Face Width Research Articles

The application of basic SMAS rhytidectomy and comprehensive SMAS rhytidectomy.

Rhytidectomy has made great progress in the past 50 years, especially after the proposition of the concept of superficial musculoaponeurotic system (SMAS). Our previous research had classified SMAS rhytidectomy into basic SMAS rhytidectomy (B-SMAS) and comprehensive SMAS rhytidectomy (C-SMAS) according to whether the treatment of SMAS aponeurosis is combined with retaining ligament, fat pad, mimetic muscles, etc. The purpose of this paper is to compare the outcomes of the 2 methods. Through multicenter collaborative research, 21 cases of B-SMAS and 18 cases of C-SMAS were collected. Photographs were taken pre- and post-operation for each patient, and the facial width of the lateral canthus level (upper face), the alar base level (middle face), and the oral commissure level (lower face) were measured. We compared the statistics of upper, middle, and lower face pre- and post-B-SMAS and C-SMAS to assess the ramifications of each operation. We used preoperative measurements minus corresponding postoperative measurements of specific operation to assess which position would acquire superior improvements. We also recruited 3 professional plastic clinicians to rate the ramifications of specific positions and approaches after pre- and post-photo comparing. Through comprehensive analyzing, we compared the improvements between B-SMAS and C-SMAS to assess which method is more beneficial concerning facial rejuvenation. Both B-SMAS and C-SMAS would acquire optimal changing concerning facial width in middle and lower face after operation (P < .05). Two methods all harvested better width changing effects in middle and lower face than upper face (P < .05). However, C-SMAS acquired better effects in middle and lower face than B-SMAS (P < .05). Both B-SMAS and C-SMAS are beneficial to facial rejuvenation. The effects in middle and lower face are better than upper face. In addition, C-SMAS may be more effective than B-SMAS.

The Periarticular Pelvic Clamp: An Indispensable Aid to Assist in the Narrowing of Facial Width in Mandibular Trauma.

Symphyseal fractures of the mandible with concomitant bilateral condylar fractures can often be a particularly challenging fracture pattern for the facial surgeon. Improper reduction of these fractures may lead to facial widening that proves difficult to correct secondarily. Here the authors describe a method to prevent this unwanted facial widening with the use of an orthopedic periarticular reduction clamp. This method allows for not only increased ease of reduction but also reduces the burden of assistance in manual reduction of the fracture.

Comparisons of the Clinical Outcomes of Mandible Contouring Surgery With or Without the Use of Intraoral Drains.

Mandible contouring surgery is a common cosmetic procedure aimed at reducing the width of the lower face or correcting chin-related issues by contouring the mandible. Typically, an intraoral drain is placed during procedures involving the reduction of the mandible angle portion to mitigate seroma or hematoma formation. Despite this standard practice, anecdotal evidence suggests that the omission of drains does not significantly impact complication rates or surgical outcomes. A retrospective study was conducted to compare surgical outcomes and complication rates between patients who received intraoral drains (n = 338) and those who did not (n = 132) during mandible contouring surgery. The primary outcomes measured included the incidence of seroma, hematoma, and infection by counting the number of post-operative interventions required to address these complications. Statistical analysis was performed using chi-square tests for categorical variables. A p-value of < 0.05 was considered statistically significant. The incidence of post-operative surgical interventions for bleeding control or hematoma evacuation in the drain group was 0.59% compared to 0% in the no-drain group (p = 0.922). Minimally invasive interventions were required in 2.37% of patients with drains and 3.03% without drains (p = 0.933). Infection rates were 1.18% in the drain group versus 0.76% in the no-drain group (p = 1.0). The study demonstrates no statistically significant difference in complication rates between mandible contouring surgeries performed with or without intraoral drains. These findings suggest that the routine use of drains may be unnecessary, potentially simplifying post-operative care and reducing patient discomfort. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Simulation Research on the Control Method of Bow-Collapse in Gear Cold Roll-Beating

Bow-collapse is a type of geometric defect in the gear cold roll-beating process. In order to effectively control bow-collapse and improve material utilization, this paper calculates the cross-section radius of the blank according to the volume invariance principle of metal plastic deformation, and then performs FE simulation of the cold roll-beating process by using the cyclic beating of adjacent tooth spaces and intermittent blank feeding method. The flow state of metal particles is investigated, revealing that the movement of metal particles along the axial direction of the blank is the main reason for the formation of bow-collapse. This paper proposes a method to correct the cross-section radius of the blank and thus control for bow-collapse, where the loss coefficient K characterizes the state of metal particle loss in an infinitesimal thickness region on the cross-section. The analytical equation for calculating the corrected value of the cross-section radius is derived, and the corrected value is calculated. Conducted on the modified blank, cold roll-beating FE simulation results show that bow-collapse is effectively controlled, and the loss coefficient K correctly reflects the loss state of metal particles on the cross-section. The simulation results also show that after cold roll-beating, the gear teeth with standard face width and tooth depth can be obtained after two turning end faces and turning tip circle processes. The bow-collapse control method proposed in this paper effectively improves material utilization.

Effects of Tool Shape on Facial Contour Reduction in Middle-aged Women in Their 50s and 60s

Purpose: This study aimed to evaluate the effect of tool-based facial care on face size reduction in middle-aged women and to analyze the differences in effectiveness by tool form.Methods: The study was conducted with 14 middle-aged women in their 50s and 60s who volunteered to participate at a P aesthetic shop in Gangnam-gu, Seoul. The participants were divided into three groups: Group A (11 participants) received treatment with a meridian-scraping-shaped tool, Group B (4 participants) received treatment with a plain tool, and Group C (3 participants) was untreated. Group A underwent treatment twice a week for a total of six sessions with the meridian-scraping-shaped tool. After a year, some participants from Group A were reassigned to Group B for further care with the plain tool. Face sizes were compared over time by measuring 14 variables, including length, width, and jawline length. Data were analyzed using Kruskal–Wallis and Friedman tests.Results: In Group A, there was a significant reduction in most facial areas, particularly in face width and jaw width (p&lt;0.001). In contrast, Group B showed significant reductions in only some areas, while no changes were observed in the control group. This study found that the meridian-scraping-shaped tool was more effective in reducing facial contours than the plain tool.Conclusion: This study demonstrated that the meridian-scraping-shaped tool, which applies the leverage principle, was more effective in reducing facial contours in middle-aged women compared to the plain tool. The shape of the tool has a critical impact on treatment outcomes.

Creative puppet therapy reduces hallucinations in patients diagnosed with schizophrenia: Preliminary findings

Anomalous experiences and hallucinations characterize schizophrenia. This study aimed at determining the efficacy of creative puppet therapy (CPT; creation of a puppet with malleable DAS) to reduce severe anomalous experiences and hallucinations among patients diagnosed with schizophrenia. Double-blinded, controlled trials were performed on a convenience sample of 24 patients from a mental health center. The intervention group of 12 patients (who created puppets) and the pseudo-treatment group of 12 patients (who were involved in outdoor leisure trips) were compared to the control group of 12 control participants (who created puppets). Cardiff Anomalous Perceptions Scale (CAPS) assessed hallucinations; Emotional Expression Inventory (EEXI) assessed the emotional expression of one's own puppet. Puppet facial features were measured. Results showed that CPT effectively reduced (d = –4.00) hallucination frequency in patients. Hallucination reduction occurred across all sensory modalities, but touch and bodily interoception. Exteroceptive vs. interoceptive hallucinations was the most valuable classification in patients. Compared to controls, puppets created by patients expressed more negative emotions and had larger eye diameters, shorter noses, and larger whole face width. Eye diameter was correlated with fear, sadness, anger, and disgust, and whole face width with boredom. Fragmented-self integration of schizophrenia through CPT treatment might exploit aggregative dominance of the patient's own body.

A clinical prospective study on the surgical management of zygomatico-maxillary complex fractures using two-point fixation

The ZMC fractures are one of the most frequently occurring maxillofacial injuries due to its prominence and facial contour. The ZMC forms a principle buttress of face and helps transmit occlusal forces to skull base. Fracture of zygomatic bone leads aesthetic and functional deformity. Restoration to premorbid condition is most predictable by ORIF. In this study was to evaluate efficacy of two-point internal fixation using conventional miniplates and screws for ZMC fractures. 35 patients with established unilateral isolated ZMC fractures were operated using two-point fixation method i.e. the maxillary buttress and the fronto-zygomatic suture, followed up for 3 months. Patients were assessed clinically and radiographically at different follow up intervals. Charts of patients were reviewed for age, gender, etiology, malar height analysis and vertical dystopia. 35 patients in this study, underwent ORIF under GA with two-point fixation. Preoperatively, mean malar height of the patients recorded was 66.55 ± 3.02. There was a significant increase in malar height postoperatively (P &amp;#60; 0.0001). 70.24 ± 2.05, at 1st week, and 69.87 ± 1.98. in 3rd and 6th weeks. Preoperatively, mean vertical dystopia of patients was 2.24 ± 0.71. Postoperative resolution of vertical dystopia was statistically significant (P&amp;#60;0.0001), with value of 0.52 ± 0.52.Integrity of ZMC is important in maintenance of normal facial width and prominence of cheek. Two‑point fixation shows satisfactory results functionally, esthetically and also provides additional advantage by eliminating another surgical site. Thus we conclude that our study provides a basis for further research.

Polymer gear failure prediction: A regression-Based approach using FEA and photoelasticity technique

The research aims to develop a model to predict the maximum contact stress depth, which will be correlated with polymer gear failures such as wear and rapid thermal deformation. A thorough 3D Finite Element Analysis (FEA) was performed for different gear parameters (varying module, number of teeth, and face width) in different combinations (Polymer – Polymer, Steel – Polymer, and Polymer – Steel). The simulation results showed that the contact stress depth increases with respect to the module and number of teeth; meanwhile, very negligible variations were found along the face width. Also, the findings indicate that the contact stress depth varied in the following descending combinations of gear pair: Polymer – Polymer, Steel – Polymer, and Polymer – Steel. The 3D FEA contact stress patterns were validated experimentally by utilizing the in-house developed photoelasticity test rig. The data obtained from the simulation results were used to develop regression models (Linear regression and Random Forest regressor) for estimating the maximum contact stress depth. A feature importance study was done using the mean reduction of the Gini index or impurities in random forest. It was found that torque applied and contact width of the gear pair were significantly influenced by the contact stress depth. Finally, an equation was developed correlating torque and contact width to predict the depth occurrence of maximum contact stress through which the failure mode of the polymer gear could be predicted.

Craniometric determinants of the fitted filtration efficiency of disposable masks.

Exposure to harmful aerosols is of increasing public health concern due to the SARS-CoV-2 pandemic and wildland fires. These events have prompted risk reduction behaviors, notably the use of disposable respiratory protection. This project investigated whether craniofacial morphology impacts the efficiency of disposable masks (N95, KN95, surgical masks, KF94) most often worn by the public to protect against toxic and infectious aerosols. This project was registered with ClinicaltTrials.gov (NCT05388201; registration May 18, 2022). One-hundred participants (50 men, 50 women) visited the Environmental Protection Agency's Human Studies Facility in Chapel Hill, NC between 2022-2023. Craniometrics and 3D scans were used to separate participants into four clusters. Boosting and elastic net regression yielded five measurements (bizygomatic breadth, nose length, bizygomatic nasal arc, neck circumference, ear breadth) that were the best predictors of filtration efficiency based on overall model fit. Fitted filtration efficiency was quantified for each mask at baseline and when tightened using an ear-loop clip. The mean unmodified mask performance ranged from 55.3% (15.7%) in the large KF94 to 69.5% (12.3%) in the KN95. Modified performance ranged from 66.3% (9.4%) in the surgical to 80.7% (12.0%) in the KN95. Clusters with larger face width and neck circumference had higher unmodified mask efficiency. Larger nose gap area and nose length decreased modified mask performance. We identify face width, nose size, nose shape, neck circumference, and ear breadth as specific features that modulate disposable mask fit in both unmodified and modified conditions. This information can optimize guidance on respiratory protection afforded by disposable ear-loop masks.

The Design and Analysis of the Helical Gear in the Car Gear Box for the Slag Port Transfer

The design and analysis of helical gears with involutes profiles is the primary focus of this study. The most widely utilized gearing system in use today is the involutes gear profile. Power and torque are typically transmitted through them. When compared to other forms of transmission, the efficiency of power transmission via gears is extremely high. Bending and contact stress are the main causes of gear tooth failure. The current study examines helical gear, which has to do with slag transfer in the steel production sector. The most affected stress concentrated location of any set of gears in the slag port transfer car (SPTC) gear box is identified by examining the contact stresses for the current design set of gears. The high stress concentration gear set was redesigned with a constant (45mm) face width at various Helix angles (14, 15, 16, 17, 19^, 20 ̊, 25^, and 30 ̊) and a constant pressure angle (20). To calculate the contact stresses between two gears that are mating. The robust and cutting-edge solid modeling program AUTODESK FUSION 360 creates a three-dimensional solid model. The ANSYS Workbench module was utilized to do the numerical analysis. The outcomes of the workbench module for ANSYS. The current study is helpful in quantifying the previously mentioned factors, which aids in the safe and effective design of the helical gear in the SPTC Gearbox.

Research on the Development Height Prediction Model of Water-Conduction Fracture Zones under Conditions of Extremely Thin Coal Seam Mining

Addressing the difficult problem of predicting the height of water-conducting fracture zones in shallow and thin coal seams, a prediction model of water-conduction fracture zones based on a backpropagation (BP) neural network was developed by integrating theoretical analysis, field measurements, and algorithmic advancements. Firstly, through overburden migration analysis and correlation tests, the height index system of the water-conducting fracture zone was determined. This system includes mining height, buried depth, dip angle, working face width, and overburden rock lithology, with five groups of characteristic parameters. Then, 35 pairs of minefield-measured data were collected to establish the measured height data set of the water-conducting fracture zone. Secondly, a BP neural network prediction model and a traditional support vector regression (SVR) prediction model were constructed based on a Pytorch framework, and the models were trained and tested by selecting data sets. Thirdly, the optimal prediction model was determined by comparing the model with the empirical model and multiple regression model of mining regulations for coal pillar maintenance and pressure in buildings, water bodies, railways, and main shafts. Finally, a typical mine was selected for application to verify the suitability of the optimal model. The results show that: (1) the predicted value of the neural network model is consistent with the change trend of the measured value, which accords with the theoretical law; (2) compared with traditional forecasting methods, the error of the BP neural network prediction model is stable and the prediction effect is the best; (3) dropout can effectively mitigate mitigation training overfitting, achieve regularization, and improve prediction accuracy; (4) the field application further verified that the BP neural network model is the best for predicting the height of water-conducting fracture zones of extremely thin coal seams, and the research results can provide technical guidance for similar fragile coal seams.

The Relationship between the Length/Width of the Face and the Length/Width of the Crown of the Permanent Upper Central Incisors.

Background: The face, with its attractiveness, is positively connected with self-esteem and interpersonal relationships, and the maxillary central incisors are the most noticeable teeth and crucial for smile aesthetics. The aim of this study is to examine facial and permanent upper central incisors' clinical crown dimensions and their correlations to establish whether there is a relationship between the length/width of the face and the length/width of the clinical crown of the permanent upper central incisors. Methods: This study included 100 subjects (43 males and 57 females) with a mean age of 17.5 ± 3.4 years before orthodontic treatment. Facial length and width were measured using a cephalometer by the same orthodontist and the upper central incisors' clinical crown lengths and widths were measured using a sliding calliper by the same dental student. Data were analysed using SPSS version 29.0, presenting descriptive statistics for age, facial and upper central incisor crown dimensions, and indices. Pearson's correlation coefficient assessed the relationship between facial features and the upper central incisors' crown. The significance level was p ≤ 0.05. Results: Males exhibit a slightly higher mean value of the face length (11.6 ± 0.8 cm) compared to females' face length (11.2 ± 1.1 cm) and a statistically significant (p < 0.05) higher mean value of the face width (11.7 ± 0.8 cm) compared to females (11.1 ± 0.6 cm). The facial index shows no statistically significant gender difference (males: 99.1 ± 8.4; females: 101.2 ± 11.9, p > 0.05). The upper central incisor crown dimensions are without statistically significant differences between gender and tooth side: males have mean value clinical crown lengths of 10.2 ± 1.1 mm (left) and 10.1 mm ± 1.2 (right) while females have 9.9 ± 1.0 mm (left) and 9.8 ± 0.7 mm (right). Clinical crown widths are also comparable (males: left 9.0 ± 0.7, right 8.9 ± 0.6 and females: left 8.8 ± 0.7, right 8.8 ± 0.7), with no statistically significant differences observed. The tooth index shows no statistically significant difference but there is a statistically significant (p < 0.05) correlation between the facial index and tooth index. Conclusions: Knowledge of the presented data is important for diagnosis and treatment planning and may be useful for restorative dentists, orthodontists, prosthodontists, and maxillofacial surgeons to achieve an aesthetic result. Clinically, our study supports the development of more personalized treatment plans.

A Study on the Aesthetic Parameters and Proportions of the External Contour for Minimally Invasive Facial Injection.

The aim of this study was to further guide the diagnosis and treatment programs for clinical facial contouring with injectable fillers by studying the facial contour parameters and proportion preferences consistent with Asian aesthetics. A total of 89 subjects (42 males and 47 females aged 20-60 years) who met the inclusion criteria were enrolled in this study. The subjects were grouped by age, sex, and external contour attractiveness score, and the external contour aesthetic parameters and proportions of the subjects in different groups were measured and analysed. The upper facial breadth and lower facial breadth decreased with age, with significant differences between the 50-60-year age group and other age groups (P<0.01). The nasomental angle showed a decreasing trend with age, with significant differences between the 40-49-year age group and the 20-29-year and 30-39-year age groups (P<0.05). Males and females were significantly different in calva height, total head height, lower facial height, and calva height to total head height ratio (P<0.05). With increasing age, the external contour attractiveness scores of males and females both showed decreasing trends, with significant differences between the 50-60-year age group and other age groups (P<0.05). The calva height and the cranioauricular angle have a significant impact on external contour attractiveness. In general, temporal depression, cheek sagging, lateral cheek depression, and an ill-defined mandibular border will occur due to ageing, collagen loss, ligament laxity and sagging, and soft tissue atrophy and sagging, reducing the attractiveness of the external contour. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of Skull Morphometric Characteristics of Simmental and Holstein Cattle Breeds.

This study aimed to reveal the morphological characteristics of pure Holstein and Simmental skulls and to obtain reference values for morphometric analysis. Moreover, 54 skulls from 12- to 14-month-old male Holstein (n = 25) and Simmental (n = 29) cattle were collected from Turkey's Southeastern Anatolia Region between 2023 and 2024. Linear measurements indicated that Holsteins had longer skulls compared to Simmentals. Holsteins exhibited significantly higher values for the greatest length of nasals and the shortest skull length. The facial breadth was wider in Holsteins and statistically distinctive between the breeds. Holsteins had a more oval orbital bony roof, while Simmentals exhibited a wider orbital structure. The orbital index was higher in Holsteins, distinguishing between the two breeds. It was observed that Simmental cattle had a wider occipital region. This difference is likely due to the larger lateral appearance of the Simmental skull, which has more body weight and provides a larger surface area for muscle attachment. These differences not only aid in breed identification but also offer insights into the functional adaptations of each breed. Future research should explore the genetic and environmental factors contributing to these morphological traits, further enriching our knowledge of cattle morphology and its implications for breeding and conservation efforts.

Prediction of the maximum tooth root stress for fatigue analysis of highly crowned spherical gear couplings working at high misaligned conditions

Spherical gear couplings efficiently transfer power between highly misaligned rotating shafts, featuring high longitudinal crowning in their design. At high misalignment angles, the contact point shifts across the face width, reducing the number of teeth in contact and increasing the risk of tooth root fatigue failure.While gear coupling fatigue sizing standards typically address misalignment angles above one degree as special cases, many applications involve misalignment angles exceeding 3°. This paper proposes a surrogate modeling approach to predict maximum tooth root stress for fatigue analysis of spherical gear couplings operating under misaligned conditions. Results indicate that this cannot be predicted in an independent manner from the number of teeth in contact or the effective face width. Consequently, demonstrates that using a single coefficient to account for the effect of the misalignment on load distribution yields optimal results. This research validates the suitability of the presented methodology for predicting tooth root stresses in spherical gear couplings prone to tooth root fatigue failure under high misalignment conditions with a mean error of 0.4%, while it serves as a valuable fast tool for engineers during the design phase.

Treatment of myofascial pain and dysfunction using botulinum toxin A: a prospective study

Abstract Purpose We prospectively assessed the effects of botulinum toxin type-A (BTX-A) on primary and secondary outcomes in a population of refractory myofascial pain and dysfunction patients when conservative management had proven ineffective. Methods In this study, 26 patients with masticatory myofascial pain, who were refractory to conservative management, were enrolled prospectively to evaluate responses following the injection of botulinum toxin-A (BTX-A). Masseter muscles were injected with 30 units BTX-A and 20 units into the temporalis muscles. Pain, tenderness to palpation, and oral function were evaluated subjectively using a visual analog scale (VAS). Objective outcomes of maximal mouth opening (MMO) and reduction in total facial width after injection with BTX-A were measured. Participants were reassessed at 1-week, 1, 3, and 6-month intervals. A linear mixed-effect model was employed to assess the level of correlation (dependence) among different outcomes. Results Administration of BTX-A had a significant strong positive correlation with the reduction of pain (Phi = 0.641, P &lt; 0.0005); significant strong positive correlation with increase in oral function (Phi = 0.738, P &lt; 0.0015); significant strong positive correlation with increase in maximal mouth opening (Phi = 0.645, P &lt; 0.0085); significant strong positive correlation with tenderness to palpation (Phi = 0.510, P &lt; 0.0011); and significant strong positive correlation with reduction in facial width (Phi = 0.565, P &lt; 0.0001). Conclusion The results from this study demonstrate that BTX-A administration may provide a safe and effective means to treat myofascial pain from hyperfunctioning masticatory muscles. It is not recommended to replace first-line treatment but may provide relief from chronic facial pain if properly administered in patients where standard conservative management has been unsuccessful.

Solving a Multi-Objective Optimization Problem of a Two-Stage Helical Gearbox with Second-Stage Double Gear Sets Using the MAIRCA Method

This paper provides a novel application of the multi-criteria decision-making (MCDM) method to the multi-objective optimization problem (MOOP) of creating a two-stage helical gearbox (TSHG) with second-stage double gear sets (SDGSs). The aim of the study is to determine the optimum major design components for enhancing the gearbox efficiency while reducing the gearbox volume. In this work, three primary design parameters are chosen to accomplish this: the gear ratio of the first stage and the coefficients of the wheel face width (CWFW) of the first and second stages. Additionally, the study is conducted with two distinct objectives in mind: the lowest gearbox volume and the maximum gearbox efficiency. Moreover, phase 1 and phase 2, respectively, are the two stages of the MOOP. Phase 2 handles the MOOP to identify the ideal primary design factors as well as the single-objective optimization problem to minimize the difference between the variable levels. Additionally, the Multi-Attributive Ideal–Real Comparative Analysis (MAIRCA) approach is selected to deal with the MOOP. The results of the study are utilized to determine the ideal values for three crucial design parameters in order to create a TSHG with SDGSs.

Three-Dimensional Anthropometric Facial Analysis and Fitting Discrepancies Between Stereophotogrammetry and CT.

The reliability and repeatability of stereophotogrammetry and CT in 3-dimensional anthropometric facial analysis were investigated in this study, which also explored the clinical application of supine CT. In this study, 3D CT and 3dMD stereophotogrammetry were used on 20 healthy volunteers. The fitting distance between stereophotogrammetry and CT scans at landmark points was measured, along with facial feature measurements (Al-Al) face width (Go-Go, Zy-Zy, Ex-Ex), and hemi-face height (Sn-Gn). The intraclass correlation coefficient (ICC) was employed to assess interrater agreement and to verify the reliability of the measurement methods. Paired t -analysis was utilized for analyzing intramethod displacement. The alare, nasion, and pronasale points were found to be minimally influenced by different positions and are more recommended as landmark points for registration. CT demonstrated good interrater reliability on all indicators. In stereophotogrammetry, measurements for Go-Go and Zy-Zy displayed an interclass correlation coefficient (ICC) of less than 0.75. Significant differences between the 2 methods were observed for En-En, Ex-Ex, and Go-Go ( P < 0.05). Specifically, CT analysis for Go-Go showed a measurement 2.34 mm larger than that obtained with the 3dMD method. Both CT and stereophotogrammetry were found to be reliable methods for evaluating facial soft tissue. It is speculated that Go-Go measurement is primarily influenced by factors such as different positions, facial expressions, and gravity. These variables should be carefully considered during the evaluation of the mandibular angle region.

Multi-Objective Optimization of a Two-Stage Helical Gearbox with Second Stage Double Gear-Sets Using TOPSIS Method

The multi-criteria decision-making (MCDM) method was applied in a novel way in this study to the multi-objective optimization problem (MOOP) of designing a two-stage helical gearbox with double gear-sets in the second stage. Finding the best fundamental components to increase gearbox efficiency and decrease gearbox cross-section area was the aim of this study. Three main design factors were chosen for investigation in this work: the first stage gear ratio and the first and second stage coefficients of wheel face width (CWFW). Phase 1 solves the single-objective optimization problem to reduce the gap between variable levels, and phase 2 solves the MOOP to determine the optimal critical design factors. This additionally splits the MOOP into two phases. Additionally, the TOPSIS method was used as an MCDM approach to address the multi-objective optimization issue, and the entropy approach was used to compute the weight criteria. In this study, gearbox efficiency is calculated by considering power losses during idle motion. The multi-objective optimization of a helical gearbox with second stage double gear-sets is addressed using the TOPSIS technique for the first time.

Multi-Objective Optimization of a Two-Stage Helical Gearbox Using MARCOS Method

In order to address the Multi-Objective Optimization Problem (MOOP) in building a two-stage helical gearbox, this work presents a novel application of the Multi-Criterion Decision-Making (MCDM) method. The aim of the study is to determine the optimal primary design factors that will increase gearbox efficiency while decreasing gearbox volume. Three main design parameters were chosen for assessment in this work: the first stage’s gear ratio, and the first and second stages’ Coefficients of Wheel Face Width (CWFW). In addition, the MOOP is divided into two phases: phase 1 solves the single-objective optimization problem to reduce the gap between variable levels, and phase 2 solves the MOOP to determine the optimal primary design factors. Furthermore, the Entropy approach was picked to compute the weight criteria, and the MARCOS method was chosen as an MCDM method to handle the multi-objective optimization issue. The following are important characteristics of the study: Firstly, the MCDM method (MARCOS technique) was successfully applied to solve a MOOP for the first time. Secondly, this work has looked into power losses during idle motion to calculate the efficiency of a two-stage helical gearbox. The results of the study were used in the design of a two-stage helical gearbox in order to identify the optimal values for three important design parameters.