Orbit Width Research Articles

Toroidal modeling of energetic passing particle drift kinetic effects on tearing mode stability

Drift kinetic effects of the neutral beam injection induced passing energetic particles (EPs) on the linear stability of the n = 1 tearing mode (TM) (with the dominant poloidal harmonic of m = 2) are numerically investigated utilizing the MARS-K code (Liu et al 2008 Phys. Plasmas 15 112503), in a tokamak plasma with finite equilibrium pressure and anisotropic thermal transport. In the low plasma pressure regime, it is found that co- (counter-) passing EPs stabilize (destabilize) the TM, agreeing with previous studies. However, as the plasma pressure increases beyond a critical value, it is found that co-passing EPs also destabilize the mode. An in-depth analysis reveals that the net effect of co-passing EPs is a result of competition between the stabilizing contribution from the non-adiabatic drift kinetic terms and the destabilizing contribution associated with adiabatic terms, with the latter becoming more dominant at higher equilibrium pressure. Non-perturbative magnetohydrodynamic-kinetic hybrid modeling also finds that co- and counter-passing EPs modify the TM eigenfunction differently, with the counter-passing EPs enhancing the sideband harmonics. Furthermore, effects of the plasma resistivity and toroidal rotation, as well as that of the equilibrium distribution of EPs in the particle pitch angle space, are also investigated, showing asymmetric results on the TM stability between the co- and counter-passing EPs. The first order finite orbit width correction is found to be stabilizing with co-passing EPs and destabilizing with counter-passing particles. Finally, drift resonances between passing EPs and the TM induce finite frequency to the mode and generate finite net torques inside the plasma, due to the neoclassical toroidal viscosity and the Reynolds stress associated with 3D perturbations.

Evaluation of changes in orbital volume in adult female patients with maxillary transverse deficiency treated with a maxillary skeletal expander.

The effects of using a maxillary skeletal expander (MSE) on the orbital volume and width between periorbital bones in the treatment of adult female patients with maxillary transverse deficiency (MTD) were evalua⁃ted. A total of 20 adult female patients with MTD with an average age of (22.60±6.29) years were included in the study. The patients were treated with MSE. Cone beam computed tomography was performed before expansion (T0) and no more than 3 weeks after expansion (T1). Orbital volume and periorbital bone width were measured with Mimics 21.0 and analyzed with SPSS 20.0. Paired t-test was performed, and a P value of <0.05 indicated significant difference. After expansion, the orbital volume increased by (346.80±275.31) mm3 (P<0.05). The width between the right and left zygomaticomaxillary sutures increased by (1.69±0.57) mm (P<0.05), and the width between the right and left infraorbital points increased by (1.71±0.70) mm (P<0.05). However, the width between the right and left frontozygomatic sutures increased by (0.15±0.32) mm (P>0.05). Finally, the width between the right and left supraorbital points increased by (0.23±0.52) mm (P>0.05). The maxillary skeletal expander slightly expanded the orbital volume in the adult female patients and increased the lateral widths of the periorbital bones.

Sexing from the orbital measurements using computed tomography images and discriminant function analysis in Turkish population

ABSTRACT The main goal of identification in forensic sciences is to estimate characteristics such as sex, age, stature, and ancestry. One of the regions of the human skeleton that most clearly shows sexual dimorphism is the skull. This study aims to evaluate whether the orbital dimensions could be used for sex estimation using Computed Tomography. We examined the orbital measurements of adult Turkish individuals (300 males and 300 females) aged 21–50. We measured Orbital Width, Orbital Height, Biorbital Breadth, and Interocular Breadth by Computed Tomography. The data of the variables showed a normal distribution; therefore, functions of uni/multivariate variables were obtained using Discriminant Function Analysis. Using Discriminant Function Analysis, a significant difference between men and women was determined with an accuracy of 73%. The orbital measurements of the adult Turkish population showed limited forensic significance for sex estimation. Conversely, their potential for examining the interpopulation and intrapopulation differences have been shown.

Linear hybrid simulations of low-frequency fishbone instability driven by energetic passing particles in tokamak plasmas

A linear simulation study of energetic passing particle-driven low-frequency fishbone instability in tokamak plasmas has been carried out using the global kinetic-MHD (magnetohydrodynamics) hybrid code M3D-K. This work is focused on the interaction of energetic passing beam ions and n = 1 mode with a monotonic safety factor q profile and Specifically, the stability and mode frequency as well as mode structure of the n = 1 mode are calculated for scans of parameter values of beam ion beta, beam ion injection energy, beam ion orbit width, beam ion beta profile, as well as background plasma beta. The excited modes are identified as a low-frequency fishbone with the corresponding resonance of where is the beam ion toroidal transit frequency and is the beam ion poloidal transit frequency. The simulated mode frequency is approximately proportional to the beam ion injection energy and beam ion orbit width. The mode structure is similar to that of internal kink mode. These simulation results are similar to the analytic theory of Yu et al.

Hybrid simulations of beta-induced Alfvén eigenmode with reversed safety factor profile

Based on the experimental parameters in the HL-2A tokamak, hybrid simulations have been carried out to investigate the linear stability and nonlinear dynamics of the beta-induced Alfvén eigenmode (BAE). It is found that the (m/n = 3/2) BAE is excited by co-passing energetic ions with q min = 1.5 in linear simulation, and the mode frequency is consistent with the experimental measurement. The simulation results show that the energetic ions β h, the injection velocity v 0, and orbit width parameter ρ h of energetic ions are important parameters determining the drive of BAE. Furthermore, the effect of q min (with the fixed shape of the q profile) is studied, and it is found that when q min ⩽ 1.5, the excited modes are BAEs, which are located near q = 1.5 rational surfaces; when q min > 1.5, the excited modes are similar to the reversed-shear Alfvén eigenmodes, which are mainly localized around q = q min surfaces. Nonlinear simulation results show that the nonlinear dynamics of BAE are sensitive to the EP drive. For the strongly driven case, firstly, redistribution and transport of energetic ions are trigged by 3/2 BAE, which raised the radial gradient of the distibution function of energetic ions near the q = 2 rational surface, and then an energetic particle mode (EPM) (m/n = 4/2) is driven in the nonlinear phase. Finally, these two instabilities triggered a significant redistribution of energetic ions, which results in the twice-repeated and mostlydownward frequency chirping of 3/2 BAE. For the weakly driven case, there are no 4/2 EPM being driven nor twice-repeated chirping in the nonlinear phase, since the radial gradient near q = 2 rational surface is small and almost unchanged.

Revisiting the improved core confinement simulations for FT‐2 tokamak

AbstractIn the present paper, we revisit observations performed in FT‐2 tokamak from previous works. Improvements of core confinement are observed and believed to be caused by wide orbits going from collisionless to collisional regimes. Similar phenomena can occur whenever gradient lengths are comparable to the orbit widths at the top of the pedestal and the loss cone is continuously and increasingly filled by heated particles, collisions and turbulent effects. The lower hybrid heating operator is introduced into the ELMFIRE code to increase the ion temperature during the simulations while keeping the edge temperature low with logical boundary condition at the limiter. Particular focus is given on how the radial electric field deviates from the neoclassical value while introducing turbulent effects.

Prediction of the energetic particle redistribution by an improved critical gradient model and analysis of the transport threshold

Based on the theory of critical gradient model (CGM) and following the simulation method proposed by Waltz et al. [Nucl. Fusion 55, 123012 (2015)], a combination of TGLFEP and EPtran code is employed to predict the energetic particle (EP) transport induced by Alfvén eigenmodes (AEs). To be consistent with the experiment, recent improvements to the simulation method include consideration of threshold evolution and orbit loss due to finite orbit width. The revised CGM is applied to simulate two DIII-D experimental discharges (#142111 and #153071). It well reproduces the experimental profiles with multiple unstable AEs and large-scale EP transport. Discharge #142111 had previously been simulated using a nonlinear MHD-kinetic code MEGA [Todo et al., Nucl. Fusion 55, 073020 (2015)] with a transport mechanism based on stochasticity induced by overlapping AE. By comparing the simulated EP profiles, we find that the AE transport threshold is approximated by both the MEGA nonlinear stability threshold and the proposed CGM threshold (error &amp;lt;5% for single n and &amp;lt;17% for multiple n simulation). Both of them are larger than the linear stability threshold of the most unstable AE mode by a quantity of the order of the flux needed to sustain EP transport by the background turbulence. We have also applied the improved CGM to simulate the α particle redistribution for a China Fusion Engineering Test Reactor steady state scenario. Because of the clear separation between the AE unstable region and the loss cone, only a moderate α particle loss of ∼9.6% is predicted.

Generation of E × B flow shear by finite orbit width effects from heat sources in tokamaks

We present a possible mechanism for the generation of strong E × B flow shear relevant to internal transport barrier formation in tokamak plasmas. From gyrokinetic calculations, we show that strong E × B flow shear can be generated by finite orbit width (FOW) effects associated with a non-uniform heat source and is sufficient to lead to transport barrier formation in the core region with a moderate power level. Two FOW effects inducing neoclassical polarization are shown to be responsible for this: (1) the radial drift of particle orbit center due to the variation of the heat source within orbit width and (2) the non-uniformly evolved orbit width by the non-uniform heating.

Differences in anthropometric measures of the orbit between Serbian and Roma populations of the Central Serbia

Introduction/Objectives. The shape and size of the orbital cavity are important parameters in planning surgical interventions and have significance in anthropology and forensic medicine. The aim of this study was to determine the morphometric characteristics of orbital cavity in Serbian population and to examine if there are differences in examined parameters between Serbs and the Roma Community of Serbia. Methods. Using computer tomography and subsequent multiplanar reconstruction we analyzed orbits from 76 Serbian and 18 Roma healthy volunteers. There was no significant difference in age between the ethnicities. Results. The height and width of the left orbit and the height of the right orbit were significantly higher in Roma group, whereas the width of the right orbit was not statistically different between ethnicities. Orbital indices, however, for both left and right orbit did not significantly differ between Serbian and Roma examinees. Right orbital volume did not differ between the groups, but left orbits had significantly larger volumes in Roma population. Finally, biorbital and interorbital width were both significantly higher in Roma than in Serbian examinees. We could not show differences between sexes except for the biorbital width, which had lower values in Serbian, but not Roma women than in men. Conclusion. Taken together, our results indicate larger orbits, as well as greater distances between the eyes in Roma than in Serbian examinees.

O vorvaních (Physeter macrocephalus) ve sbírce Národního muzea v Praze (Mammalia: Artiodactyla)

A complete skeleton of the sperm whale (Physeter macrocephalus) from an animal ca. 13–14 m long is here reported as a new acquisition to the collection of mammals of the National Museum in Prague. This large new specimen was transferred to Prague museum from the Zoological museum of Senckenberg Natural History Collection Dresden, Germany, where a space enough was not available in the collection depositary rooms for its storage (the skull was stored outdoors, the rest of the skeleton in a taxidermy workshop). The skeleton originates from a stranded individual of the sperm whale discovered (along with two others) on the North Sea shore at Friedrichskoog (Holstein, Germany) on 15 January 2002. Selected measurements of the skull of this sperm whale are as follows: condylobasal length of skull 418 cm, orbital width of skull 196 cm, basal width of rostrum 144 cm, length of left mandible 374 cm, mandible height at the ramus mandibulae 58 cm. An annotated review of museum specimens of the great whales (= baleen whales and the sperm whale) in collections in the Czech Republic and a detailed description of the sperm whale specimens in the National Museum are added.

Application of Computer-Aided Design and Individualized Templates for Bilateral Zygomaticomaxillary Complex Fractures.

Reduction of the bilateral zygomaticomaxillary complex (ZMC) fracture with individualized templates based on computer- aided surgical simulation system. To evaluate the practicality and accuracy of this approach in the treatment of bilateral ZMC fracture. Sixteen patients with bilateral ZMC fractures were collected to create a study model. The authors reconstruct the ZMC on one side via the three-dimensional (3D) model, and then mirrored to the opposite side. Multiple individualized templates were made based on the 3D model, and used as intraoperative guidance to reduce fractures. After surgery, the facial symmetry and the position of zygoma were observed. The mouth opening, pupil level, and sensation of infraorbital nerve were evaluated. Some mark points on zygoma were measured and the postoperative horizontal asymmetry rate (H) was calculated. Besides, orbital height and width were measured. For all patients, the position of bilateral ZMC was basically restored. The patients with restriction of mouth opening all recovered to normal. The H values were less than 3.0% at all mark points. There was almost no difference in bilateral orbital width and height. Meanwhile, there was no significant difference between the preoperative measurements of the ideal virtual 3D model and the postoperative measurements of patients. The study proves that application of computer-aided design and individualized templates can accurately guide the reduction operation of ZMC fracture, restore the ideal shape of ZMC, and obtain good facial symmetry.

Sheath collapse at critical shallow angle due to kinetic effects

The Debye sheath is known to vanish completely in magnetised plasmas for a sufficiently small electron gyroradius and small angle between the magnetic field and the wall. This angle depends on the current onto the wall. When the Debye sheath vanishes, there is still a potential drop between the wall and the plasma across the magnetic presheath. The magnetic field angle corresponding to the predicted sheath collapse is shown to be much smaller than previous estimates, scaling with the electron-ion mass ratio and not with the square root of the mass ratio. This is shown to be a consequence of the kinetic electron and finite ion orbit width effects, which are not captured by fluid models. The wall potential with respect to the bulk plasma at which the Debye sheath vanishes is calculated. Above this wall potential, it is possible that the Debye sheath will invert.

"Validation of Artificial Intelligence Severity Assessment in Metopic Craniosynostosis".

Several severity metrics have been developed for metopic craniosynostosis, including a recent machine learning-derived algorithm. This study assessed the diagnostic concordance between machine learning and previously published severity indices. Preoperative computed tomography (CT) scans of patients who underwent surgical correction of metopic craniosynostosis were quantitatively analyzed for severity. Each scan was manually measured to derive manual severity scores and also received a scaled metopic severity score (MSS) assigned by the machine learning algorithm. Regression analysis was used to correlate manually captured measurements to MSS. ROC analysis was performed for each severity metric and were compared to how accurately they distinguished cases of metopic synostosis from controls. In total, 194 CT scans were analyzed, 167 with metopic synostosis and 27 controls. The mean scaled MSS for the patients with metopic was 6.18 ± 2.53 compared to 0.60 ± 1.25 for controls. Multivariable regression analyses yielded an R-square of 0.66, with significant manual measurements of endocranial bifrontal angle (EBA) (P = 0.023), posterior angle of the anterior cranial fossa (p < 0.001), temporal depression angle (P = 0.042), age (P < 0.001), biparietal distance (P < 0.001), interdacryon distance (P = 0.033), and orbital width (P < 0.001). ROC analysis demonstrated a high diagnostic value of the MSS (AUC = 0.96, P < 0.001), which was comparable to other validated indices including the adjusted EBA (AUC = 0.98), EBA (AUC = 0.97), and biparietal/bitemporal ratio (AUC = 0.95). The machine learning algorithm offers an objective assessment of morphologic severity that provides a reliable composite impression of severity. The generated score is comparable to other severity indices in ability to distinguish cases of metopic synostosis from controls.

Effects of Spin–Orbit Resonances and Tidal Heating on the Inner Edge of the Habitable Zone

Abstract Much attention has been given to the climate dynamics and habitable boundaries of synchronously rotating planets around low mass stars. However, other rotational states are possible, including spin–orbit resonant configurations, particularly when higher eccentricity orbits can be maintained in a system. Additionally, the oscillating strain as a planet moves from periastron to apoastron results in friction and tidal heating, which can be an important energy source. Here, we simulate the climate of ocean-covered planets near the inner edge of the habitable zone around M to solar stars with the NASA GISS ROCKE-3D general circulation model, and leverage the planetary evolution software package, VPLanet, to calculate tidal heating rates for Earth-sized planets orbiting 2600 and 3000 K stars. This study is the first to use a 3D general circulation model that implements tidal heating to investigate habitability for multiple resonant states. We find that for reference experiments without tidal heating, the resonant state has little impact on the radial position of the inner edge because for a given stellar flux, higher-order states tend to be warmer than synchronous rotators, but for a given temperature, have drier upper atmospheres. However, when strong tidal heating is present, the rotational component implies a strong dependence of habitable conditions on the system evolution and rotational state. Since tidal and stellar heating both decrease rapidly with orbital distance, this results in a compact orbital width separating temperate and uninhabitable climates. We summarize these results and also compare ROCKE-3D to previously published simulations of the inner edge.

Influence of circulating energetic ions on MHD instabilities in negative magnetic shear plasma

The influence of circulating energetic ions (CEIs) on double tearing mode (DTM) is investigated by a global kinetic-MHD hybrid simulation. It is shown that the co-CEIs with a small orbit width have a destabilizing effect on the DTM. As the orbit width increases, this destabilizing effect is reduced. If the orbit width is large enough, the DTM is transformed to single tearing modes due to the co-CEIs, so the mode becomes more stable than the DTM without CEIs. The effect of the counter-CEIs with small orbit width is similar to that of the co-CEIs. For a large orbit width, the counter-CEIs also have a stabilizing effect. If the energetic ion beta is larger than a threshold, an energetic particle driven mode (EPM) is excited due to the resonance between counter-CEIs and the bulk plasma. The effects of energetic ion beta, orbit width and resistivity on this EPM are studied systematically. The onset threshold of EPM depends on the orbit width and resistivity. It decreases with orbit width increasing, while it increases with resistivity increasing. The mode transition from DTM to EPM with energetic ion beta increasing is also found for large orbit width.

Assessment of the Orbital and Auricular Asymmetry in Italian and Sudanese Children: A Three-Dimensional Study

The evaluation of the symmetry of orbital and ear soft tissues is important for aesthetic and reconstructive surgery. However, little information is available for these facial regions, especially in children. We analyzed the orbital and auricular symmetry in 418 Italian and 206 Sudanese subadult males divided into three age groups (8–11, 12–15, and 16–19 years old). Orbital and auricular height and width were measured for calculating fluctuating and directional asymmetry indices. Differences in asymmetry indices according to ethnicity and age group were assessed through the two-way ANOVA test (p &lt; 0.01), while differences in the prevalence of right or left asymmetry according to ethnicity were assessed through the chi-square test. On average, directional asymmetry indices ranged from −2.1% to 1.1%, while fluctuating asymmetry indices ranged between 2.9% and 5.4%, corresponding to a small effect size and to 1.06–2.34 mm actual dimensions. Sudanese subjects showed a greater asymmetry for all the indices except for the fluctuating asymmetry of orbital height (p &lt; 0.01). The directional asymmetry of auricular width increased with age. A prevalent right-side asymmetry was found for all the orbital indices (p &lt; 0.001) in both populations, although significantly more prevalent in Sudanese individuals (over 83% for both measures), while auricular measures showed a prevalent left asymmetry exclusively in the Sudanese but with lower percentages. Aside from the limited effect size, the results proved the ethnic variability of asymmetry of orbital and auricle regions in children and suggest the need to collect more population data.

Morphological and Morphometric Analysis of the Orbital Aperture and Their Correlation With Age and Gender: A Retrospective Digital Radiographic Study.

PurposePrecise knowledge about clinically observed bony orbital aging is needed for surgical planning for acceptable cosmetic results. The effect of age and gender on the facial skeleton and orbital aperture has been appreciated earlier, but its quantification remains ignored. The purpose of this study was to evaluate age- and sex-related changes in the shape of the orbital aperture and construct a reference data set for the aging phenomenon in Indians.MethodsTwo hundred digital radiographs (Water’s/frontal view) of the skull, obtained for various reasons, were evaluated. The radiographs comprised 107 males and 93 females aged between 10 and 60 years (10-59 years). Orbital shape, height/width, and interorbital/biorbital distances were noted, and orbital indices (OIs) were calculated. Orbital parameters thus obtained were compared between right and left sides and males and females. The relation of the parameters with age and gender was analyzed.ResultsFour types of orbits, round (33.5%), elliptical (30.5%), rectangular (27.5%), and square (9.5%), were noted in the study population. The average value of height and width of the right orbit was found to be higher than that of the left (p > 0.05). Male patients had higher (p > 0.05) and wider (p > 0.05) orbits than females. The right OI (81.55 ± 5.30) was higher than the left (80.75 ± 4.80) (p > 0.05). When comparatively evaluated between gender, both orbits were found to be of the microseme type with a mere difference (p > 0.05). The average interorbital/biorbital distance was 1.27 ± 2.11 and 9.78 ± 4.40 cm, respectively, without any gender difference. No significant relation was found between the age change and the parameters defined (p > 0.05), except in one age group (10-19 years).ConclusionsOrbital dimensions showed no association with age and gender except in one age group (10-19 years); a pubertal growth spurt in females might be causing this phenomenon. The morphometric data may be useful in forensic anthropology and better planning for reconstructive surgeries in the orbito-maxillary region.

Improved neoclassical plasma confinement and turbulence suppression in a magnetic well in tokamak reactors

It has been known that the width of the trapped particles, i.e. bananas, is reduced or squeezed in a magnetic well in tokamaks. The magnetic squeezing factor S B depends on the energy and pitch angle of the particles. When ρ p/a ∼ 1, S B becomes appreciably larger than unity; it can be of the order of 2 for a parabolic well with B −1 d2 B/dr 2 ∼ 2a −2. Here, ρ p is the poloidal gyro-radius, B is the magnetic field strength, r is the local minor radius, and a is the minor radius. However, the real orbit width measured in terms of the poloidal magnetic flux is still less than a because of the magnetic squeezing; for S B = 2, it is a 30% reduction. The transport consequences of the squeezed bananas in a magnetic well are calculated by solving the drift kinetic equation utilizing the constants of motion in the large aspect ratio limit. Consequently, neoclassical ion heat conductivity χ h in the reactor relevant collisionality regime (i.e. banana regime) is reduced by a factor of ; for S B = 2, it is almost a factor of three reduction for the same temperature. The ion temperature scaling of χ h improves from the conventional, and weakly favorable scaling to the strongly favorable scaling for high temperature fusion grade tokamak plasmas; the scaling however does not take the temperature dependence of the magnetic well itself into account. Here, T i is the ion temperature. In addition, it is shown that plasma turbulence is suppressed in a magnetic well using the reduced decorrelation time argument and anomalous plasma confinement is improved. The combined improvements result in a favorable temperature scaling in the ion energy confinement time, and make burning aneutronic fuels feasible. The implications on a tokamak with a magnetic well as a fusion reactor are discussed.

Variations in Facial Anthropometric Measurements among Major Ethnic Groups in Nigeria: A 3-Dimentional Stereophotogrammetry Analysis

Objectives: The aim of the study is to highlight variations in facial anthropometric measurements among the major ethnic groups in Nigeria using 3D photogrammetry. Materials and Methods: This study was conducted in Lagos, Nigeria. Acquisition of 3D facial photographs was done using a Vectra H1 portable 3D photogrammetry imaging system. Descriptive analysis of collected data was done and a test of associations performed using independent samples t-test. The level of significance was set at &lt;.05. Results: The total number of participants in this study was 503. The study population was made up of 302 (60%) males and 201 (40%) females. Mean upper facial height among Yoruba, Igbo, Hausa, and other ethnic groups were 68.93 ± 5.85, 70.18 ± 5.99, 63.79 ± 4.80, and 69.29 ± 5.95 mm respectively, while mean interpupillary distances were 66.99 ± 3.70, 67.34 ± 3.56, 66.73 ± 3.80, and 67.09 ± 3.72 mm respectively. A Tukey posthoc test revealed significant pairwise differences for upper facial height between the Yoruba and Hausa population with a mean difference of 5.15 mm ( P &lt; .001, 95% CI 2.94-7.35) ( P &lt; .001, 95% CI 2.94-7.35), and Hausa and Igbo population with a mean difference of 6.39 mm ( P &lt; .001, 95% CI 3.75-9.03). Multivariate regression analysis confirmed the presence of significant inter-ethnic differences between Hausa ethnic group and the Yoruba ethnic group for midfacial height ( P &lt; .001), upper lip height ( P = .004), lower lip height ( P = .003), total face height ( P = .010), and orbital fissure width ( P &lt; .001). Conclusion: The result of this study shows that distinct difference does exist in the facial anthropological measurements between the ethnicities included in this study especially in vertical facial measurements.

Objective Analysis of Fronto-Orbital Dysmorphology in Unilateral Coronal Craniosynostosis.

Correction (and over-correction) of asymmetries of the orbital shape and brow position in unilateral coronal craniosynostosis (UCS) is critical to successful fronto-orbital advancement. Here we quantify and three-dimensionally assess fronto-orbital irregularities in UCS patients compared to controls.Twenty-three patients with UCS evaluated at the Children's Hospital of Pittsburgh between 2006 and 2016 were age and gender-matched to controls. Computed tomography scans were reconstructed and evaluated for orbital metrics. A three-dimensional heat map of orbital regions was generated and evaluated for shape differences.Brow protrusion of the orbit ipsilateral to the synostotic suture did not differ significantly from healthy controls. Orbital height was significantly increased while orbital width was decreased on the UCS ipsilateral side compared to the contralateral side and controls. The ipsilateral cornea was overprojected relative to the brow and the infraorbital rim, but similar to controls relative to the lateral rim. The contralateral orbit had increased brow protrusion with decreased orbital height. The cornea was underprojected relative to the brow, but overprojected relative to the lateral orbital rim and similar to controls at the infraorbital rim. Three-dimensional comparison demonstrated significant overprojection of the contralateral brow, with some more mild and inconsistent underprojection of the lateral aspect of the ipsilateral brow.Key orbital and brow differences exist between the affected and unaffected sides in UCS. This study provides quantitative data that further characterize the orbital dysmorphology observed in UCS and identifies unique aspects of the diagnosis that should be taken into consideration during surgical planning.