• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.41-49
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• 2003

This study examined the relations between degree of posterior dental compensation and skeletal discrepancy in Class III malocclusion. The pretreatment lateral cephalogras and dental casts of 87 skeletal Class III adults were selected to provide a random sampling of skeletal Class III malocclusion. Skeletal discrepancy was described with ANB angle, Wits appraisal, SN-Mn plane angle, FMA and ratios of basal arch width. Degree of posterior dental compensation was described with maxillary intermolar angle, mandibular interolar angle and sum of intermoloar angle. The relationships between skeletal discrepancy and degree of posterior dental compensation were analyzed with simple correlation analysis, stepwise multiple regression analysis. The results were as follows 1. A strong association was found between the variation in the anteroposterior measure, ANB angle and the variation of posterior dental compensation measures, sum of intermolar angle and mandibular intermolar angle in skeletal Class III malocclusion. 2. There was no statistically significant relationship between the variation in the vertical measures and the variation of posterior dental compensation measures in skeletal Class III malocclusion. 3. There was no statistically significant relationship between the variation in the anteroposterior and vortical measures and degree of basal arch width discrepancy.

• The Journal of the Korean bone and joint tumor society
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• v.4 no.1
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• pp.22-29
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• 1998

A limb-sparing operation has a definitive role in the treatment of osteosarcoma in the lower extremity of skeletally-immature patients. After a limb-sparing operation, leg length discrepancy remains as a major disability that should be corrected. This study was designed to suggest methods of tumor resection and proper timing of leg length equalization in skeletally immature osteosarcoma patients. From September 1990 to January 1998, we reviewed eight osteosarcoma patients in an immature skeletal age. There were 4 males and 4 females, and their mean duration of follow-up was 50.37 months (range : 25 to 88 months). Mean skeletal age was 8 years (range : 8 months to 11 years). The patients were classified according to the methods of tumor resection ; intercalary resection in 1 case, transepiphyseal resection in 1, intra-articular resection in 5, and extra-articular resection in 1. The results were as follows ; 1. The leg lengthening was begun when a patient's leg length discrepancy reached 4-5cm. 2. The age of final lengthening with permanent reconstruction was 14 years in males and 12 years in females (about 2 years before skeletal maturity). 3. When reconstruction was performed with a temporary spacer, the site of lengthening Was in the soft tissue, not in bone, and then a permanant reconstruction was done. 4. Reconstruction with a biologic spacer to preserve the joint function was a reasonable method for equalization of leg length. In conclusion, the appropriate choice of reconstructive method and the age at which to correct the leg length discrepancy in a skeletally-immature osteosarcoma patients are important factors for maintaining leg length at full maturity.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.87-98
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• 2023

This report presents a case of successful treatment of skeletal Class III malocclusion with transverse discrepancy in adult by surgery-first approach. Traditionally dental decompensation is necessary prior to surgery in 2-jaw surgery to correct transverse and rotational discrepancy. However, the hyrax-type palatal expansion appliance was used to improve maxillary expansion accuracy and postoperative stability in this surgery-first approach (segmental Le Fort I osteotomy and mandibular setback surgery). It was established to be an effective means of precisely predicting postoperative occlusion and achieving stable retention after surgery of skeletal Class III malocclusion with maxillary transverse discrepancy.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.380-393
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• 2004

The Purpose of this study was to investigate the dentoalveolar compensation according to anteroposterior skeletal discrepancy in normal occlusion and to evaluate cephalometric parameters that quantitatively describe dental compensations. The study consisted of 90 subjects (50 males. 40 females) who were selected among specimens of normal occlusion at Seoul National, University Dental Hospital, Dept. of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized for each subject. According to the anteroposterior skeletal pattern the sample was divided into three groups. Cephalometric data were analyzed for the three groups using the SPSS program. Independent t-test, correlation analysis and regression analysis were carried out. The results were as fellows: Dentoalveolar compensation was found in upper and lower incisor inclination and occlusal plane inclination. As the mandible located anterior to the maxilla, the maxillary incisors incisors more labially. the mandibular incisors more lingually, and the occlusal plane continued to flatten. The dental parameters most correlated with anteroposterior skeletal discrepancy were L1 to SN and L1 to FH. Among the compensatory dentoalveolar changes, lower incisor inclination was strongly related to the anteroposterior jaw relationship and played au imposrtant role in obtaining a normal incisor relationship U1 to PtGn and L1 to APog were constant irrelevant to anteroposterior skeletal discrepancy.

• The korean journal of orthodontics
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• v.53 no.2
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• pp.67-76
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• 2023

Objective: Morphometric and morphological evaluation of the mandibular condyle in adults and to identify its correlation with skeletal malocclusion patterns. Methods: Cone-beam computed tomography scans of 135 adult patients were used in this study and classified into groups according to four criteria: (1) sex (male and female); (2) sagittal skeletal discrepancy (Class I, Class II, and Class III); (3) vertical skeletal discrepancy (hyperdivergent, normodivergent, and hypodivergent); and age (group 1 ≤ 20 years, 21 ≤ group 2 < 30, and group 3 ≥ 30 years). The morphometrical variables were mandibular condyle height and width, and the morphological variable was the mandibular condyle shape in coronal and sagittal sections. Three-dimensional standard tessellation language files were created using itk-snap (open-source software), and measurements were performed using Meshmixer (open-source software). Results: The mandibular condyle height was significantly greater (p < 0.05) in patients with class III malocclusion than in those with class I or II malocclusion; the mandibular condyle width was not significantly different among different sexes, age groups, and sagittal and vertical malocclusions. There were no statistical associations between various mandibular condyle shapes and the sexes, age groups, and skeletal malocclusions. Conclusions: The condylar height was greatest in patients with class III malocclusion. The condylar height and width were greater among males than in females. The mandibular condyle shapes observed in sagittal and coronal sections did not affect the skeletal malocclusion patterns.

• The korean journal of orthodontics
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• v.52 no.5
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• pp.362-371
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• 2022

Orthognathic surgery is the primary treatment option for severe skeletal discrepancy. However, orthodontic camouflage should be considered as an alternative treatment option, considering the risks of surgery. A 19.5-yearold man presented with a severe prognathic mandible with a Class III molar relationship and an anterior crossbite. Orthognathic surgery could be considered because of his severe skeletal discrepancy and mandibular prognathism. However, the anesthetist for orthognathic surgery did not recommend surgery under general anesthesia because of risk factors associated with the patient's aplastic anemia, including bleeding and infections. Thus, a camouflage treatment to promote backward rotation of the mandible via orthodontic extrusion of the posterior teeth was planned. An anterior bite plate, intermaxillary elastics, and fixed orthodontic appliances were used to extrude the posterior teeth and to align the dentition. After 17 months of nonsurgical orthodontic treatment, normal occlusion was achieved, and the facial profile was dramatically improved. This case report describes the dentoskeletal and soft-tissue effects of mandibular rotation and its long-term stability.

• The Journal of the Korean dental association
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• v.57 no.6
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• pp.344-351
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• 2019

Skeletal Class III malocclusion is a relatively common form of malocclusion in Korea. In borderline cases where only mild skeletal discrepancy exists and if worsening of the facial profile is expected as a result of premolar extraction, mandibular full arch distalization with miniscrews is the treatment of choice. The purpose of this study was to investigate the pattern of tooth movement and evaluate the stability of mandibular full arch distalization and to identify correlation between stability and factors such as initial skeletal pattern, dental changes during treatment and alveolar bone in symphysis region using lateral cephalograms.

• The korean journal of orthodontics
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• v.50 no.5
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• pp.304-313
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• 2020

Objective: The aim of this study was to evaluate the stability of bimaxillary surgery involving bilateral intraoral vertical ramus osteotomy performed with or without presurgical miniscrew-assisted rapid palatal expansion (MARPE) in adult patients with skeletal Class III malocclusion. Methods: A total of 40 adult patients with skeletal Class III malocclusion were retrospectively divided into two groups (n = 20 each) according to the use of MARPE for the correction of transverse maxillomandibular discrepancy during presurgical orthodontic treatment. Serial lateral cephalograms and dental casts were analyzed until 6 months after surgery. Results: Before presurgical orthodontic treatment, there was no significant differences in terms of sex and age between groups. However, the difference of approximately 3.1 mm in the maxillomandibular intermolar width was statistically significant (p < 0.001). Two days after surgery, the mandible had moved backward and upward without any significant intergroup difference. Six months after surgery, the maxillary intercanine (2.7 ± 2.1 mm), interpremolar (3.6 ± 2.4 mm), and intermolar (2.0 ± 1.3 mm) arch widths were significantly increased (p < 0.001) relative to the values before presurgical orthodontic treatment in the MARPE group; these widths were maintained or decreased in the control group. However, there was no significant difference in surgical changes and the postsurgical stability between the two groups. No significant correlations existed between the amount of maxillary expansion and postsurgical mandibular movement. Conclusions: MARPE is useful for stable and nonsurgical expansion of the maxilla in adult patients with skeletal Class III malocclusion who are scheduled for bimaxillary surgery.

• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.313-324
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• 2004

The Purpose of this study was to investigate the predictors of relapse in orthodontic treatment of skeletal Class III malocclusion in growing patients. A total of 55 patients were studied and all subjects were divided into two groups according to their stability in the post-treatment stage. Of the sample, 33 patients were included in the stable group and the remaining 22 were assigned to the relapse group. Cephalometric data of the pre-treatment stage was taken and compared between the stable and relapse group. The following results were obtained through t-test: 1. This study presented statistical evidence to show that the major skeletal determinant of prognosis in Class III orthodontic treatment was not anteroposterior discrepancy .but vertical discrepancy, especially within the AB-maxillo mandibular triangle. Vertical angular measurements that showed statistically significant differences were AB-MP and ODI(P<0.01) and the vortical ratio measurements were MP-P/AL and PP-P/AL(P<0.05). 2. Relapse tendency increased with the steep occlusal Plane, especially the steep lower occlusal plane. As to occlusal plane, there were statistically significant differences in OP(L)-PP, OP-PP, AB-OP(L) and Wits appraisal(P<0.05). This study claimed that anteroposterior discrepancy was not necessarily the proper criteria to predict relapse. Vertical discrepancy had a significant effect on post-treatment stability.

• The korean journal of orthodontics
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• v.52 no.5
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• pp.372-382
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• 2022

Anterior open bite and transverse discrepancy are often accompanied by hyperdivergent skeletal patterns. In addition, degenerative joint disorders and vertical maxillary excess contribute to an unfavorable convex facial profile with a retruded chin. Correction of this complex three-dimensional problem with orthodontic treatment alone is considered challenging owing to anatomical limitations. Moreover, a history of orthodontic treatment with premolar extraction makes retreatment difficult. This case report illustrates the application of a maxillary tissue bone-borne expander and biocreative reverse curve system in a 23-year-old female patient with a severe anterior open bite and transverse discrepancy who underwent orthodontic treatment with four premolar extractions. By setting the treatment target under precise diagnosis and using appropriate appliances, a satisfactory treatment result could be achieved without orthognathic surgery.