• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1183-1188
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• 2005

In this paper, we propose a 3D automated measuring system which measures the mandibular movements and the reference plane of the jaw movements. In diagnosis and treatment of the malocclusions, it is necessary to estimate the mandibular movements and the reference plane of the jaw movements. The proposed system is configured with double stereo-cameras, PC, two moving pattern plates(MPPs), two fixed pattern plates(FPPs) and one orbital marker. The virtual pattern plate is applied to calculate the homogeneous transformation matrices which describe the coordinates systems of the FPP and MPP with respect to the world coordinates system. To estimate the parameters of the hinge axis, the Euler's theorem is applied. The hinge axis points are intersections between the FPPs and the hinge axis. The coordinates of a hinge axis point with respect to the MPP coordinates system are set up to fixed value. And then, the paths of the jaw movement can be calculated by applying the homogeneous transformation matrix to fixed hinge axis point. To examine the accuracy of the measurements, experiments of measuring the hinge axis points and floating paths of them are performed using the jaw motion simulator. As results, the measurement errors of the hinge axis points are within reasonable boundary, and the floating paths are very similar to the simulator's moving path.

• The korean journal of orthodontics
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• v.31 no.4 s.87
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• pp.415-424
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• 2001

Anchorage in orthodontics is very important factor for orthodontist to treat malocclusion from diagnosis and treatment planning to end of treatment. Skeletal anchorage like miniscrew is supposed to be more effective method in anchorage control than conventional anchorage which needs patient's good cooperation. So this article will be mentioned about various clinical application of miniscrew through the general investigation and case reports about orthodontic use of miniscrew, specially about screwing area and clinical consideration of miniscrew's screwing on midpalate. The changes of treatment philosophy and methods by using skeletal anchorage were summarized and following results were obtained. 1. The orthodontic anchorage changed from relative concept to absolute one. 2. Bodily movement of teeth gets easier and determinate force system is possible on biomechanical consideration. 3. Some part of treatment that needs surgical intervention is possible by just orthodontic treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.4
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• pp.168-174
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• 2013

Objectives: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. Results: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). Conclusion: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.57-63
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• 1975

For the purposes of augmentation of the aid for case analysis and diagnosis of malocclusion, a roentgenocephalometric study was made from 84 Korean adolescences. The Subjects consist of 42 males and 42 females aged from 17 to 20 years with normal occlusion and acceptable facial appearance. The author measured 18 angles and 14 linear distances as suggested by Jarabak. The following results were obtained. 1) Each linear measurement of the males' skull was greaten than that of the females. 2) The posterior to anterior facial height was $69.2\%$ in the males and $67.1\%$ in the females. 3) In the relationship of upper lip to esthetic line, the lip of females was more behind than that of males. 4) Saddle angle was $124.7^{\circ}$, articular angle was $148.7^{\circ}$, genial angle was $119.4^{\circ}$ and upper and lower genial angles were $45.1^{\circ}\;(N-Go-a^{\circ})$ and $74.2^{\circ}\;(N-Go-Me^{\circ})$. 5) The ratio of mandibular body to anterior cranial base was about 1:1. 1. 6) The angulations of $SNA^{\circ},\;SNB^{\circ}\;and\;SNP^{\circ}$ were as follows; $SNA^{\circ},\;80.3^{\circ},\;SNB^{\circ},\;79.8^{\circ},\;SNP^{\circ},\;81.1^{\circ}$. 7) The angle of the sella-nasion plane to the mandibular plane $(SNG^{\circ}Me^{\circ})$ was $32.0^{\circ}$ and that of the occlusal plane to the mandibular plane was $18.2^{\circ}$. 8) The angle of the maxillary central incisor to the sellanasion plane $(1-SN^{\circ})$ was $105.6^{\circ}$. That of the mandibular central incisor to the mandibular plane $(1-GoMe^{\circ})$ was $94.0^{\circ}$, and the interincisal angle $(1\;to\;1^{\circ})$ was $127.6^{\circ}$. 9) The linear distance from incisal edge of upper central incisor to facial plane was 8.0mm and that of lower central incisor was 4.6mm. 10) In the relationship of the lower lip to the esthetic line, the lower lip was 0.2mm front of the esthetic line.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.110-120
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• 2020

Although not all kinds of deep bite occlusions are considered pathological states, they can cause persistent wear and eruption of the anterior mandibular teeth if the anterior occlusal contact is unstable or accompanied by an occlusal disharmony. The patient was a 72-year-old man with no occlusal contact of the remaining anterior teeth in the centric relation position because of a skeletal class II malocclusion and loss of occlusal support. If the vertical dimension needs to be increased for prosthetic restoration in a patient with a deep bite, the amount of vertical dimension increase must be determined through precise diagnosis. This is because the overjet may increase and cause an unstable occlusion. In this review, we report the case of a patient with a stable occlusion and good treatment results achieved by using a removable partial denture prosthesis and applying the Dahl concept.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.113-124
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• 1996

The purpose of this report is to present the successful improvement of occlusal relationship and facial estherics in Class II div.1 malocclusion by orthodontic treatment with upper first premolars and lower second premolars extracted. Before treatment, the patients showed Class II div. 1 relation with severe overjet. deep overbite, large ANB angle, retrusive mandible and a convex soft tissue profile. After treatment, normal canine and molar relationships were obtained. Facial esthetics were improved. There were no mesial tipping of lower first molars and root resorptions. With the adequate diagnosis and treatment plan and biomechanics, the application of upper first and lower second premolar extraction may be one of good strategies in some Class II cases treatment.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.991-999
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• 1998

Tooth impaction may lead to malocclusion, root resolution, cyst or aberrant changes in adjacent teeth. Clinical and radiographic examinations are used to locate the impaction, and appropriate treatment plans must be made to relocate the impacted tooth. When surgically exposing the impacted tooth, periodontal considerations to conserve maximum amount of soft and hard tissue are used. Oral hygiene instructions are emphasized to maintain sound periodontal health. Securing enough space for the impacted tooth and proper anchorage is important. Proper use of force and mechanics is crucial to prevent such complications as root resolution. Various patterns of orthodontic traction may be employed as situation permits. Most impaction cases can be managed with orthodontic traction to restore function and esthetics, provided that early detection and proper diagnosis and treatment planning are made.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.1
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• pp.79-87
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• 2017

The open bite malocclusion is a common clinical entity and has multifactorial causes. Development of effective treatment plan and management is dependent on proper diagnosis. The skeletal open bite patient requires a coordinated orthodontic and orthognathic surgical approach to achieve stable occlusion, acceptable esthetics, and improved function. But in case of open bite with severely decayed dentition, restoration in the entire dentition is necessary. Using the facial analysis and diagnostic wax-up, the most effective treatment was prosthetic rehabilitation. The provisional restorations were fabricated to satisfy esthetic and functional requirements, which result in the uniformly distributed occlusal force, anterior and canine guidance. The inter-arch relationship, labio-dental harmony, and the soft tissue aspect, which is important to estimate the longevity were evaluated. Definitive restorations of monolithic zirconia were made by replicating provisional restorations by using the latest CAD/CAM technology. They were delivered to the patient and clinical follow-up observation was satisfactory.

• The korean journal of orthodontics
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• v.43 no.1
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• pp.42-52
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• 2013

The aim of this paper was to propose a new method of bimaxillary orthognathic surgery planning and model surgery based on the concept of 6 degrees of freedom (DOF). A 22-year-old man with Class III malocclusion was referred to our clinic with complaints of facial deformity and chewing difficulty. To correct a prognathic mandible, facial asymmetry, flat occlusal plane angle, labioversion of the maxillary central incisors, and concavity of the facial profile, bimaxillary orthognathic surgery was planned. After preoperative orthodontic treatment, surgical planning based on the concept of 6 DOF was performed on a surgical treatment objective drawing, and a Jeon's model surgery chart (JMSC) was prepared. Model surgery was performed with Jeon's orthognathic surgery simulator (JOSS) using the JMSC, and an interim wafer was fabricated. Le Fort I osteotomy, bilateral sagittal split ramus osteotomy, and malar augmentation were performed. The patient received lateral cephalometric and posteroanterior cephalometric analysis in postretention for 1 year. The follow-up results were determined to be satisfactory, and skeletal relapse did not occur after 1.5 years of surgery. When maxillary and mandibular models are considered as rigid bodies, and their state of motion is described in a quantitative manner based on 6 DOF, sharing of exact information on locational movement in 3-dimensional space is possible. The use of JMSC and JOSS will actualize accurate communication and performance of model surgery among clinicians based on objective measurements.

• The Journal of the Korean dental association
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• v.45 no.8 s.459
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• pp.483-490
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• 2007

The aim of this study was to investigate the relationship between the mandibular antegonial notch and the mandibular morphology, and the curve of Spee in anteroposterior skeletal relationship. Pre-treatment lateral cephalograms were obtained from 80(male 34, female 46) adult orthodontic patients and the samples were classified into 3 categories by ANB angle($0^{\circ}$$\leq$ANB< $4^{\circ}$ Class I, $4^{\circ}$$\leq$ANB Class II, ANB< $0^{\circ}$ Class III). The curve of Spee was measured directly from the pre-treatment mandibular study cast of each patient included in this study. Pearson correlation coefficient test and multiple regression analysis in each group revealed the following results; 1. Antegonial notch depth was positively correlated with hoth lower anterior facial height(ANS-Me) in skeletal Class I, II and III groups and Id-Me height in skeletal Class I and II groups. 2. A statistically significant negative correlation was found between the depth of the antegonial notch and the curve of Spee in the Class III group. 3. Significant relationship was not found between the antegonial notch depth and any of the other cephalometric variables such as mandibular body length(Go-Gn) and ramus height(Co-Go). As antegonial notch depth increased, more vertical growth of the mandible was observed. Antegonial notch can be used as a predictor of vertical mandibular growth in the diagnosis and treatment planning of malocclusion.