• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.17.1-17.11
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• 2020

Background: To evaluate the facial asymmetry, three-dimensional computed tomography (3D-CT) has been used widely. This study proposed a method to quantify facial asymmetry based on 3D-CT. Methods: The normal standard group consisted of twenty-five male subjects who had a balanced face and normal occlusion. Five anatomical landmarks were selected as reference points and ten anatomical landmarks were selected as measurement points to evaluate facial asymmetry. The formula of facial asymmetry index was designed by using the distances between the landmarks. The index value on a specific landmark indicated zero when the landmarks were located on the three-dimensional symmetric position. As the asymmetry of landmarks increased, the value of facial asymmetry index increased. For ten anatomical landmarks, the mean value of facial asymmetry index on each landmark was obtained in the normal standard group. Facial asymmetry index was applied to the patients who had undergone orthognathic surgery. Preoperative facial asymmetry and postoperative improvement were evaluated. Results: The reference facial asymmetry index on each landmark in the normal standard group was from 1.77 to 3.38. A polygonal chart was drawn to visualize the degree of asymmetry. In three patients who had undergone orthognathic surgery, it was checked that the method of facial asymmetry index showed the preoperative facial asymmetry and the postoperative improvement well. Conclusions: The current new facial asymmetry index could efficiently quantify the degree of facial asymmetry from 3D-CT. This method could be used as an evaluation standard for facial asymmetry analysis.

• Journal of Technologic Dentistry
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• v.23 no.1
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• pp.95-106
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• 2001

The purpose of this study was to show the method of three-dimensional morphometry developed recently and to compare the accuracy of three-dimensional morphometry with those of PA cephalometry, The three-dimensional morphometry analysis program and device were developed. Steel balls (1.2mm in diameter) were attached in twenty five landmarks of artificial human skull. This artificial human skull was used as experimental materials. From three-dimensional morphometry and PA cephalometry of artificial human skull. eleven linear measurements were acquired and made into asymmetry index. Right-left differences of measurements were used as asymmetry index. These measurements and asymmetry index were compared respectively with those of actual. The results were as follows: 1. Mean difference between three-dimensional morphometry and actual artificial human skull in linear measurements was $1.99{\pm}0.37mm$, and mean difference between PA cephalometry and actual was $21.12{\pm}0.45mm$. Both of all were reduced more than those of actual. 2. Mean difference between three-dimensional morphometry and actual artificial human skull in asymmetry index was $0.07{\pm}0.42$, and mean difference between PA cephalometry and actual was $3.63{\pm}0.60$. Three-dimensional morphometry was reduced while PA cephalometry was magnified more than that of actual. 3. Each eleven asymmetry index of three-dimensional morphometry was the same negative sign as those of actuals while only N-Z, ANS-J, Tr-Go, Tr-ANS asymmetry index were the same in PA cephalometry. These results suggest that the method of three-dimensional morphometry is more accurate than those of PA cephalometry in asymmetry analysis.

• Journal of Oral Medicine and Pain
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• v.39 no.3
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• pp.100-106
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• 2014

Purpose: This study was performed to investigate the relationship between temporomandibular disorders (TMDs) and the asymmetry of the mandibular height. Methods: We compared 100 randomly selected TMD patients diagnosed by the research diagnostic criteria for TMD (RDC/TMD) Axis I with 100 non-TMD control subjects matched with the TMD patients in age and gender. The mandibular heights were measured on an orthopantomogram and the asymmetry index (AI) was calculated as previously described. Results: The absolute AI value of 4.37% turned out to be the least cut-off value defining asymmetry, which showed a significant difference in asymmetry incidence (p<0.01) between the TMD and control groups. The risk of TMD increased in the asymmetry group by 4.57 (odds ratio). The incidence of asymmetry was not related to age and gender in both of the TMD and control groups. When dividing the TMD group according to the RDC/TMD Axis I diagnosis, neither the incidence of muscle disorder nor disk displacement was related to the incidence of asymmetry. However, a higher incidence of asymmetry was observed in the subjects classified into the arthrosis/arthritis groups (p<0.01). Conclusions: Although it does not imply a direct cause-and-effect relationship, asymmetry resulting in more than 4.37% difference between mandibular heights may increase the risk of TMD and correlates positively to the incidence of arthritic change in the temporomandibular joint of TMD patients.

• The Korean Journal of Financial Management
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• v.26 no.3
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• pp.65-101
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• 2009

The effects of program trading halts system (sidecar) on information asymmetry of program trading stocks, index arbitrage stocks, and non-index arbitrage stocks in the Korean stock market are examined. Effective spread and number of program trade of each stock are used as proxy variables for information asymmetry. The main results are as follows; Firstly, we find that effective spreads of program trading stocks in the post-halt period decrease significantly following the halt period. This means that sidecar has the effect of reducing information asymmetry in the Korean stock market. Secondly, the mitigation effect of information asymmetry of program trading stocks works only in buy-program trading stocks, but not in sell-program trading stocks. Thirdly, the results show that there are no distinct differences for index arbitrage group and non-index arbitrage group surrounding the sidecar events. In other words, program trading halts system has a mitigating effect of information asymmetry in not only index arbitrage trading stocks but also non-index arbitrage stocks. Fourthly, this mitigation effect works only in buy-sample not in sell-sample like in program trading stocks. And lastly, the analyses result of number of program trade shows that number of program trade of almost of sample stocks increases after the sidecar events. This implies that the information asymmetry is not fully resolved during the halt period and the effect of news inducing sidecar is continuing after the event.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.45-51
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• 2007

Purpose : This study aimed to identify the range of normal facial asymmetry using three-dimensional CT and to develop a simple method of diagnosis of facial asymmetry. Materials and Methods : Twenty eight adults with normal occlusion (16 males and 12 females; mean age 24 years and 1 month) were selected whose faces were assessed to be symmetric by an orthodontist. Three-dimensional reconstructions were obtained utilizing spiral CT scans and an oral and maxillofacial radiologist evaluated nineteen anatomic landmarks in three-dimensional coordinates. Facial asymmetry index of each landmark was caluculated. Results : The range of normal facial asymmetry of each landmark was identified using mean and standard deviation of facial asymmetry index. Conclusions : The range of normal facial asymmetry identified in this study may be used as a diagnostic standard for facial asymmetry analysis.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.2
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• pp.205-212
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• 2012

Purpose : The aim of this study was to investigate the relationship between weight-supporting asymmetry and gait symmetry in patients with stroke. Methods : Sixty two stroke patients with hemiplegia stood quietly with eye opens on a force platform to calculate weight-supporting asymmetry from vertical reaction force. The GAITRite was used to evaluate their gait parameters. The data were analyzed using Pearson correlation. Results : The results of this study was showed that the medio-lateral index (ML) was correlated with symmetry rate (SR), symmetry index (SI), and Gait asymmetry (GA) of step time and length but stronger correlation with spatial gait symmetry than temporal symmetry. In gait symmetry, step length has stronger correlation with weight-supporting asymmetry than step time. Conclusions : The results of this study shows weight-supporting asymmetry was correlated with more spatial gait symmetry than temporal symmetry.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.1
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• pp.59-69
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• 2011

Purpose : The purposes of this study were to find correlations among Fugl-Meyer Assessment Scale, walking velocity, walking asymmetry and balance ability. Methods : The study sample consisted of 50 stroke patients referred to the Department of Rehabilitation Medicine in the Sanggye Paik, Ilsan Paik, Seoul Paik, and Dobong Hospital. All subjects were ambulatory with or without an assistive device. All participants were assessed on Fugl-Meyer Assessment scale and walking velocity, walking asymmetry. The data were analyzed using independent t-test, ANOVA, and multiple regression. Results : The results revealed that upper extremity coordination, balance and pain items of Fugl-Meyer Assessment scale were significantly correlated with walking velocity and upper extremity and upper extremity motor and balance items of Fugl-Meyer Assessment scale were significantly correlated with walking asymmetry. Fugl-Meyer Assessment scale was not significantly correlated with Static Balance Index, Dynamic Balance Index and Weight Distribution Asymmetry Index. Their power of explanation regarding comfortable walking velocity and comfortable walking asymmetry were 60.3%, 42.5% respectively. Conclusion : These results showed that Fugl-Meyer Assessment scale is significantly correlated with walking velocity, asymmetry and not significantly correlated with balance ability. Therefore Fugl-Meyer Assessment scale is an appropriate assessment tool to predict walking ability of patients with stroke. Futher study about walking velocity and asymmetry by change of Fugl-Meyer Assessment scale is needed using a longitudinal study design.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.126-135
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• 2018

This study examined whether the difference in the middle cerebral artery (MCA) velocities can predict the prognosis of stroke and whether the prognostic impact differs among stroke subtypes. Transient ischemic attack (TIA) or acute ischemic stroke patients, who underwent a routine evaluation and transcranial Doppler (TCD), were included in this study. The MCA asymmetry index was calculated using the relative percentage difference in the mean flow velocity (MFV) between the left and right MCA: (|RMCA MFV-LMCA MFV|/mean MCA MFV)${\times}100$. The stroke subtypes were determined using the TOAST classification. Poor functional outcomes were defined as a mRS score ${\geq}3$ at 3 months after the onset of stroke. A total of 988 patients were included, of whom 157 (15.9%) had a poor functional outcome. Multivariable analysis showed that only the MCA asymmetry index was independently associated with a poor functional outcome. ROC curve analysis showed that adding the MCA asymmetry index to the prediction model improved the discrimination of a poor functional outcome from acute ischemic stroke (from 88.6% [95% CI, 85.2~91.9] to 89.2% [95% CI, 85.9~92.5]). The MCA asymmetry index has an independent prognostic value for predicting a poor short-term functional outcome after an acute cerebral infarction. Therefore, TCD may be useful for predicting a poor functional outcome in patients with acute ischemic stroke.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.4
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• pp.694-702
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• 1995

When a small absorbing particle is exposed to a strong thermal radiation incidence, it moves towards or away from the radiation source due to the nonuniform internal absorption of the radiation. It is called the photophoretic phenomena and governed by the asymmetry factor. An asymmetry factor for the total wavelength range is calculated to estimate the photophoretic phenomena of a particle in a combustor or in the atmosphere and compared to that for a single wavelength. The samples are soot particulates, water droplets, ice particles, silicon particles, $SiO_2$ particles, aluminium oxide particles, whose spectral complex refractive index are available. Although differences between total and monochromatic asymmertry factors are not much for relatively uniform distribution of the spectral refractive index, they are great in general. Therefore the use of the monochromatic factor will considerably deteriorate the accuracy of the calculation of the photophoresis.

• The Korean Journal of Zoology
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• v.30 no.1
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• pp.44-52
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• 1987

The spontaneous bilateral asymmetry was analyzed in the hermaphroditic fish Rivulus marmoratus to obtain base line data on the developmental stability of this fish. The results obtained were as follows; 1. Eight kinds of countable anatomical characters except numbers of otolith and radii branchiostegi showed bilateral asymmetry at the frequency ranging from 9.8% to 64.7%. 2. Asymmetry index was not significantly different from that of gonochoristic fish species previously reported. Genetical implication of the results was discussed in relation to developmental stability and homozygosity of this species.