapatite paste and fluoride gel were helpful to remineralize and inhibit deminerlization on stripped enamel.

• The korean journal of orthodontics
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• v.40 no.4
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• pp.250-259
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• 2010

Objective: Intraoral noncompliance upper molar distalization techniques have gained in popularity and have subsequently found to be successful in Class II correction. The aim of the present study was to introduce a screw supported intraoral distalization appliance and investigate its efficiency. Methods: Twenty-one subjects (11 females, 10 males; average age of 14.9 years) with Angle Class II malocclusion participated in this study. Two screws were inserted behind the incisive foramen and immediately loaded to distalize the upper first molars. An intraoral screw supported distalization appliance was used to distalize the upper molars in order to achieve a Class I molar relationship. Skeletal and dental changes were evaluated using cephalometric and three-dimensional (3D) model analysis. Results: Upper molars were distalized 3.95 mm on average and a Class I molar relationship was achieved without any anchorage loss. The upper molars were tipped only $1.49^{\circ}$ and the upper right and left molars were rotated only $0.54^{\circ}$ and $0.74^{\circ}$ respectively which were statistically non-significant (p > 0.05). Conclusions: The newly designed screw supported noncompliance distalization appliance was found to be an effective device for achieving bodily molar distalization without any anchorage loss.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.187-202
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• 1984

There are evidences that exogenous electric currents are capable of enhancing bone formation and resolution, and that the conversion of the bioelectric response to biochemical activity provides the directional component of orthodontic tooth movement. In addition, evidence has implicated cyclic nucleotides in alveolar bone cellular activation mechanism during orthodontic tooth movement. In view of these evidences, this study was performed to investigate the effects of exogenous electric currents on cyclic nuclotide levels in feline alveolar bone and the possible clinical application of electric currents as an additional orthodontic tool. In the first study, three groups of three adult cats were subjected to application of a constant direct current of $10{\pm}2$ microamperes to gingival tissue near maxillary canine noninvasively for 1, 3, and 7 days respectively. In the second study, three groups of three adult cats each were treated by an electric-orthodontic procedure for 1, 3, and 7 days respectively. The left maxillary (control) canine received an orthodontic force of 80gm alone at time of initiation, while the right maxillary (experimental) canine received combined force-electric stimulation (80gm of force and $10{\pm}2$ microamperes of a constant D.C. currents). Alveola, bone samples were obtain from the mesial (tension and/or cathode) and the distal (compression and/or anode) sites surrounding maxillary canines as well as from contralateral control sites. The samples were extracted, boiled, homogenized, and the supernatants were assayed for cyclic nucleotides (cAMP, cGMP) by a radioimmunoassay method. And also the amount of tooth movement was measured in the second study. On the basis of this study, the following conclusions can be drawn: 1. The fluctuation pattern of cyclic nucleotide levels in alveolar bone treated by exogenous electric currents was similar to that treated by orthodontic force. 2. The cAMP levels in alveolar bone of electrically treated teeth significantly elevated above the control values. And of electrically treated teeth, the values of the anode sites were higher than those of the cathode sites. 9. The cGMP levels in alveolar bone of electrically treated teeth elevated above the control values at the initiation phase of treatment, but dropped below the control values at time of termination. And of electrically treated teeth, the values of the cathode sites were higher than those of the anode sites. 4. The rate of tooth movement in teeth . treated by force-electric combination increased with the length of treatment as compared to that treated by mechanical force alone.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.85-100
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• 1981

Serial lateral cephalometric radiographs of 40 Korean children(25 males, 15 females) ranging in age from 6 to 13 years were studied by means of computer morphometrics and statistical analysis. As a result of this study, the following conclusions can be made: 1. In both sexes, the mean growth patterns of the face were very stable and the growth directions of the face were more prominent both forward and down-ward away from the cranial base(S-N). 2. In the mandible, the rotation and the 'wave-like' manner of migration were observed. 3. The size of the lateral faces in males was larger than females at 6 and 13 years of age, and the forms of the lateral faces in males were slightly more squares than females at 13 years of age. 4. The sex differences and practical means in the growth increments and growth rates during 7 years of the growth period were as follows: (1) In the total face, there was a significant sex difference in the growth increments(males $26.21cm^2$, females $23.24cm^2$) and growth rates(males $42.02\%$, females $39.28\%$). (2) In the facial surface 1, there was a significant sex difference in the growth increments(males $21.30cm^2$, females $19.19cm^2$) but there was no significant sex difference in the growth rates(males $41.35\%$, females $39.10\%$). (3) In the anterior total facial height(N-Ne), there was no significant sex difference in the growth increments(males 18.23mm, females 17.45mm) and the growth rates(males $18.44\%$, females $18.19\%$). (4) In the posterior total facial height(S-Go), there was a significant sex difference in the growth increments(males 14.61mm, females 12.98mm) but there was no significant sex difference in the growth rates(males $23.78\%$, females $22.25\%$). 5. The percentages of anterior upper facial height to anterior total facial height in both sexes were very stable in spite of the age increase. 6. The percentage of total facial height to standing height was reduced by the age increase, and the reduced rate of anterior total facial height(males $13.26\%$, females $13.75\%$) was larger than the posterior total facial height(males $9.95\%$, females $11.70\%$). 7. The correlations of lateral facial surfaces to the standing height and the weight were higher in males than females, but the level of correlation in males was in the moderate range.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.85-106
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• 1986

The purpose of this investigation was to know the means of the T.M.J. space and to compare spational differences in centric relation and centric occlusion by the T.M.J. Tomogram and to study the correlation between the articular eminence slope and the lingual surface slope of the maxillary central incisor by the Cephalogram in near normal occlusion subjects. These results could give contribution for the diagnosis of orthodontic treatment and T.M.J. dysfunction and the assessment of orthopedic treatment and orthognathic surgery. 44 young adults (28 men and 16 women, 21 to 27 years of age) were selected from the Dental students in Yonsei Univ. Criteria for selection was normal occlusion, no clinical signs and T.M.J. dysfunction, no history of orthodontic treatment, and no missing tooth. After submental vertex view analysis. each subject was given the T.M.J. Tomogram in centric relation and centric occlusion and the Cephalogram was given with Quint Sectograph. All data was recorded and statistically processed with the CYBER computer system. Results were analyzed: the following findings and conclusions were derived. 1. The mean value for the combined right and left anterior joint space was 2.549mm, the posterior space was 2.260mm, and superior space was 3.31mm in centric relation. The anterior space was 2.316mm, posterior space was 2.474mm, and superior space was 3.435mm in centric occlusion. 2. In the centric relation position, both condyles were placed more posterioly and superioly in their fossae than in the centric occlusion position by the spatial difference. 3. In the centric occlusion position, both condyles were more symmetrically placed in their fossae with equal anterior-posterioly rather than in the centric relation position. 4. The mean articular eminence angle was $48.19^{\circ}$ and the mean fossa height was 7.911mm. A strong positive correlation between the articular eminence angle and fossa height in T.M.J. Tomogram was found. 5. In Cephalometric analysis, there was a strong positive correlation between the articular eminence slope and the lingual surface slope of the upper central incisor to the FH plane, occlusal plane, and S-N plane. 6. There was moderate positive correlation between the S-E measurements and the fossa height, articular eminence angle, and DcGn < F-H.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.197-221
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• 1991

The purpose of the present study was to investigate the differences of EMG activity of the masticatory muscles between normal occlusion and Class III malocclusion during various jaw functions. 46 subjects of 18.4-25.7 years were employed in this study: 26 subjects were normal occlusions, and 20 subjects were Class III malocclusions. The EMG data from the anterior and posterior temporal, anterior and posterior masseter muscles in both sides as mandibular elevators and supra-hyoid muscle group (close to the anterior belly of digastric muscle in right side) as mandibular depressor were recorded with the Medelec MS 25 electromyographic machine. The EMG recordings were analyzed during mandibular rest position, maximal biting, mastication with chewing gum, and swallowing of peanuts. All data were recorded and statistically processed. 1. The maximal mean amplitude of the anterior temporal muscle was stronger significantly in Class III malocclusion than in normal occlusion, and then the posterior temporal was weaker during mandibular rest position. 2. The maximal mean amplitudes in the anterior and posterior temporal muscles and the anterior masseter muscle of Class III malocclusion was weaker significantly than that of normal occlusion during maximal biting. 3. During mastication of the chewing gum, the maximal mean amplitudes of Class III malocclusion was weaker significantly than normal occlusion in the anterior and posterior temporal muscles of the working side, and the duration of Class III malocclusion was longer in the anterior temporal muscles of both aides, and the posterior temporal and the anterior masseter muscle of the balancing side. There were significant increasings of the latency in balancing anterior temporal, working posterior temporal muscles and supra-hyoid muscle group of Class III malocclusion. The silent period durations was 16.36 ms in Class III malocclusion while 10.76 ms in normal occlusion, which was statistically different (P < 0.05). 4. At swallowing of peanuts, the maximal mean amplitude of Class malocclusion was weaker significantly in the posterior temporal muscle than that of normal occlusion. There was no significant difference of duration between normal occlusion and Class III malocclusion. 5 The muscle activities of Class III malocclusion had a tendency of decrease less than normal occlusion. And then the muscle activities of the anterior temporal and anterior masseter muscles in Class III malocclusion showed the tendency of the increase more than other muscles of Class III malocclusion.