• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권1호
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• pp.55-61
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• 2011

Conventional slinding genioplsty has the risk of mental nerve injury after operation and difficult to correct vertical asymmetry of chin. So, authors propose a new genioplasty to correct asymmetry of chin. Switching genioplasty is a modification method of conventional genioplasty. Between mandibular right and left canine, osteotomy line of triangular shape make until mandibular lower border. In large side, osteotome line of wedge shape is added to reduction. After osteotomy, segment of wedge shape was separated from chin. Distal segment was rotated to reduction side. Because of rotation of distal segment, space is made in opposite side. Seperated segement of wedge shape from large side is switched this space to fill. So, stability of distal segment is achieved. Authors applied to swiching genioplasty the patients who was remained the chin asymmetry after both sagittal split ramus osteotome was done because mandible asymmetry. After operation, patient and operator were satisfied with excellent esthetic results without any other complication. The switching genioplasty is effective surgical technique for chin asymmetry because it has more advantages than conventional sliding genioplasty. First, other donor side does not need for bone graft. Second, the switching genioplasty can reduce infection, bone resroption, dehiscence, capsular contraction after allograft. Third, have little mental nerve damage. Forth, anteroposterior correction is possible. Fifth, operation time is less than other genioplasty for chin asymmetry.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.57.1-57.8
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• 2019

Background: The relationship between the lateral deviation of chin and the upper and middle facial third asymmetry is still controversial. The purpose of this study is to evaluate the correlation of upper and middle facial third asymmetry with lateral deviation of chin using 3-dimensional computed tomography. The study was conducted on patients who underwent orthognathic surgery from January 2016 to August 2017. A total of 40 patients were included in this retrospective study. A spiral scanner was used to obtain the 3-dimensional computed tomography scans. The landmarks were assigned on the reconstructed 3-dimensional images, and their locations were verified on the axial, midsagittal, and coronal slices. The Pearson correlation analysis was performed to evaluate the correlation between chin deviation and difference between the measurements of distances in paired craniofacial structures. Statistical analysis was performed at a significance level of 5%. Results: In mandible, the degree of chin deviation was correlated with the mandibular length and mandibular body length. Mandibular length and mandibular body length are shorter on the deviated-chin side compared to that on the non-deviated side (mandibular length, r = -0.897, p value < 0.001; mandibular body length, r = -0.318, p value = 0.045). In the upper and middle facial thirds, the degree of chin deviation was correlated with the vertical asymmetry of the glenoid fossa and zygonion. Glenoid fossa and zygonion are superior on the deviated-chin side than on the non-deviated side (glenoid fossa, r = 0.317, p value = 0.046; zygonion, r = 0.357, p value = 0.024). Conclusion: Lateral deviation of chin is correlated with upper and middle facial third asymmetry as well as lower facial third asymmetry. As a result, treatment planning in patients with chin deviation should involve a careful evaluation of the asymmetry of the upper and middle facial thirds to ensure complete patient satisfaction.

• 대한치과보철학회지
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• 제22권1호
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• pp.72-78
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• 1984

The notion that the axis of the shaft of the articulator must coincide the patient's mandibular transverse axis tells us the importance of locating the axis precisely. When using kinematic axis to transfer a cast to an articulator, the anatomic asymmetry of the contralateral points will result in certain distortion when the axis transferred to an articulator where the mechanical axis produces symmetry. In this study, after locating the true hinge axis point with Denar hinge axis locator, the discrepancies between true hinge axis point and arbitrary hinge axis point that was 13mm anterior from the posterior margin of center of trangus to the outer canthus of eye were measured. And the discrepancies between left and right true hinge axis point in the superoinferior and anteroposterior directions were measured. For this study, 20 dental students who have no missing teeth and no difficulties of mandibular movement were selected. Upper and lower cast of subjects were mounted on Denar Mark II articulator uisng Denar Slidematic face-bow and centric relation record for the measurement of discrepancies between left and right true hinge axis points. The results obtained as follows. 1. The mean distance from the arbitrary hinge axis point to the true hinge axis point was as follows. Right: horizontal distance; 1.99mm, vertical distance; 2.12mm, linear distance; 3.36 mm. Left: horizontal distance; 1.39mm, vertical distance; 2.06mm, linear distance; 2.09mm. Total: horizontal distance; 1.69mm, vertical distance; 2.09mm linear distance; 3.06 mm. 2. The 87.5% of true hinge axis points were within 5mm of the arbitrary hinge axis point. 3. The mean discrepancies between the right and left hinge axis point were 2.92mm in superoinferior direction and 4.74mm in anteroposterior direction. 4. When transferring the axis to the articulator, anatomic asymmetry between right: and left axis point produces in dislocation of cast on the articulator, and undesirable shift in esthetic tooth position will be resulted.

• Structural Engineering and Mechanics
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• 제2권2호
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• pp.211-225
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• 1994

Responses of asymmetrical multistorey buildings to earthquakes are obtained by quasi-static code approach and real time dynamic analysis, using two different structural models. In the first model, all vertical members are assumed to be restrained at the slab levels and hence their end rotations, about horizontal axes, are taken as zero. In the second model this restriction is removed and the rotation is assumed to be proportional to the lateral stiffness of the member. A simple microcomputer based procedure is used in the analyses, by both models. Numerical examples are presented where results obtained from both the models are given. Effects of modelling on the response of three buildings, each with a different type and degree of asymmetry, are studied. Results for deflections and shear forces are presented and the effects of the type of model on the response are discussed.

• 천문학회보
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• 제44권2호
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• pp.49.1-49.1
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• 2019

I present the mean metallicity distribution of stars in the Milky Way based on photometry from the Sloan Digital Sky Survey. I utilize an empirically calibrated set of stellar isochrones developed in previous work to estimate the metallicities of individual stars to a precision of 0.2 dex for reasonably bright stars across the survey area. I also obtain more precise metallicity estimates using priors from the Gaia parallaxes for relatively nearby stars. Close to the Galactic mid-plane (|Z| < 2 kpc), a mean metallicity map reveals deviations from the mirror symmetry between the northern and southern hemispheres, displaying wave-like oscillations. The observed metallicity asymmetry structure is almost parallel to the Galactic mid-plane, and coincides with the previously known asymmetry in the stellar number density distribution. This result reinforces the previous notion of the plane-parallel vertical waves propagating through the disk, which have been excited by a massive halo substructure such as the Sagittarius dwarf galaxy plunging through the Milky Way's disk. This work provides evidence that the Gaia phase-space spiral may continue out to |Z| ~ 1.5 kpc.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권3호
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• pp.233-240
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• 2007

Osteochondroma is a common benign tumor of the axial skeleton, especially the distal metaphysis of the femur and proximal metaphysis of the tibia. However, it occurred rarely on the facial skeleton. The coronoid and condylar processes have been considered to be the most common sites of occurrence for osteochondroma of the facial skeleton. The first treatment of osteochondroma is condylectomy, whereas extirpation was done by excision with condyle salvage. Condylectomy presents decrease of vertical dimension, jaw deviation, malocclusion. So, reconstruction is need. Methods of reconstruction are as follows: no reconstruction, condyloplasty, discectomy, costochondral graft, discplication or coronoidectomy, eminoplasty, alloplastic spacer placement, Le Fort I level maxillary osteotomy, extraoral and intraoral vertical ramus osteotomy. This is a case report of a 28-year old woman who had facial asymmetry, malocclusion and temporomandibular joint pain. We obtained moderate functional and cosmetic results with surgical removal of the osteochondroma by condylectomy and concomitant reconstruction of condyle by vertical ramus osteotomy with sliding technique.

• 한국운동역학회지
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• 제18권1호
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• pp.169-178
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• 2008

본 연구는 계단 보행 중 연속적인 두 스텝의 3차원적 지면반력 파라미터를 제공하고, 계단의 너비에 따른 지면 반력 파라미터의 차이 및 비대칭성과 일관성을 규명하는데 있다. 10명의 성인 대상자가 본 실험에 참여하였으며, 각 10번의 평지, 상향 및 하향보행을 3가지의 다른 너비의 계단에서 실시하였다. 본 연구를 수행한 결과 다음과 같은 결론을 얻었다. 첫째, 계단의 너비는 대부분의 지면반력 파라미터들의 패턴이나 일관성, 비대칭지수에 영향을 미치지 않았다. 둘째, 평지 보행과 계단보행은 지면반력 파라미터의 패턴에서 큰 차이를 보였다. 평지보행과 상향보행은 Fz1, Fz2, 그리고 Fz3로 구성되는 "M" 형태를 보인 반면에 하향보행에서는 Fz2가 거의 없고 큰 Fz1과 작은 Fz3로 구성된 패턴을 보였다. 또한 계단 보행은 평지보행과 매우 다른 전 후 지면반력 패턴을 보였다. 즉 상향보행은 Fy1이 존재하지 않는 패턴을, 하향보행은 Fy2가 존재하나 매우 작은 크기를 보였다. 셋째, 계단보행의 수직 지면반력 파라미터들은 적용가능한 일관성 지수 및 비대칭 지수를 나타내었다.

• 대한치과교정학회지
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• 제47권1호
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• pp.50-58
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• 2017

Introduction: Identifying menton (Me) on posteroanterior cephalograms and three-dimensional (3D) cone-beam computed tomography (CBCT) images is difficult, because the midpoint of the symphyseal area is not identifiable after the mandibular symphysis fuses at an early age. The aim of this study was to evaluate the reliability of the identification of the genial tubercle (GT) in patients with mandibular asymmetry and to compare it with that of the traditional landmark, Me. Methods: The samples comprised 20 CBCT images of adults with mandibular asymmetry. Two examiners performed the identifications and measurements. Me and GT were marked, and the anteroposterior, vertical, and transverse distances to the three reference planes were measured on 3D-reconstructed CBCT images. The intra- and inter-examiner reliability of landmark identification of Me and GT were assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Results: The Me and GT landmarks showed excellent reliability ($ICC{\geq}0.993$) three-dimensionally. In the transverse evaluation, the ICC values of the GT (range, 0.997-0.999) tended to be slightly higher than those of Me (range, 0.993-0.996). In the Bland-Altman plots for the two separate assessments, Me showed a maximum error of 1.76 mm in the transverse direction, whereas the GT showed a maximum error of 0.96 mm in the 95% limit. Conclusions: Our results suggest that both Me and GT are clinically reliable and equally useful landmarks for the evaluation of mandibular asymmetry on CBCT images.

• 대한치과교정학회지
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• 제52권3호
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• pp.172-181
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• 2022

Objective: The objectives of this study were to compare the time-dependent changes in occlusal contact area (OCA) and bite force (BF) of the deviated and non-deviated sides in mandibular prognathic patients with mandibular asymmetry before and after orthognathic surgery and investigate the factors associated with the changes in OCA and BF on each side. Methods: The sample consisted of 67 patients (33 men and 34 women; age range 15-36 years) with facial asymmetry who underwent 2-jaw orthognathic surgery. OCA and BF were taken before presurgical orthodontic treatment, within 1 month before surgery, and 1 month, 3 months, 6 months, 1 year, and 2 years after surgery. OCA and BF were measured using the Dental Prescale System. Results: The OCA and BF decreased gradually before surgery and increased after surgery on both sides. The OCA and BF were significantly greater on the deviated side than on the non-deviated side before surgery, and there was no difference after surgery. According to the linear mixed-effect model, only the changes in the mandibular plane angle had a significant effect on BF (p < 0.05). Conclusions: There was a difference in the amount of the OCA and BF between the deviated and non-deviated sides before surgery. The change in mandibular plane angle affects the change, especially on the non-deviated side, during the observation period.

• 대한치과교정학회지
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• 제36권3호
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• pp.218-227
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• 2006

안면 비대칭 환자의 진단분석에 이용할 수 있는 이하두정 두부방사선 규격사진과 표면 근전도 검사 자료는 통용화된 진단분석법 부재 등의 이유로 제한적으로 사용되고 있다. 그러나 여타 진단분석법과 비교할 때, 수직 안모 유형의 평가 등 차별적인 정보를 얻을 수 있어 이에 대한 연구가 필요하리라 보인다. 본 연구의 목적은 안면 비대칭을 보이는 60명을 대상으로 이하두정 두부방사선 규격사진 및 저작근의 표면 근전도를 측정하여 수직 안모 유형과의 연관성 및 안면 비대칭과의 연관성을 평가하고자 함이다. 이하두정 두부방사선 규격사진 계측치 중 radiographic corpus length는 비편위측이 큰 값을 보였고 (p<0.001), 유의성은 없었으나 gonion to interspinosum axis는 편위측이 크고, gonion과 하악과두의 위치는 비편위측이 편위측에 비해 전방에 위치하였다 (p=0.07). 안정시 편위측 전측 두근의 근활성은 비편위측보다 높은 것으로 나타났다 (p<0.01). 또한 최대 폐구 시 교근의 활성은 유의성이 없었으나 비편위측에 비해 편위측이 큰 값을 보였다 (p<0.09). Facial index와 intercondylar axes angle은 양의 상관관계를 보였다 (p<0.01). 최대 폐구 시 편위측 및 비편위측의 교근의 활성은 facial index와 양의 상관관계를 보였다 (p<0.05). 이상의 결과를 통해 골격성 안면 비대칭을 보이는 환자에서 이하두정 두부방사선 규격사진과 표면 근전도 검사를 통해 비대칭 양상의 평가와 더불어 수직 안모 유형의 평가 또한 가능한 것으로 생각된다.