• The Journal of the Korean dental association
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• v.15 no.2
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• pp.107-110
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• 1977

Class I malocclusion is essentially a dental dysplasia. Rotations, individual tooth malpositions, missing teeth, tooth size discrepancies, etc., fall under this classification. There are two types of class I malocclusions. One is identified by and insufficient denture base to accommodate the teeth; the other has more denture base than tooth material, creating spaces in the arch. The tooth material-to denture base discrepancies may be slight, calling for only a little increase in arch length for alignment and the correction of minor rotations. Discrepancies may also be great, in which case it becomes necessary to reduce tooth material by extraction, so as to make the tooth material more in proportion to the size of the denture base. The author had attempted orthodontic treatment of a class I malocclusion case of 13-year old boy in which high canines and impacted mandibular second premolars were involved. The author obtained good results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.907-915
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• 2000

The movement of teeth and initial stress associated with the treatment of orthodontics have been successfully studied using the finite element method. To reduce the effort in preprocessing of finite element analysis, we developed two types of three-dimensional finite element models based on the standard teeth model. Individual malocclusions were incorporated in the finite element The movement of teeth and initial stress associated with the treatment of orthodontics have been successfully studied using the finite element method. To reduce the effort in preprocessing of finite element analysis, we developed two types of three-dimensional finite element models based on the standard teeth model. Individual malocclusions were incorporated in the finite element models by considering the measuring factors such as angulation, crown inclination, rotation and translations. The finite element analysis for the wire activation with a T-loop arch wire was carried out. Mechanical behavior on the movement and the initial stress for the malocclusion finite element model was shown to agree with the objectives of the actual treatment. Finite element models and procedures of analysis developed in this study would be suitably utilized for the design of initial shape of the wire and determination of activation displacements.

• Journal of Periodontal and Implant Science
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• v.45 no.1
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• pp.8-13
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• 2015

Purpose: The aim of this study was to evaluate the transfer of different occlusal forces in various skeletal malocclusions using finite element analysis (FEA). Methods: Three representative human cone-beam computed tomography (CBCT) images of three skeletal malocclusions were obtained from the Department of Orthodontics, Yonsei University Dental Hospital, Seoul, South Korea. The CBCT scans were read into the visualization software after separating bones and muscles by uploading the CBCT images into Mimics (Materialise). Two separate three-dimensional (3D) files were exported to visualize the solid morphology of skeletal outlines without considering the inner structures. Individual dental impressions were taken and stone models were scanned with a 3D scanner. These images were integrated and occlusal motions were simulated. Displacement and Von Mises stress were measured at the nodes of the FEA models. The displacement and stress distribution were analyzed. FEA was performed to obtain the 3D deformation of the mandibles under loads of 100, 150, 200, and 225 kg. Results: The distortion in all three skeletal malocclusions was comparable. Greater forces resulted in observing more distortion in FEA. Conclusions: Further studies are warranted to fully evaluate the impact of skeletal malocclusion on masticatory performance using information on muscle attachment and 3D temporomandibular joint movements.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.121-130
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• 1984

Childrens between the ages of 13 and 15 years, living in Seoul, were examined in order to determine the prevalence and severity of malocclusion in the permanent dentition. This survey encompassed 981 children and an individual chart was prepared for each subject recording an original HMAR score and classification of occlusion according to Angle. Also, subjective evaluation of "treatment needs" was carried out in 581 children. The results were as follows: 1. Of the 981 children in this survey, 12,1 percent showed excellent occlusion. (0 point) 2. The 14 percent of the children who had a score of 24 and above all appeared to belong to the "treatment highly desirable" or "treatment mandatory" category. 3. The incorporation of SAR (Supplementary Assessment Record) into the HMAR can provide more sensitive method for evaluating severity of malocclusion. 4. According to Angle's classification 77.4 percent of all malocclusion belonged to Class I, 1.3 percent to Class II, Division 1, 0.9 percent to Class II, Division 2, and 11.3 percent to Class III. 5. The mean HMAR score for Class I was significantly lower than for either Class II, Division 1 or Class III. (P < 0.05) 6. A close relationship was found between the degree of "treatment needs" and the value obtained by the HMAR scoring. (chi-square test, p < 0.05) The differences between the mean HMAR scores of the various subjectively defined categories were statistically significant. (P < 0.001)

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.219-237
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• 1999

This study was designed to evaluate the frequency and the severity of root resorption of the permanent teeth before orthodontic treatment by means of radiograph in the malocclusion patients. In this study the author analysed the frequency and the severity of root resorption in individual teeth, the relationships of the frequency and the severity of root resorption and age, sex, Angle's classification, overjet, overbite, and maxillary and mandibular incisor inclination, and the relationships of the frequency of root resorption and the characteristics of malocclusion and marked occlusal attrition showed in individual teeth. The results were as follows. 1. All of the persons examined showed some evidence of root resorption in one or more of the permanent teeth, $35.84\%$ of the teeth examined and more frequent in female group than male group(p<0.01). 2. On the susceptibility of the root resorption in individual teeth in this study, the author found the mandibular incisors and the maxillary incisors, in the order named, to be most susceptible in all affected teeth, but maxillary central incisors, maxillary first bicuspids, and maxillary lateral incisors, in the order named, were more susceptible to marked root resolution. 3. The more proclined maxillary Incisors the more affected root resorption in four maxillary incisors and the more proclined mandibular incisors the more affected root resorption in four mandibular incisors. 4. Overbite more affected root resorption than overjet, and the higher tender to openbite the more frequent was root resorption. 5. On the characteristics of malocclusion showed in individual teeth, the openbite teeth combined with crossbite, were most frequent in root resolution.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.1
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• pp.70-78
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• 2016

Many types of orthopedic appliances have been developed and used for the treatment of class II malocclusion in pediatric dentistry. Headgear is one of the extraoral appliances, which is used for the purpose of preventing the overgrowth of maxilla. Hotz appliance is used in couple with a cervical headgear for the expansion of maxilla and retraction of maxillary incisors. This case report is about the orthodontic treatment of three patients with class II division I malocclusion. These young patients were given orthopedic treatment in combination with a cervical headgear and Hotz appliance. After the treatment using these extraoral and intraoral appliances, succeeding treatments were practiced considering individual needs as follows: fixed orthodontic appliance for mandibular anterior crowding, Class II activator for retention and additory orthopedic treatment and the retention with Hotz appliance. Young patients with Class II division I malocclusion reported in this study received the orthodontic treatment using a cervical headgear and Hotz appliance as well as appropriate succeeding treatment afterward. All patients received improved convex profiles and lip protrusions by retracting maxilla and maxillary incisors.

• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.159-174
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• 2000

Many treatment approaches of Cl III malocclusion have been introduced and the choice of treatment should be a function of the individual problem, not of the clinician(personal preference, experience and success rate of the operator). Therefore a function of the individual problem should be analysed exactly Much has been written in the orthodontic literature concerning the nature of Cl III malocclusion. It has been reported by many investigators that a Cl III malocclusion occurs in a variety of skeletal and dental configurations by differences of race and age. Lateral cephalometric radiographs of 125 individuals were studied for the presence and distibution of four horizontal components and one vortical component in a manner similar to McNamara. The results were as follows : 1. Cl III malocclusion is not a single clinical entity. It can result from numerous combinations of skeletal and dental components. 2. Maxillary skeletal retrusion was the most common single charateristic of the Cl III sample. 3. Only a small percentage of the cases in this study exhibited maxillary dentoalveolar protrusion. 4. Only a small percentage of the cases in this study exhibited mandibular dentoalveolar retrusion. 5. Mandible was usually well-positioned, but a wide variation was observed. 6. A large percentage of the cases in this study exhibited excessive vertical development. Thus, it appears that in designing the ideal treatment regime, those approaches which might restrict vertical development and promote maxillary horizontal growth could be more appropriate in many cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.3
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• pp.165-167
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• 2015

It has recently been reported that long-standing post-traumatic open bite can be successfully corrected with botulinum toxin type A (BTX-A) injection into the anterior belly of the digastric muscle (ABDM). The report documented an individual with bilaterally symmetrical and otherwise unremarkable anterior digastric musculature. However, the existence of variant anterior digastric musculature is common and may complicate the management of anterior open bite with BTX-A injection. Screening for variant ABDM can be accomplished via ultrasound, computed tomography, and magnetic resonance imaging. Screening for variant ABDM should be performed prior to BTX-A injection in order to account for musculature that may exert undesired forces, such as inferolateral deviation, on the anterior mandible in patients with anterior open bite.

• The Journal of the Korean dental association
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• v.57 no.6
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• pp.333-343
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• 2019

Many orthodontists face difficulties in aligning incisors in an esthetically critical position, because the individual perception of beauty fluctuates with time and trend. Temporary anchorage device (TAD) can aid in attaining this critical incisor position, which determines an attractive smile, the amount of incisor display, and lip contour. Borderline cases can be treated without extraction and the capricious minds of patients can be satisfied with regard to the incisor position through whole dentition distalization using TAD. Mild to moderate bimaxillary protrusion cases can be treated with TAD-driven en masse retraction without premolar extraction. Patients with Angle's Class III malocclusion can be the biggest beneficiaries because both sufficient maxillary incisal display, through intrusion of mandibular incisors, and distalization of the mandibular dentition are successfully achieved. In addition, TAD can be used to correct various other malocclusions, such as canting of the occlusal plane and dental/alveolus asymmetry.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.159-172
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• 2001

Three dimensional analysis of malocclusion and craniofacial deformation is essential for the successful orthodontic treatment. But the orthodontists are not familiar with diagnosis and treatment plane based on lateral cephalometric analysis. Since orthodontists do not posses a sufficient knowledge in standard value of posteroanterior cephalometric anaysis and of clinical importance for transverse jaw growth. In this study male(n=130) and female(n=171) aged from 6 to 16 and diagnosed as Class I malocclusion were selected to analysis width of cranium, maxilla and mandible on the posteroanterior cephalogram. The changes as a function of chronologic age and cervical vertebrae maturity index(CVXI) were examined. The Proper regression model was selected by sex with polynominal regression models and method of variable selection. Mean of each measurements and 70% confidence interval of individual measurement according to age was assesed and a graphs were made. Results are as follows :1. All the measurements for the width are gradually incresed as increase in chronologic age and CVMI. From the total amount of change between age 6 and 16, there is a tendency that mandibular width is broader than maxillary width and the width of male is broader than female. 2. There is no statistically significant sexual difference in Mx-Mn difference, Mx-Mn width differential, Mx/Mn ratio according to age and CVMI. 3. Mean of each measurement and 70% confidence interval of individual measurement according to age and sex were assessed and graphs were made for maxillary width, mandibular width, Mx-Mn difference, Mx/Mn ratio. 4. The width of maxilla and mandible in Korean children are broader than Western children during growth period.