• Archives of Plastic Surgery
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• v.44 no.4
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• pp.332-336
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• 2017

Background Little is known concerning hair diameter variation within the safe donor area for hair transplantation surgery. Thicker or thinner hair may be needed, depending on the recipient area, hairline design, and the purpose of surgery. Methods Twenty-seven patients (7 men and 20 women; mean age, 28 years; range, 20-47 years) were included in this study. The midoccipital point was used as the reference point on the horizontal plane at the upper border of the helical rim. The target area width was 15 cm (7.5 cm to the right and left of the reference point) and the height was 8 cm (2 cm above and 6 cm below the reference point). The study area was divided horizontally into 3 5-cm sections (A, B, C) and vertically into 4 2-cm sections (1-4), creating a total of 12 zones. Ten anagen hairs were randomly obtained from each zone and their diameters were measured. Results Hair diameter in the 4 vertical sections varied significantly, gradually decreasing from sections 1 (superior) to 4 (inferior) in all 3 horizontal sections (A, B, and C). Conclusions Our results suggest that sections 1 and 2 of the occipital safe donor area would be useful for obtaining thicker hair, such as in procedures to treat male- and female-pattern hair loss, whereas hair from zones 3 and 4 could be useful for transplantation surgery requiring thinner hair, such as eyebrows, eyelashes, and female hairline correction. Our results may be clinically valuable for planning hair transplant surgery and choosing the optimal donor region.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.6
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• pp.427-435
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• 2022

Background: This study aimed to investigate the relationship between pharyngeal morphology and the success or failure of blind nasotracheal intubation using standard lateral cephalometric radiography and to analyze the measurement items affecting the difficulty of blind nasotracheal intubation. Methods: Assuming a line perpendicular to the Frankfort horizontal (FH) plane, the reference point (O) was selected 1 cm above the posterior-most end of the hard palate. A line passing through the reference point and parallel to the FH plane is defined as the X-axis, and a line passing through the reference point and perpendicular to the X-axis is defined as the Y-axis. The shortest length between the tip of the uvula and posterior pharyngeal wall (AW), shortest length between the base of the tongue and posterior pharyngeal wall (BW), and width of the glottis (CW) were measured. The midpoints of the lines representing each width are defined as points A, B, and C, and the X and Y coordinates of each point are obtained (AX, BX, CX, AY, BY, and CY). For each measurement, a t-test was performed to compare the tracheal intubation success and failure groups. A binomial logistic regression analysis was performed using clinically relevant items. Results: The items significantly affecting the success rate of blind nasotracheal intubation included the difference in X coordinates at points A and C (Odds ratio, 0.714; P-value, 0.024) and the ∠ABC (Odds ratio, 1.178; P-value, 0.016). Conclusion: Using binomial logistic regression analysis, we observed statistically significant differences in AX-CX and ∠ABC between the success group and the failure group.

• The Journal of Advanced Prosthodontics
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• v.8 no.2
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• pp.125-130
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• 2016

PURPOSE. The purpose of this study was to determine the effect of changes in the horizontal plane angle on the mesiodistal width ratios of the maxillary anterior teeth during the acquisition of frontal view photographs, derive these ratios for Korean adults on the basis of the data obtained, and analyze them using the Golden Proportion as a reference. MATERIALS AND METHODS. In experiment I, 30 plaster casts were mounted on an articulator and positioned on the angle-measuring device with a center setting of $0^{\circ}$. The device was rotated to $10^{\circ}$ in $1^{\circ}$ increments in a counterclockwise direction. At each angle, photographs were obtained and analyzed. Experiment II was based on 60 patients who visited the Department of Prosthodontics at Kyungpook National University Dental Hospital from February 2012 to February 2015. The patients were divided into three groups [Male (M), Female (F), Total (M + F)]. Frontal views were obtained for all groups and analyzed. RESULTS. From $1^{\circ}$ to $10^{\circ}$, the relative mesiodistal width ratios for the maxillary anterior teeth showed no significant differences from those at $0^{\circ}$. In all three groups, the relative width ratio of the maxillary central incisor was smaller than that specified in the Golden Proportion; the opposite was true for the canine. CONCLUSION. Our results suggest that the mesiodistal width ratios of the maxillary anterior teeth do not follow the Golden Proportion in Korean adults, and that a change in the horizontal plane angle from $1^{\circ}$ to $10^{\circ}$ during frontal photography does not affect these ratios.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.397-405
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• 1999

Purpose: To clarify the usefulness and the limitation of Digora system/sup (R)/ by evaluating the physical characteristics as the quantitative image on Image Plate(Ip). Materials and Methods: Radiograms were taken by Heliodent MD(Siemens Co.. Germany) with the image plate for adult. Cu-step wedge as reference material. and three pieces of dry mandibular bone. Image analysis was performed by single color enhancement. density measurement with histogram. The relationship between the exposure conditions and the distribution of the pixel values of the image. the variation of pixel values of each step of Cu-step wedge at two different area and Cu-equivalent value of three pieces of dry mandibular bone measure by the conversion equation. Results: There was no linear relationship between the exposure condition and the average pixel value of the image. of which the distribution was not even. The pixel value differences between the center portion and the periphery were ranged from 60 to 70 in vertical plane and from 15 to 26 in horizontal plane. Two plot profile formed at two different areas of the Cu-step wedge were different. The measured Cu-equivalent values showed the discrepancy among the times of measurement. Conclusion: As above results. Image Plate(Ip) of Digora system/sup (R)/ showed the limitation as the quantitative image. The physical property of IP was expected to need to be compensated for the quantitative evaluation of the bone or others

• New & Renewable Energy
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• v.20 no.1
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• pp.102-109
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• 2024

The Typical Meteorological Year (TMY) dataset compiles 12 months of data that best represent long-term climate patterns, focusing on global horizontal irradiance and other weather-related variables. However, the irradiance measured on the plane of the array (POA) shows certain distinct distribution characteristics compared with the irradiance in the TMY dataset, and this may introduce some biases. Our research recalculated POA irradiance using both the Isotropic and DIRINT models, generating an updated dataset that was tailored to POA characteristics. Our analysis showed a 28% change in the selection of typical meteorological months, an 8% increase in average irradiance, and a 40% reduction in the range of irradiance values, thus indicating a significant shift in irradiance distribution patterns. This research aims to inform stakeholders about accurate use of TMY datasets in potential decision-making. These findings underscore the necessity of creating a typical dataset by using the time series of POA irradiance, which represents the orientation in which PV panels will be deployed.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.343-366
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• 1988

Craniofacial complex is influenced by numerical skeletal elements. Though the analysis of growth change has been done by various analytical methods, it was dependent on any method of registration and superimposition, based on reference plane and reference point. However, the craniofacial growth is composed of a number of local growth elements. Therefore, it will be necessary to use a clinically useful method for estimating craniofacial skeletal growth independently. The author analysed longitudinal cephalometric roentgenogram of 15 Korean males and 15 Korean females aged from 6 to 12 years by the finite element method and results were as follows : 1. The finite element method for craniofacial skeletal complex and soft tissue made it possible to analyze the independent local growth. 2. Regression equations from the value of each strain will make it possible to predict the craniofacial growth. 3. The growth of anterior cranial base was different from that of other facial bone. 4. The growth of posterior cranial base influenced the growth of upper pharyngeal region, midfacial region, maxilla and posterior region of mandible. 5. The growth of maxillary complex was vertical rather than horizontal. 6. The growth direction of ramus, mandibular body, alveolar bone was various. 7. The relation between hard tissue and soft tissue by finite element method was variant.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.11 no.1
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• pp.75-78
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• 1981

The diagnostic value of a intra oral film is related to projecting technic and interpretation. The intra-oral film is a single plane representation of a three dimensional object, therefore superimposition is inevitablly present. The purpose of this article is to show how foreign objects in the jaw may be localized. The author used double exposure technics, that are changed angulation of vertical or horizontal to one film. The obtained results are as fallow: 1. In the upper anterior region, the moving distance of the labially impacted reference object was greater than that of the palatally impacted one. 2. In the upper molar region, the moving distance of the mesiobuccal root apex was the greatest and that of palatal root apex was the shortest. 3. In the lower molar region, the change of the alveolar bone level in the buccal side was greater than that of lingual side.

• Geophysics and Geophysical Exploration
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• v.19 no.1
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• pp.1-10
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• 2016

The hypocenter distribution of microseismic events generated by hydraulic fracturing for shale gas development provides essential information for understanding characteristics of fracture network. In this study, we evaluate how inaccurate velocity models influence the inversion results of two widely used location programs, hypoellipse and hypoDD, which are developed based on an iterative linear inversion. We assume that 98 stations are densely located inside the circle with a radius of 4 km and 5 artificial hypocenter sets (S0 ~ S4) are located from the center of the network to the south with 1 km interval. Each hypocenter set contains 25 events placed on the plane. To quantify accuracies of the inversion results, we defined 6 parameters: difference between average hypocenters of assumed and inverted locations, $d_1$; ratio of assumed and inverted areas estimated by hypocenters, r; difference between dip of the reference plane and the best fitting plane for determined hypocenters, ${\theta}$; difference between strike of the reference plane and the best fitting plane for determined hypocenters, ${\phi}$; root-mean-square distance between hypocenters and the best fitting plane, $d_2$; root-mean-square error in horizontal direction on the best fitting plane, $d_3$. Synthetic travel times are calculated for the reference model having 1D layered structure and the inaccurate velocity model for the inversion is constructed by using normal distribution with standard deviations of 0.1, 0.2, and 0.3 km/s, respectively, with respect to the reference model. The parameters $d_1$, r, ${\theta}$, and $d_2$ show positive correlation with the level of velocity perturbations, but the others are not sensitive to the perturbations except S4, which is located at the outer boundary of the network. In cases of S0, S1, S2, and S3, hypoellipse and hypoDD provide similar results for $d_1$. However, for other parameters, hypoDD shows much better results and errors of locations can be reduced by about several meters regardless of the level of perturbations. In light of the purpose to understand the characteristics of hydraulic fracturing, $1{\sigma}$ error of velocity structure should be under 0.2 km/s in hypoellipse and 0.3 km/s in hypoDD.

• The korean journal of orthodontics
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• v.49 no.1
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• pp.49-58
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• 2019

Objective: The aim of this retrospective study was to evaluate and compare the changes in the pharyngeal airway (PA), maxillary sinus volume, and skeletal parameters after rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy. Methods: The records of 40 patients with skeletal Class III malocclusion due to maxillary retrognathism were collected, and the patients were assigned into two groups. The first group comprised 8 male and 12 female patients (mean age, $10.0{\pm}1.1years$) treated using RME/FM for an average of 10 months. The second group comprised 10 male and 10 female patients (mean age, $9.64{\pm}1.3years$) treated using Alt-RAMEC/FM for an average of 12 months. Cone-beam computed tomography images acquired before (T0) and after treatment (T1) were evaluated. Results: Regarding the skeletal effects, significant differences between the groups were the increase in ANS-HRP (perpendicular distance of ANS to the horizontal reference plane, 0.99 mm, p <0.05) in the Alt-RAMEC/FM group and the decrease in PP-SN (palatal plane to Sella-Nasion plane, $0.93^{\circ}$, p < 0.05) in the RME/FM group. Maxillary sinus volumes increased significantly in both the groups, and the increase was statistically significantly higher in the Alt-RAMEC/FM group. Although no significant intergroup differences were observed in PA volumes, both lower ($1,011.19mm^3$) and total ($1,601.21mm^3$), PA volume increased significantly in the Alt-RAMEC/FM group. Conclusions: The different expansion devices and protocols used with FM therapy do not seem to affect the forward movement of the maxilla and PA volumes. In contrast, the increase in maxillary sinus volume was greater in the Alt-RAMEC/FM protocol.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.49.1-49.9
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• 2016

Background: The aim of this report is to present a new reference for aesthetic mandible surgery using three-dimensional cone-beam computed tomography-based treatment planning for orthognathic surgery which can be implemented in surgical planning and perioperative procedure. Methods: To make an objective standard for evaluating aesthetic mandibular outline, we make an aesthetic scoring criteria with consideration of asymmetry, broad mandibular border line, and prominent mandibular angle. Two maxillofacial surgeons and two orthodontists rated their aesthetical evaluation from 1 to 5. Experimental group consisting of 47 female and 38 male patients who had rotational orthognathic two-jaw surgery from 2010 to 2011 were chosen according to aesthetic scoring done by two maxillofacial surgeons and two orthodontists. A high aesthetic score (${\geq}16$) means the facial contour is symmetric, with no broad and narrow aesthetic mandible frontal profiles. Control A group consisted of ten female and ten male patients who had no orthognathic surgery experience and low aesthetic score (${\geq}10$). Control B group consisted of ten female and ten male patients who had no orthognathic surgery experience and had anaesthetic mandibular frontal profile and a high aesthetic score (${\geq}16$). The three-dimensional image of the patient was taken from dental cone-beam CT (DCT) scanning (experimental group and control A group: 6 months DCT after surgery, control B group: 1st visit DCT). Each DCT was reformatted to reorient the 3D image using 3D analyzing program (OnDemand3D, cybermed Inc, CA, USA). After selection of 12 landmarks and the construction of reoriented horizontal, vertical, and coronal reference lines, 15 measurements were taken in 3D analysis of frontal mandibular morphology. Afterwards, horizontal and vertical linear measurements and angular measurements, linear ratio were obtained. Results: Mean $Go^{\prime}_{Rt}-Me^{\prime}-Go^{\prime}_{Lt}$ angular measurement was $100.74{\pm}2.14$ in female patients and $105.37{\pm}3.62$ in male patients. These showed significant difference with control A group in both genders. Ratio of $Go^{\prime}_{Rt}-Go^{\prime}_{Lt}-Me^{\prime}$ length to some linear measurements (ratio of $Me^{\prime}-Cd^{\prime}_{Rt}Cd^{\prime}_{Lt}$ to $Me^{\prime}-Go^{\prime}_{Rt}Go^{\prime}_{Lt}$, ratio of $Me^{\prime}-Go^{\prime}$ to $Me^{\prime}-Go^{\prime}_{Rt}Go^{\prime}_{Lt}$, ratio of $Go^{\prime}_{Rt}-Go^{\prime}_{Lt}$ to $Me^{\prime}-Go^{\prime}_{Rt}Go^{\prime}_{Lt}$) showed significant difference with control A group in both genders. Conclusion: This study was intended to find some standard measurement of mandible frontal view in 3D analysis of aesthetic patient. So, these potential measurement value may be helpful for orthognathic treatment planning to have more aesthetic and perspective outcomes.