Type Of Deformation Research Articles

Analysis on mechanical behavior and failure characteristics of layered cemented paste backfill(LCPB) under triaxial compression

To explore the mechanical properties and energy evolution law of layered cemented paste backfill (LCPB), LCPB specimens layer numbers of 1, 2, 3 and 4 were made, and triaxial compression tests with confining pressures of 0, 0.2, 0.5 and 0.8 MPa were carried out. Combined with the principle of energy evolution, the damage and failure law of LCPB were analyzed in depth. The results show that: (1) The failure type of LCPB is mainly a tensile failure, and the failure plane mainly appears in the later layers. Relative to the failure deformation, the elastic energy increases first and then decreases, and the elastic energy reaches its maximum at the peak stress point. (2) The peak strength increases linearly with the increase of confining pressure and decreases linearly with the increase of layer number. The peak strain increases exponentially with the increase of confining pressure and layer number. The elastic modulus increases exponentially with the increase of confining pressure and decreases logarithmically with the increase of layer number. (3) According to the different deformation types of LCPB, three failure constitutive models of plastic-elastic–plastic type, elastic–plastic type and elastic–plastic-viscous type were built respectively, and the accuracy of the models was verified by the coincidence degree with the test curves. (4) The ultimate elastic energy, failure dissipated energy and failure constitutive energy all show obvious confining pressure effect and layer effect, and the damage value at the peak point decreases first and then increases with the increase of confining pressure.

The Italian Spine Youth Quality of Life questionnaire: reliability and validity of the Persian version in adolescents with spinal deformities

To assess the reliability and validity of the Persian version of the Italian Spine Youth Quality of Life (P-ISYQOL) questionnaire. Forward/backward translations and cultural adaption processes of the ISYQOL questionnaire into Persian were conducted by an expert committee. We recruited 178 adolescents with idiopathic scoliosis (AIS) and Scheuermann's kyphosis (SK) and 103 age-matched adolescents with no spinal deformity. Reliability was assessed by evaluating internal consistency and test-retest reliability using Cronbach's alpha and intraclass correlation coefficient (ICC). Convergent construct validity was assessed by measuring the association between the ISYQOL and revised 22-item Scoliosis Research Society (SRS-22r) questionnaires scores. Known-groups construct validity was assessed regarding curve magnitude, deformity, age, sex, and treatment type. Cronbach's alpha and ICC for P-ISYQOL total score was 0.8 and 0.9, respectively. An acceptable association was observed between P-ISYQOL and SRS-22r total scores (r = - 0.5, p < 0.01). The P-ISYQOL could discriminate between adolescents with spinal deformities and adolescents with no spinal deformity as well as those with different types of deformity and treatment (p < 0.01). The P-ISYQOL is a reliable and valid survey to assess the outcomes of adolescents with spinal deformities. Level I-diagnostic studies.

Effects of helium cavity size and morphology on the strength of pure titanium

High-purity α-titanium was implanted with helium to observe cavity morphology – size, number density, and form (i.e., bubbles vs. voids) – effects on materials strength. Increasing implantation temperatures lead to an Arrhenius-type (i.e., exponential) increase in cavity size, a transition from spherical bubbles to faceted voids, and a marked increase in strength (∼20–50%). Implanted samples deformed uniformly in contrast to nano-compression of unimplanted or alloyed titanium, but pillars with the largest faceted voids developed a type of bulging localized deformation. Affected voids were repeatedly sheared, becoming rough and shrunken. Dislocation-cavity interactions and the role of helium content within cavities are considered.

Effects of shear on development characteristics of organic matter pores in shale: A case study of shale in the Niutitang Formation of the well XAD1

The development characteristics of organic matter pores (OMPs) in shales is fundamental to the gas-bearing property of the shales. Detachment is one of the most common types of structural deformation in shale formations. To investigate the characteristics of OMPs in shear-deformed shale and the associated effects on the pore structure of shale gas reservoir, two sets of detachment zones and the intercalated non-detachment zone of shale formations in the Niutitang Formation of the Well XAD1 are studied. Based on scanning electron microscope observations and low-pressure gas adsorption tests, the impacts of shear on the shale pore structure are evaluated quantitively and the deformation mechanism for OMPs in shale is established.Results indicate that the dominant pore type of shale in the Niutitang Formation of the Well XAD1 is OMPs. With the mineral rheology, organic matters are enriched in the clay gouge, which are more prone to shear deformation compared with those outside the gouge. Under shear, pores developed within the organic matter experienced directional elongation and compression, decreasing the pore sizes and lowering the volumes of the corresponding pores <30 nm; and the contact surface between organic matter and minerals becomes dislocated and open, increasing the volumes of the corresponding pores >30 nm. The effect of shear on OMPs is dominated by pore reduction. The volume loss ratio of shale micropores in detachment zones is the highest which can reach over 90%. The impact of shear on pore structures of non-detachment zone cannot be neglected within the thickness range of 5–20 m from the detachment surface, and the degree of pore reduction gradually decreases as the distance from the detachment zones increases. It is indicated that the detachment and its adjacent horizons are not favorable for shale gas exploration because of the low porosity and adsorption capacity.

Alteration of the Sitting and Standing Movement in Adult Spinal Deformity.

Adults with spinal deformity (ASD) are known to have spinal malalignment affecting their quality of life and daily life activities. While walking kinematics were shown to be altered in ASD, other functional activities are yet to be evaluated such as sitting and standing, which are essential for patients’ autonomy and quality of life perception. In this cross-sectional study, 93 ASD subjects (50 ± 20 years; 71 F) age and sex matched to 31 controls (45 ± 15 years; 18 F) underwent biplanar radiographic imaging with subsequent calculation of standing radiographic spinopelvic parameters. All subjects filled HRQOL questionnaires such as SF36 and ODI. ASD were further divided into 34 ASD-sag (with PT > 25° and/or SVA >5 cm and/or PI-LL >10°), 32 ASD-hyperTK (with only TK >60°), and 27 ASD-front (with only frontal malalignment: Cobb >20°). All subjects underwent 3D motion analysis during the sit-to-stand and stand-to-sit movements. The range of motion (ROM) and mean values of pelvis, lower limbs, thorax, head, and spinal segments were calculated on the kinematic waveforms. Kinematics were compared between groups and correlations to radiographic and HRQOL scores were computed. During sit-to-stand and stand-to-sit movements, ASD-sag had decreased pelvic anteversion (12.2 vs 15.2°), hip flexion (53.0 vs 62.2°), sagittal mobility in knees (87.1 vs 93.9°), and lumbar mobility (L1L3-L3L5: −9.1 vs −6.8°, all p < 0.05) compared with controls. ASD-hyperTK showed increased dynamic lordosis (L1L3–L3L5: −9.1 vs −6.8°), segmental thoracic kyphosis (T2T10–T10L1: 32.0 vs 17.2°, C7T2–T2T10: 30.4 vs 17.7°), and thoracolumbar extension (T10L1–L1L3: −12.4 vs −5.5°, all p < 0.05) compared with controls. They also had increased mobility at the thoracolumbar and upper-thoracic spine. Both ASD-sag and ASD-hyperTK maintained a flexed trunk, an extended head along with an increased trunk and head sagittal ROM. Kinematic alterations were correlated to radiographic parameters and HRQOL scores. Even after controlling for demographic factors, dynamic trunk flexion was determined by TK and PI-LL mismatch (adj. R 2 = 0.44). Lumbar sagittal ROM was determined by PI-LL mismatch (adj. R 2 = 0.13). In conclusion, the type of spinal deformity in ASD seems to determine the strategy used for sitting and standing. Future studies should evaluate whether surgical correction of the deformity could restore sitting and standing kinematics and ultimately improve quality of life.

Extended flexibility of Lyapunov exponents for Anosov diffeomorphisms

Bochi-Katok-Rodriguez Hertz proposed recently a program on the flexibility of Lyapunov exponents for conservative Anosov diffeomorphisms, and obtained partial results in this direction. For conservative Anosov diffeomorphisms with strong hyperbolic properties we establish extended flexibility results for their Lyapunov exponents. We give examples of Anosov diffeomorphisms with the strong unstable exponent larger than the strong unstable exponent of the linear part. We also give examples of derived from Anosov diffeomorphisms with the metric entropy larger than the entropy of the linear part. These results rely on a new type of deformation which goes beyond the previous Shub-Wilkinson and Baraviera-Bonatti techniques for conservative systems having some invariant directions. In order to estimate the Lyapunov exponents even after breaking the invariant bundles, we obtain an abstract result which gives bounds on exponents of some specific cocycles and which can be applied in various other settings. We also include various interesting comments in the appendices: our examples are C 2 \mathcal {C}^2 robust, the Lyapunov exponents are continuous (with respect to the map) even after breaking the invariant bundles, a similar construction can be obtained for the case of multiple eigenvalues.

Investigating Multiaxial Mullins Effect of Carbon-Black-Reinforced Elastomers Using Electrical Resistivity Measurements

The Mullins effect is commonly observed in the mechanical properties of elastomer/filler composites: The stress during unloading or second loading is considerably lower than the first loading stress. We measured the mechanical stresses and electrical conduction to investigate the Mullins effect in carbon-black (CB)-reinforced elastomers under various biaxial stretching. Imposing the small equibiaxial strain of 30% increases the electrical surface resistivity in the deformed state by more than 3 orders of magnitude, indicating the breakdown of the initial conductive percolated CB network. The resistivity of the relaxed unloaded states (ρS), representing the degree of residual destruction of the CB network, increases with the biaxial strain for small imposed deformation. However, ρS saturates at large deformations, indicating that the residual CB-network destruction does not increase further. The mechanical dissipation factor (Δ; the ratio of energy dissipation to input work) and ρS obtained at various degrees and types of deformation can be described by a single variable, i.e., the first invariant of deformation tensor. This indicates that the orthogonal strains cause the residual damage of the CB network and the internal mechanical damage.

Optomechanical Properties of MoSe2 Nanosheets as Revealed by In Situ Transmission Electron Microscopy.

Free-standing few-layered MoSe2 nanosheet stacks optoelectronic signatures are analyzed by using light compatible in situ transmission electron microscopy (TEM) utilizing an optical TEM holder allowing for the simultaneous mechanical deformation, electrical probing and light illumination of a sample. Two types of deformation, namely, (i) bending of nanosheets perpendicular to their basal atomic planes and (ii) edge deformation parallel to the basal atomic planes, lead to two distinctly different optomechanical performances of the nanosheet stacks. The former deformation induces a stable but rather marginal increase in photocurrent, whereas the latter mode is prone to unstable nonsystematic photocurrent value changes and a red-shifted photocurrent spectrum. The experimental results are verified by ab initio calculations using density functional theory (DFT).

Deciphering the deformation mechanism in Quaternary deposits along the Idrija Fault in the formerly glaciated Soča Valley, southeast European Alps

Deciphering deformation mechanisms within Quaternary sediments in a highly dynamic environment such as the southeast European Alps is often a challenging task that requires the use of a variety of methods. Due to the geohazards involved, the interpretation of deformation mechanisms can have a major impact on society and may enable the preparation of appropriate engineering solutions. We present an example of how deformation structures can be studied by integrating geomorphological, sedimentological and structural geological mapping using photogrammetric and leveling surveys, paleoseismological techniques, optically stimulated luminescence dating and ground penetrating radar surveys. Quaternary deposits on the slopes of the formerly glaciated Soča Valley near Most na Soči are tilted and dissected along numerous faults within the deformation zone of the Idrija Fault, a large, active, dextral strike-slip fault. Reconstruction of deformation history indicates that at least five deformation events occurred during deposition of the glaciofluvial succession interbedded with glaciolacustrine deposits, dated to Penultimate Glaciation. Ground penetrating radar profiles and outcrop observations reveal NE – SW striking faults, which are approximately perpendicular to the primary Idrija Fault. Based on the local geologic setting, we considered glaciotectonics, gravitational faulting due to ice-decay collapse or slope instability, and tectonic faulting as possible deformation mechanisms. Based on detailed documentation and analysis of the geometry and kinematics of the deformations, we interpret the observed deformations as secondary structures that result from paleoseismic activity of the Idrija Fault, and some structures resulting from glaciotectonics and gravitational faulting. The transtensional type of deformations at the studied site shows the local character of the main fault, which occurs here due to geometrical and kinematical changes of the Idrija Fault causing local transtension in the Most na Soči area. The complexity of the fault and the first paleoseismic evidence dating back to Penultimate Glaciation provide valuable new data for understanding the seismic hazard in the region.

Correlation between phase transformation and surface morphology under severe plastic deformation of theAl87Ni8La5 amorphous alloy

The parameters of shear bands and their relationship with the nanocrystallization process in the Al87Ni8La5 amorphous alloy under deformation were studied by X-ray diffraction, high resolution electron microscopy, and atomic force microscopy. Deformation of the samples was carried out by room temperature rolling and high pressure torsion methods. An increase in the deformation level was found to lead to an increase in the surface roughness, an increase in the step height, and the formation of Al nanocrystals. The thickness of the shear band, determined from the width of the minimum steps, does not depend on deformation type and is approximately 15 nm; the height of the minimum steps ranges from a few tenths of nm to 1.5 nm. The formation of nanocrystals occurs when the shear band power corresponding to the true deformation e = 4.42 is reached.

Hierarchical Au/CeO2 systems – influence of Ln3+ dopants on the catalytic activity in the propane oxidation process

The catalytic activity of the hierarchical tube-like Au/Ce1−xLnxO2−x/2 in the propane oxidation process depends not only on the presence of Au nanoparticles on the support surface but also on the type of deformation in the CeO2 network.

Термическая стабильность структуры стали ЭИ-961Ш после комбинированной обработки

A crucial aspect in the development of materials with improved functional properties is ensuring their ability to withstand the operating temperatures of a finished product. To increase the service life and efficiency of products made of ferrite-martensite steels, various types of deformation and thermal treatments are used. The authors studied the influence of different temperature regimes on the structure and thermal stability of ЭИ-961Ш ferrite-martensite steel subjected to rolling and additional hardening. As a method of deformation and heat treatment, the authors used cold rolling followed by re-quenching from a temperature above the ferrite/austenite phase transition. The samples were rolled during several passes on a laboratory rolling mill with the deformation of 6 % per pass for a final thickness of 4.3 mm to a reduction degree of 70 %. The authors carried out structural studies by transmission electron microscopy and scanning electron microscopy. The study showed that as a rolling result, a bimodal band structure forms with the distribution of Cr23C6 carbide particles along the grain boundaries. When using additional hardening, an increase in the globular carbides proportion is observed, and during the study by transmission electron microscopy, nano-twins were found in the structure. The bands’ width after the reduction by 50 % was 0.5 microns and after cold rolling and additional heat treatment – 0.4 microns. The authors carried out short annealing in the operating temperature range to study the thermal stability of ferrite/martensite steel structure after cold rolling and additional heat treatment. The thermal stability study showed that many structural features formed during previous deformation and heat treatment are preserved, however, after annealing at 600 °C, there are no visually observable nano-twins in the structure.

ДОСЛІДЖЕННЯ НЕСУЧОЇ ЗДАТНОСТІ МЕТАЛЕВИХ КОНСТРУКЦІЙ ЗА НАЯВНОСТІ В НИХ ТРІЩИН

The article discusses the urgent problem of the bearing capacity of structural elements that have defects in the form of cracks, which negatively affects the performance of the object. There is premature, sometimes sudden destruction even under the action of minor loads, cracks can be technological: occur during casting, forging, welding, as well as acquired; during installation of the object or operation (from overload), the occurrence of cracks also depends on the type of load:static, alternating and dynamic; from the type of deformation: tensile-compression, displacement, torsion, bending, as well as from the physical and mechanical characteristics of the material and the geometry of the object. Practice shows that the presence of a crack does not mean the loss of the bearing capacity of the structure: up to the critical size of the crack, damage can be safe if it is possible to detect and track the development of a defect, which will be the justification for the further operation of the valuable object. Taking into account the complexity of the problem under consideration, the solution is carried out by the method of energy balance. Its essence is as follows. Elastic bodies in the process of deformation accumulate the potential of mechanical energy. It cannot disappear without a trace, and in the presence of a crack, it accumulates on the surfaces of its banks, more precisely in the deformation of the tension of these banks, leading to the development of a crack. The critical state of crack resistance is determined by the ratio between the intensity coefficients of stresses (KIN), which reflect the size of the crack and the acting stresses. In this case, the design will be inoperable, or such that the process of destruction can be prolonged in time.

Boudin Types, Their Morphology and Significance in Interpreting Deformational History in Proterozoic Rocks of North Delhi Fold Belt, North Western India

The boudins can be of symmetric as well as asymmetric type and can help in determining shear sense and help unfold the deformational history, hence are important structure for recognizing the history of deformation in an area; Once the rocks of an area undergo polyphase of deformation, the boudins get modified and can no longer help in determining the deformational evidences. The present study involves identification of various types of boudins their classification and morphology as per existing status of knowledge and their role in determining the type of deformation in Neem Ka Thana belt, Proterozoic rocks of North Delhi fold belt. The study of symmetric, asymmetric and modified boudins in the area enabled the author to deduce that the rocks in above belt have suffered a ployphase deformation marked with flattening type of progressive deformation during the first phase (DF1) of deformation and the second phase (DF2) with a time gap, has produced modified boudins and folded boudin structures with the largely same axis of deformation in both these deformations.

Study Restraint Pressure of Membranes on Expansive Soil

Type of deformation in expansive soil is lateral and vertical Laboratory expansion tests are often performed on rings with restrained, lateral movement so that horizontal, swelling deformation will not occur. The road damage in the highway between Purwodadi – Semarang (Begel village, Purwodadi) was identified because the soil is expansive. Therefore, this study was conducted to identify characteristics of its soil expansion, specifically the influence of pressure of membrane restraints on expansion of expansive soil. The expansion test was conducted on modified test tools. The axial expansion strain was measured using the dial gauge which was installed in parallel, vertical position while the lateral strain was measured using the caliper digital in order to identify any change in the diameter of sample with the variations of initial water content (wo), vertical pressure (pv) and membrane’s thickness (t). The test result show that the greater the (horizontal) lateral strain is, the greater the restraint pressure in the membranes will be. The restraint pressure in the membranes (ph) is closely related to factors that influence the expansion possibility such as vertical pressure (pv), initial height of test object (ho), initial water content (wo), and membrane’s thickness (t).

Etiopathogenetic features, course and outcome of hemorrhagic stroke in young people

Analysis of etiopathogenetic factors and features of the course of hemorrhagic stroke in young people. A retrospective analysis of 402 case histories with non-traumatic hemorrhagic stroke was carried out, of which 60 (14.93%) patients were young. The average age was 37.37±5.09 years. There were 19 (31.7%) females and 41 (68.3%) males. Statistical data processing was carried out using Microsoft Office 2010 and SPSS v.26. The main causes of hemorrhagic stroke in young people were changes in cerebral vessels by the type of aneurysmal deformation of the vascular wall, including Moya-Moya disease, and arteriovenous malformations (60%). The second etiological factor of hemorrhagic stroke was arterial hypertension (40%). Intracerebral hematoma was the most common type of hemorrhagic stroke. The functional outcome was influenced by: the severity of the patient's general condition, the severity of the neurological deficit, the degree of consciousness, the presence of concomitant pathology, convulsive, dislocation syndrome, leukocytosis, hyperglycemia, high creatinine levels. The problem of hemorrhagic stroke at a young age is complex and relevant, since the etiological factor of the disease at this age differs significantly from that in older age groups, requires adequate diagnostic searches to identify the etiopathogenetic factor and subsequent secondary prevention.

CLINICAL AND FUNCTIONAL ANALYSIS AFTER TOTAL KNEE ARTHROPLASTY.

ABSTRACTOsteoarthritis is a major cause of disability worldwide. Objective: To evaluate the effects of Total Knee Arthroplasty of subjects with knee osteoarthritis by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC ). Methods: Prospective, non-randomized study with convenience sampling. We included subjects with knee osteoarthritis with indication for surgical treatment. We used WOMAC to evaluate the level of pain, joint stiffness, physical activity, and quality of life in the preoperative and postoperative phase six months after unilateral surgery. We compared WOMAC to the factors age, gender, Body Mass Index and the type of angular deformity of the knee. Results: In total, we analyzed 58 patients with significant improvements in pain relief, joint stiffness, level of physical activity, and quality of life six months after total knee arthroplasty according to WOMAC. Conclusion: Total knee arthroplasty showed positive effects on the quality of life of patients with knee osteoarthritis. Level of Evidence II, Cohort Study.

Effcets of Synthetic Food Colourants on Spermatogenesis and Alteration in Cauda Epididymal Sperm Characteristics of Swiss Albino Mice

The present study examined effects of Azorubine (E122) and Amaranth (123) on male reproductive system of Swiss albino mice. Control (Group I, n=20) was treated with vehicle. Two treatment groups based on azorubine (Group II) and amaranth (Group III) treatment were designed with sub-groups for doses 1/2LD50 and 1/4LD50 (Group IIa, Group IIb, Group IIIa and Group IIIb) consisting of 20 animals each. Five animals from each group and sub-group were sacrificed at 7th, 14th, 21st, and 28th day of administration. Body and testis weight were measured, along with cauda sperm characteristics and testicular histology. Level of reproductive hormones were also examined. Results showed significant deterioration of sperm characteristics after treatment with both dyes. Major types of sperm deformities noticed in azorubine and amaranth treated animals were broken tail, bend tail, cytoplasmic droplet, head-tail separation, coiled tail, and headless sperms. More than 30% decline in motility and abnormality was noted in animals treated with amaranth. Histological observation indicated cytotoxic damages in amaranth treated mice, while azorubine treated animals exhibited large scale disorganization of germ cells and interference in spermatogenesis. Conclusively, azorubine and amaranth at the doses used in this study were detrimental to spermatogenesis. Deformities found in the cauda epididymal sperms indicated consequential impact on the rate of fertility.

Percutaneous Bunionette Correction without Fixation: Clinical Results and Radiographic Evaluations Including Rotation of Metatarsal Head and Sagittal Angular Change of Fifth Metatarsal

Category:Lesser ToesIntroduction/Purpose:Bunionette has been treated as an analogy of hallux valgus, and the surgical techniques are similar. However, only the anteroposterior image is generally evaluated pre- and postoperatively. There are few studies that evaluated on the lateral radiograph, and to the best of our knowledge, no study that evaluated changes in rotation of fifth metatarsal head. In percutaneous bunionette correction using a burr, shortening of fifth metatarsal and elevation of metatarsal head are inevitable. In addition, there is also the possibility of rotational change of metatarsal head without fixation.Methods:We evaluated 18 consecutive feet performed percutaneous bunionette correction without internal fixation. Mean age was 54.9 years. Mean follow-up was 10.1 months at least six months followup. On anteroposterior weightbearing radiograph, we measured the fifth metatarsophalangeal angle (MPA), fourth and fifth intermetatarsal angle (IMA), the fifth metatarsal head width (MHW), the lateral deviation angle (LDA) of the fifth metatarsal, and fifth metatarsal shortening. On the lateral weightbearing radiograph, we measured the lateral inclination angle (LIA) of the fifth metatarsal, the fifth distal metatarsal height (DMH), mid metatarsal height (MMH), proximal metatarsal height (PMH), and plantar bowing angle (PBA). To evaluate the rotation of the fifth metatarsal head, we devised a new original method measured at the medial tubercle location (MTL). Preoperatively and at the most recent follow-up visit, we applied the Japanese Society for Surgery of the Foot (JSSF) lesser scale and visual analogue pain scale (VAS).Results:Except for MTL, DMH and PMH, all parameters showed significant changes postoperatively.MPA, IMA and LDA reduced from 17.3 degrees to 6.4 degrees, from 9.9 degrees to 4.5 degrees, and from 2.3 degrees to -10.0 degrees, respectively. Shortening of fifth metatarsal was 2.5 mm. Despite not performing partial head resection, MHW decreased from 12.1mm to 11.4 mm. LIA decreased from 9.2 degrees to 6.1 degrees. MMH decreased from 11.6 mm to 10.9 mm. PBA decreased from 7.0 degrees to -1.3 degrees. Union was obtained at 6.9 weeks. MTL reduced from 3.4 to 2.8 but not significantly. However, MTL changed in 15 of 18 feet (83.3%) postoperatively. JSSF lesser scale improved from 66.7 to 97.8 points. VAS also improved from 3.6 to 1.0. One foot had a delayed union and an occasional pain.Conclusion:Percutaneous bunionette correction without fixation could achieved good clinical and radiographic results comparable with previously published outcomes of open and percutaneous surgery with fixation with less complication. The procedure could be adapted to different types of bunionette deformity. In this surgical method, bunionette is corrected in three dimensions.

Genel Anestezi Altındaki Ortognatik Cerrahi Prosedürlerinin Perioperatif Olarak Değerlendirilmesi: Retrospektif Bir Çalışma

Objective: The reconstruction of dentofacial deformities via orthognathic surgery is one of the procedures in oral and maxillofacial surgery. Several complications can occur-related to general anesthesia and prolonged operating time. The aim of this study was to investigate the effect of type of the skeletal deformity and the type of orthognathic surgery on anesthesia-related complications. Two hundred and two patients who underwent orthognathic surgery under general anesthesia were evaluated retrospectively. Material and Methods: According to inclusion criteria, 114 patients were included in the study. The patients were divided into two groups according to their surgical operations as single jaw (n=41) and double jaw (n=73) surgery. Ninety seven patients have skeletal Class 3 deformity and 17 patients have Class 2 deformity. The incidence of intraoperative surgical complications, duration of surgery, intubation difficulty, blood transfusion, postoperative intensive care and/or usage of additional medication were descriptively analyzed. Anesthesia-related complications were statistically compared between the groups. Results: The most common surgery-related complication was bad split. The incidence of life-threatening complications such as extensive blood loss or pulmonary edema was slightly higher in skeletal Class 2 patients and in double jaw surgery group. Although there was no statistically significant difference between the groups, both Mallampati score and difficult intubation scores were higher in skeletal Class 2 groups. Conclusion: Surgeon should be aware of prolonged surgery time can increase the complication risk while anesthesiologist should be aware of the Class 2 skeletal deformity-related intubation difficulties.