• The korean journal of orthodontics
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• v.39 no.1
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• pp.36-42
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• 2009

Objective: The purposes of this study were to provide an epidemiologic data base related to the orthodontic treatment need and to know the changing trends about treatment modality of private orthodontic clinics. Methods: Distribution, trends and orthodontic treatment plan of malocclusion patients were investigated in 1,620 consecutive patients who had been visited and examined in 4 private orthodontic clinics located in Seoul from 2003-2006. Results: Percentage of male and female patients was 26.9% and 73.1% respectively Age distribution had shown that percentage of the patients above 13 years was 78.9%, and above 19 years was 59.0%. Average age of whole patients was 20.5 years. With regard to Angle classification, each percentage of Class I, Class II division 1, Class II division 2 and Class III malocclusion was 38.9%, 34.8%, 2.3% and 24.0%. The percentage of extraction cases(00.9%) outnumbered nonextraction cases(39.1%) and 46% of extraction cases were upper and lower 1st premolar extraction cases. Patients who had chose treatment with fixed appliance and orthognathic surgery was 10.2%. Conclusions: Because the high percentage of adult, Class II malocclusion and orthognathic surgery cases in patients of private orthodontic clinics were shown in this study, orthodontic education program and national health policy in Korea need reformation.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.216-226
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• 2020

Root resorption can be caused by several factors, including contact with the cortical bone. Here we report a case involving a 21-year-old female with Angle Class II, division 1 malocclusion who exhibited significant root resorption in the maxillary right central incisor after orthodontic treatment. The patient presented with significant left-sided deviation of the maxillary incisors due to lingual dislocation of the left lateral incisor and a Class II molar relationship. Cephalometric analysis demonstrated a Class I skeletal relationship (A point-nasion-B point, 2.5°) and proclined maxillary anterior teeth (upper incisor to sella-nasion plane angle, 113.4°). The primary treatment objectives were the achievement of stable occlusion with midline agreement between the maxillary and mandibular dentitions and appropriate maxillary anterior tooth axes and molar relationship. A panoramic radiograph obtained after active treatment showed significant root resorption in the maxillary right central incisor; therefore, we performed cone-beam computed tomography, which confirmed root resorption along the cortical bone around the incisive canal. The findings from this case, where different degrees of root resorption were observed despite comparable degrees of orthodontic movement in the bilateral maxillary central incisors, suggest that the incisive canal could be an inducing factor for root resorption. However, further investigation is necessary to confirm this assumption.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.255-265
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• 1996

The purpose of this study was to investigate if there were a significant difference between cephalometric measurements of mandibular position derived from a centric occlusion tracing compared to those of a converted centric relation tracing in the Class III malocclusion. The sample consisted of 25 Class III malocclusion and 25 normal occlusion persons who had no orthodontic treatment. The records included an lateral cephalometrics in centric occlusion, centric relation and centric occlusion bite registration and diagnostic casts mounted on the SAM II articulator in CR. The amount of CR-CO discrepancy of condyle was recorded using a MPI(Mandibular Position Indicator, MPI $200^{(R)}$, Great Lakes Orthodontics, USA). The conversion of the CO cephalogram to CR using the MPI readings was performed on the Conversion work sheet. Measures of mandibular position were chosen for the purpose of this study. The comparison of the difference between CO and CR cephalometric measurements in the normal occlusion and Class III malocclusion group were studied. The results were as follows: 1. In the features of CR-CO discrepancy of the condyle, the condyle was displaced posterior and inferior when the teeth were in centric occlusion. The horizontal component(${\Delta}X$) in Class HI malocclusion group was greater than the vertical component(${\Delta}Z$) and also greater than the horizontal component(${\Delta}X$) in normal occlusion group. There was no statistically significant correlation between MPI measurements and the groups of normal occlusion and Class III malocclusion group. 2. In the comparison of the cephalometric measurements in each group, Normal occlusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity and ODI. Class HI malocclusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity, ODI, SNB, APDI, L1-FP and it had more significance than the normal occlusion group. 3. The Value of cephalometric measurements was significantly different between CO and CR but there were no differences between the groups of normal occlusion and Class III malocclusion. The results of this study suggest that if the discrepancies are greater than the amount of normal displacement from clinically captured centric relation, centric relation should be considered as the starting point for proper diagnosis and treatment planning.

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.549-557
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• 1997

This study was designed to investigate the attrition pattern in Angle Class III malocclusion with facial asymmetry. The sample consisted of three groups, the 20 subjects of normal occlusion group(Group I), the 12 subjects of class III malocclusion without facial asymmetry group(Group II) and 17 subjects of Class III malocclusion with facial asymmetry group(Group III). Attrition areas from canine to second molar on both sides in upper and lower arch, totally twenty, was marked by pencil and mesured by computer system(INTERGRAPH CO. USA) 2 times and the average value was used for date processing. Attrition areas from canine to second molar on both sides in upper and lower arch, totally twenty, was marked by pencil and mesured by computer system(INTERGRAPH CO. USA) 2 times and the average value was used for date Processing. All attrition areas were measured 2 times and the average value was used for data processing The data were statistically analyzed by SAS program. The results of this study were as follows. 1. Total attrition area in Group I was larger than in Group II and III. 2. There was no significant difference in attrition area between right and left side in each group, but attrition area in Group III was larger than in Group I and II. 3. In Group I, Maxillary attrition area was larger than mandibular attrition area, but in Group ll and III, there was no significant difference in attrition area between maxilla and mandible. 4. In Group III, the attrition area of deviated side was target than undeviated side 5. There was no significant difference in attrition area between chewing side and non-chewing side in each group. 6. The total attrition area was unaffected by gender.

• The Journal of the Korean dental association
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• v.18 no.3 s.132
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• pp.197-200
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• 1980

This study was undertaken to investigate the form and position of the mandible of upper prognathism in relation to craniofacial complex. The subjects consist of 20 males and 39 females with Class II, Division 1 malocclusion and measurements were achieved on lateral cephalograms. The results were a follows. 1. Infradentale was situated anteriorly to orbital plane, but point B, pogonion and menton were situated posteriorly. 2. Development of chin point area of female was poor than that of male. 3. In case of facial angle was large, ramus angle tend to be small, but gonial angle had tendency to be large.

• The korean journal of orthodontics
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• v.13 no.2
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• pp.209-222
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• 1983

Three patients who had Angle's Class II Division 1 malocclusion were treated by Bioprogressive therapy. In spite of their occlusions, the 3 patients did not have any skeletal problems. Their skeletal patterns were within normal range. So headgear or functional appliance therapy were not considered. During the treatment procedure, the most noteworthy results of Bioprogressive therapy were the effect of the Utility arch to intrude 4 mandibular anterior teeth, the effect of the Cuspid retractor in cuspid retraction and the effect of the Double delta retraction arch in the retraction of 4 anterior teeth. The whole treatment results in these cases which were achieved by Bioprogressive therapy were very favorable and the efficiency of this therapy was very excellent.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.855-864
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• 1998

The purposes of this study were to evaluate the cephalometric characteristics of Korean female patients with Class II division 2 malocclusion and to compare Korean females with Caucasian females who had same type of malocclusion. All of the samples had Class II division 2 malocclusion with deep overbite (more than 4mm) and full permanent dentition. These samples were divided into two groups according to the races: Group 1(N=16; Korean females; average age=18Y 2M) and Group 2 (N:20; Caucasian females; average age=14Y 2M). The pretreatment lateral cephalograms were measured, analyzed and compared by using 38 variables and independent t-test. And the results were as follows: 1. Although there were no differences in Overbite, SN to mandibular plane angle, Palatomandibular plane angle, and FMA between Group 1 and 2, the other vertical relation variables of maxilla and mandible (SN to palatal plane angle, SN to occlusal plane angle, ODI) of Group 1 showed more clockwise rotation tendency of occlusal plane and less hypodivergency tendency than those of Group 2. 2. There were no differences in mandibular body length and ramus height between Group 1 and 2 except small upper genial angle of Group 1. There was less counterclockwise rotation tendency of mandible in Group 1. 3. There were no statistical significant differences in UAFH/LAFH and PFH/AFH between Group 1 and 2. 4. Although there were no differences of overjet and anteroposterior position of mandible between Group 1 and 2, the position of maxilla of Group 1 was more retropositioned than that of Group 2. 5. Except the more protrusion of lower incisor to A-Pog of Group 1, there were no differences of inclination and distance of upper and lower incisors to basal plane between Group 1 and 2. 6. The distance from upper- first molar to palatal plane showed no difference between Group 1 and 2. But the distance from lower first molar to mandibular plane of Group 1 was greater than that of Group 2. So it may be partially related to the clockwise rotation of occlusal plane and the less counterclockwise rotation tendency of mandible of Group 1. 7. Group 1 had more protrusive upper and lower lips than Group 2.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.861-869
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• 1994

The purpose of this study was to investigate the relationship of nose profile with respect to skeletodental pattern, by measured and analyzed statistically the lateral cephalograms of 95 females (13 to 30 years old). Tge results were summerized as follows ; 1. The antero-posterior factors of the nose - nasofrontal angle, nasofacial angle, and dorsal length / ala length ratio were different among the malocclusion groups 2. There were no significant correlation between the the vertical nose factors and the skeletal factors 3. The Class I groups had a straight nose profile , the Class II groups had a convex profile ; the Class III groups had a concave profile.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.45-54
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• 1997

The purpose of this study was to evaluate the indications of bionator in Class II division 1 malocclusion, The 48 subjects were classified into good result group(group1) and poor result group(group2) in reference to posttreatment molar relation, posttreatment overbite and overjet, posttreatment profile, and relapse. Pretreatment lateral cephalograms were calculated and evaluated by t-test stepwise discriminant analysis. The results were as follows ; 1. In jaw bone relationship, ANB, facial convexity angle, AB to facial plane angle were significantly different between two treatment groups. In denture pattern, L1 to facial plane, L1 to A-Pog, FMIA, and U1 to facial plane were significantly different and m soft tissue profile, protuberance of lower lip and upper lip were significantly different between tw o treatment groups. 2. The results in according to discriminant analysis stated that L1 to facial plane, ANB, FMIA and protuberance of lower lip help prediction of treatment result of bionator. 3. 3 major influential variables were obtained by stepwise discriminant analysis - L1 to facial plane, articular angle and ANB difference. And Fisher discriminant function was made by these three major variables.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.280-289
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• 2016

Objective: The aim of this study was to analyze tooth movement and arch width changes in maxillary dentition following nonextraction treatment with orthodontic mini-implant (OMI) anchorage in Class II division 1 malocclusions. Methods: Seventeen adult patients diagnosed with Angle's Class II division 1 malocclusion were treated by nonextraction with OMIs as anchorage for distalization of whole maxillary dentition. Three-dimensional virtual maxillary models were superimposed with the best-fit method at the pretreatment and post-treatment stages. Linear, angular, and arch width variables were measured using Rapidform 2006 software, and analyzed by the paired t -test. Results: All maxillary teeth showed statistically significant movement posteriorly (p < 0.05). There were no significant changes in the vertical position of the maxillary teeth, except that the second molars were extruded (0.86 mm, p < 0.01). The maxillary first and second molars were rotated distal-in ($4.5^{\circ}$, p < 0.001; $3.0^{\circ}$, p < 0.05, respectively). The intersecond molar width increased slightly (0.1 mm, p > 0.05) and the intercanine, interfirst premolar, intersecond premolar, and interfirst molar widths increased significantly (2.2 mm, p < 0.01; 2.2 mm, p < 0.05; 1.9 mm, p < 0.01; 2.0 mm, p < 0.01; respectively). Conclusions: Nonextraction treatment with OMI anchorage for Class II division 1 malocclusions could retract the whole maxillary dentition to achieve a Class I canine and molar relationship without a change in the vertical position of the teeth; however, the second molars were significantly extruded. Simultaneously, the maxillary arch was shown to be expanded with distal-in rotation of the molars.