Orbit Circumference Research Articles

Surgical Correction of Orbital Hypertelorism With Absorbable Plate Instead of Frontal and Orbital Bar and Inverted U-Shaped Osteotomy.

The aim of the study is to investigate the effect and feasibility of using absorbable plate instead of frontal and orbital bar and inverted U-shaped osteotomy to correct the widening of orbital distance. The surgical effect and feasibility of using absorbable plate instead of frontal and orbital bridge plus inverted U-osteotomy for orbital widening syndrome in seven cases between January 2019 and February 2022 were retrospectively analyzed. First, the surgical procedure for orbital hypertelorism was inverted U-shaped orbital osteotomy, and a frontal bone flap was removed, exposing the superior orbital margin and the orbital circumference, and the orbital bone was directly cut off by inverted U-shaped osteotomy. The widened bone in the middle of the orbit was removed, and a long absorbable plate was used to replace the orbitofrontal bridge. The two sides of the orbit were fixed on the absorbable plate, and the absorbable plate was fixed on the rear skull. The clinical effect of treatment, complications (such as cerebrospinal fluid leakage and infection), safety, and feasibility of surgery were evaluated. Using absorbable plate instead of fronto-orbital bridge achieved the effect of orbitofrontal bridge, without orbital distance widening, cerebrospinal fluid leakage, and intracranial infection. Operating time was reduced. There was no metal fixation, and there was no risk of a second operation. The effect of replacing the frontal-orbital bridge with an absorbable plate and inverted U-shaped osteotomy is positive, the operation time is short, and the orbital distance is clearly improved. This approach can replace the traditional orbital-distance operation, and the incidence of postoperative cerebrospinal fluid leakage and infection is low. Long-term follow-up results are stable.

Development of the Orbit and Eyeball during the Fetal Period

Aim: We aimed to investigate the morphometric development of the orbit and eyeball in the fetal period. Material and Methods: The present study was carried out on 136 fetal eyes (86 males, 50 females) obtained from 68 fetuses aged between 15-40 gestational weeks. In this study, the area, height, width, volume, depth, and circumference parameters of the orbit were measured, while the anteroposterior and transverse diameters, weight and volume parameters of the eyeball were measured. Also, the diameter at the place where the optic nerve enters the eyeball was measured. Results: It was determined that all parameters increased during the trimesters and there was a statistically significant difference between the trimesters in all parameters. There was no statistically significant difference in all parameters in terms of gender. In the comparison of the right and left sides, orbital area (p<0.011), orbital circumference (p<0.048) and orbital width (p<0.048) were higher on the right side. There was no difference between the parties in any of the parameters related to the eyeball (p>0.05). However, the diameter of the optic nerve was higher on the left side (p<0.001). Conclusion: The data we obtained will be very useful in evaluating the pregnancy follow-up by imaging methods such as ultrasonography or magnetic resonance, in the early diagnosis of malformations or diseases, and in planning the treatment.

Rotation of the Ipsilateral Supraorbital Rim Around the Horizontal Axis in Unilateral Coronal Synostosis: A Craniometric Analysis of the Emergence Profile.

Unilateral coronal synostosis (UCS) results in well-defined dysmorphic changes including sphenoid malposition yielding posterior displacement of the supraorbital rim. Although variation in the ipsilateral supraorbital rim emergence profile has been suggested, it has not been previously investigated. The authors sought to characterize the emergence profile of the ipsilateral supraorbital rim in UCS through craniometric analysis. Thirty-five nonsyndromic UCS patients (0-18 months) with CT images obtained before operative intervention and 16 control patients (0-24 months, 32 orbits) were included. Craniometric measurements were performed to quantify the emergence profile of the ipsilateral supraorbital rim and locate the likely apex of rotation. The ipsilateral supraorbital rim was significantly rotated around the horizontal axis when measured in reference to the 0° vertical in UCS versus control patients by an average difference of 7.3° to 11.3° across age groups (P < 0.05). No significant effect modification was detected between age and UCS on ipsilateral supraorbital rim emergence profile (P > 0.05). Additional angles with vertices around the superior orbital circumference were then measured to locate the likely apex of rotation and revealed a significant decrease in the posterior orbital roof to 0° horizontal in UCS patients by an average of 9.3° to 22.1° in children under 1 year old (P < 0.01). Variation in the emergence profile of the ipsilateral supraorbital rim in UCS is quantified, and the apex of this rotation likely lies at the posterior orbital roof. The novel quantification and characterization of this deformity will better direct the operative approach and enable a more accurate correction.

Three-dimensional Coordinate System for Hemifacial Microsomia.

Background:Hemifacial microsomia (HFM) is a congenital disorder characterized by facial asymmetry, but no midline reference has been established for evaluating facial morphology in patients with HFM. The purpose of this study was to develop a 3-dimensional coordinate system unaffected by the deformity of the external acoustic aperture or orbital circumference and to quantitatively evaluate craniofacial morphology in such patients.Methods:We quantitatively evaluated craniofacial morphology using 3-dimensional measurements with the skull base as a reference. Using computed tomography data from 15 patients with HFM and 15 controls, a coordinate system was created for each patient, and left–right differences between measurement points were compared.Results:When mandibular deformity was severe, the deformity of the posterior part of the palatine bone and lateral part of the orbit increased, but this trend was not evident for other measurement points. Thus, craniofacial deformity in HFM was not always related to mandibular deformity. Moreover, no difference was evident in the position of the hypoglossal canal between controls and patients with HFM.Conclusions:Quantitative assessments are possible using the coordinate system devised in this study, irrespective of the severity of HFM. The degree of mandibular deformity detailed in the Pruzansky classification was associated with the superoinferior deformity of the posterior part of the palatine bone and anteroposterior deformity of the lateral part of the orbit.

Оптимизация магнитной структуры источника синхротронного излучения четвертого поколения СКИФ в Новосибирске

We study magnetic lattice and optimize parameters for the fourth generation light source SKIF (Russian acronym of Siberian Circular Photon Source) to be built in Novosibirsk. We consider several lattice cells to achieve both low emittance and large dynamic aperture. The resulting lattice provides the natural emittance of the electron beam of 75 pm for the beam energy of 3 GeV and the orbit circumference of 476 m. Only two families of chromatic sextupoles give the dynamic aperture and energy bandwidth enough for both good beam lifetime and simple effective injection.

Connection between zero chromaticity and long in-plane polarization lifetime in a magnetic storage ring

In this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97−GeV/c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting.16 MoreReceived 23 October 2017DOI:https://doi.org/10.1103/PhysRevAccelBeams.21.024201Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeam diagnosticsBeam polarizationLow-energy multiple-particle dynamicsAccelerators & Beams

A biometric study of the fetal orbit and lens in normal pregnancies

To construct nomograms of the size of the fetal orbit and lens and to evaluate the relationships between the gestational age and the biometry of the fetal orbit and lens. Six hundred two normal pregnant women were evaluated from 15 to 40 weeks of gestation. Fetal orbital and lens measurements were added to routine biometric measurements for normal fetuses. A total of 595 measurements were used for analyses. A strong linear correlation was observed between gestational age and orbital diameter, orbital circumference, and orbital surface. A linear correlation was also found between gestational age and lens diameter, lens circumference, and lens surface. A linear growth function was observed between biparietal diameter and both the orbital diameter and the lens diameter. Orbital and lens measurements provide data that correlate with fetal growth and development. These data may also help detect fetal ocular abnormalities.

Passive Electrostatic Recycling Spectrometer of Desk-Top Size for Charged Particles of Low Kinetic Energy

A passive electrostatic recycling spectrometer for charged particles is described and demonstrated to store electrons with typical kinetic energies of tens of eV. The design of the charged particle optics and the basic operating characteristics of the storage ring are discussed. The storage lifetime achieved is approximately 50 micros, which is target gas pressure limited and corresponds to approximately 200 orbits of the 0.65 m orbital circumference. The storage ring also has controllable energy dispersive elements enabling it to operate as a spectroscopic device.

Guidance of a Roll-Only Camera for Ground Observation in Wind

How a nose-mounted imaging sensor with a single-motion axis in roll can be used for ground observation is demonstrated. Itis shown that point, line, andarea observation areallpossiblein thepresenceofwind.Continuous point observation is possible by the use of an orbital trajectory in conjunction with a lookdown angle of 90 deg. For other lookdown angles the trajectories are spirals. Algorithms are derived for aircraft guidance including the cases of arbitrary lookdown angles and stationary or moving ground points, and the effects are illustrated using a six-degree-of-freedom simulation model. The effects of aircraft attitude, wind estimation, and height errors are discussed. Nomenclature C = orbit circumference c = C=H E = distance east e = E=H g = acceleration due to gravity H = altitude KA = heading control gain N = distance north n = N=H nacc = load factor R = ground range from target to aircraft R0 = perifocus range r = R=H T = orbital period u = inertial velocity vector ur = airspeed

Diurnal deviation of the orbit circumference due to building distortion

Beam position stability was found to be largely affected by the distortion of the storage ring building, especially when the beam emittance was lowered. Building distortion in the horizontal direction was noticed as the diurnal deviation of the orbit circumference. The deviation was measured by reading the amount of rf frequency variation necessary to recover the horizontal central orbit. The deviation of the orbit circumference was interpreted to be induced from the ring floor expansion. Such diurnal expansion of the ring floor was evaluated by using a model simulation that dealt with the distortion of the ring building under thermal stress. To reduce such thermal stress, the rooftop of the building was insulated. The deviation of the ring circumference measured after insulation was reduced to one-half of that measured before. The simulation also gave the same amount of deviations as measured before and after insulation.

The project of using a compact SR source at the Siberian microelectronic center

The project for the x-ray lithography facility using a compact storage ring SIBERIA-AS is considered. The SR source with 600-MeV electron energy and an orbit circumference of about 3 m has an ironless superconducting azimuthally symmetrical magnet. It allows us to install up to 15 SR beam lines. The scope of the project is further development of x-ray lithography, and new technologies in this area for development of scientific research: vacuum ultraviolet spectroscopy, photoinduced etching, photoelectron spectroscopy, and radiometry.

Compact superconducting storage ring with azimuthal symmetry — SR source for technological purposes

The project for a compact storage ring SIBERIA-AS — a synchrotron radiation (SR) source for X-ray lithography with an electron energy of 600 MeV and an orbit circumference of about 3 m — is considered. The major component of the storage ring is a 3.8 T azimuthally symmetrical magnet consisting of annular superconducting coils without utilization of ferromagnetic material. The suggested design has enabled the effect of iron yoke saturation on the magnetic field distribution to be eliminated, and both the weight (about 8 tons) and the overall dimensions (a cylinder of 2 m in diameter and 2 m in height) to be considerably reduced. The basic systems of the storage ring are described and its parameters are reported.

Io's sodium emission cloud

Strong evidence that Io's sodium emission is due to resonant scattering is given by our observations which show a monotonic increase of emission intensity with residual solar intensity. In addition we detected no emission during three eclipse observations of Io. We propose a resonant scattering model with two spacial components comprising an optically thick atmosphere extending 10 3 km above Io's surface surrounded by an optically thin cloud which forms a partial torus around Jupiter. In this model a flux of 10 7 cm −2 sec −1 sodium atoms are sputtered from Io's surface by heavy energetic ions which are accelerated in a plasma sheath around Io. The atoms sputtered from the surface collide with atoms in Io's atmosphere so the equipartition of kinetic energy is established. The total sodium abundance is about 3 × 10 13 cm −2. During Io's day, sodium and other atmospheric constituents are ionized, giving rise to the ionosphere observed by Pioneer 10. Atoms escape by means of Jeans escape from the critical level, which is at the top of the atmosphere and the base of the cloud. We have observed sodium emission 6arcsec (6 Io diameters) above and below Io's orbital plane and 23arcsec toward Jupiter in Io's orbital plane. No emission was detected at maximum elongation 180° from Io. We interpret these results to mean that atoms escaping from Io form a partial torus whose thickness is about 12 arcsec and whose length is at least one-fifth of Io's orbital circumference.

The Dynamics of a Synchrotron with Straight Sections

The equations describing the ``betatron'' and ``synchrotron'' oscillations of a particle being accelerated in a synchrotron having straight sections are obtained. In particular, the relative increase in the ratio of either betatron-oscillation frequency to the frequency of revolution is found to be approximately half the ratio of the total length of straight sections to the orbit circumference. The effect of magnetic fringing fields is considered. With regard to the synchrotron phase oscillation, it is found that the criterion of non-relativistic adiabatic damping is no longer that n exceed ⅔ but that it exceed ⅔ by at least ⅓ of the ratio of the total length of the straight sections to the orbit circumference.

Description of Two Species of Cephalaspis

Abstract A new form of Cephalaspis (C. Asterolepis ) was found by the author about two years ago at Hopton Gate, about four miles east of Ludlow, in a bed of coarse Old Red conglomerate overlying a compact calcareous sandstone, which latter abounds with fragments of Cephalaspis Lyellii and Pteraspis , and in its upper part contains remains of Pterygotus problematicus ? The former is horizontally bedded, and alternates with a brown micaceous shale, in which are carbonized fragments of plants. Cephalaspis Asterolepis from the Old Red Sandstone of the neighbourhood of Ludlow is by far the largest species that has been discovered, the cephalic plate having at least twice the dimensions of that of C. Lyellii . In outline it is broadly semielliptical. In addition to its large size, it is distinguished by the position, obliquity, and magnitude of the orbits. Placed almost entirely on the posterior half of the shield, these diverge from each other so as to be distant 1 inch apart anteriorly, and ½ an inch posteriorly. The long diameter of each orbit measures 1 ¼ inch. Within the orbital circumference remains of the osseous sclerotica are visible. Owing to the backward position of the orbits, it is in the posterior of the shield that we find some of the chief distinctive modifications: thsu the occipital crest is even shorter than that of a species less than half its size; the space between the orbital ridges is proportonately small. The outer enamel-layer is ornamented with tubercles, which bear so close a resemblance to those covering the bony plates of Asterolepis as to have suggested the specific name. They present, however, considerable variation: usually they arise by a circular and more or less tumid base, which gradually terminates in an elevated papilla; or the papilla may be small, rounded, and distinct from the base. Sometimes two or even three minute papillæ surmount the same base; sometimes the base is quite flat and expanded, and is occupied by a solitary central papilla. In all cases the base presents more or less distinctly a radiated striation. The inner layer of the bony plate presents lacunæ and long branching canaliculi precisely resembling those of human bone. Many of these are completely injected with a transparent blood-red material; and so beautifully are they displayed, that one ignorant of the structure of bone would be able to apprehend it by a glane at a minute part of this ancient fragment. So wonderfully indeed has nature treasured up her secrets in this disentombed relic of a time so distant as to be incalculable, that she distinctly reveals in their minutest details the structure of canals not more than the one-fifty-thousanth of an inch in diameter, and such as defy the skill of the anatomist to inject. Mr. Harley also described a more perfect specimen of Cephalaspis Salweyi than the one on which Sir P. Egerton not long since determined the species*. It was found by Mr. Salwey at Hinstone near Bromyard, and about 1 ½ mile from Acton Beauchamp, in a sandtone similar to that in which the other specimen was found at Acton Beauchamp. Cephalaspis Salweyi proves to differ but very little in size and external configuration from C. Lyellii . It is distinguished from this species by its short and slender postero-lateral spines, which are not prolonged further backwards than the termination of the occipital crest. The internal parts of the posterior third of the shield form a distinct, arched, nuchal plate, which is prolonged posteriorly. The occipital crest is prominent, and bifurcates anteriorly into the orbital ridges. These, diverging, curve a little outwards and pass to the posterior margins of the orbits, enclosing between them a tabulated surface, which, occupying the central and most elevated parts of the general surface, forms a prominent feature. The orbits are small and slightly oval; they are situated entirely on the anterior half of the shield. The enamel-layer forms small, oblong or round, pearly drop-like tubercles, which are numerous an for the most part discrete. The space between them are grooved into parallel or slightly divergent ridges, which pass from their sides and ends. The structure of these tubercles is very vascular. Associated with this fossil, the author found the dermal plate or the tooth of a placoid fish, which has close resemblance to the teeth of Cestracion and the Rays, and even closer still with the bone of the Silurian bodies called by Pander Cœlolepidœ . It was discovered almost between the jaws of C. Salweyi , and thus suggests the paradoxical question—does it belong to that fish?