• Title/Summary/Keyword: Skeletal structures

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Analysis of effects from usage of skeletal anchorage-assisted Pendulum appliance on vertical component of craniofacial structure (골격고정원을 이용한 Pendulum 장치가 두개 안면의 수직적 요소에 미치는 효과 분석)

  • Lee, Jin-Woo
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.1
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    • pp.10-16
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    • 2018
  • Purpose: The purpose of this study was to evaluate distalizing effects from the Pendulum appliance on vertical component of craniofacial structures. Materials and Methods: 20 Patients who visited for orthodontic treatments are assigned to two groups. Group I, SN-MP > 37 degrees are showing hyperdivergent pattern. Group II, 29 < SN-MP < 37 degrees are showing mesocephalic pattern. Each group are consisted of 10 people. Results and Conclusions: Differences between skeletal classifications result in significant differences at labioversion of lower incisors and distalized amount, which is larger at Group I (P <.05). Group II has only shown significant distalized molars (P < .05). Labioversion of lower incisors has not shown significant change. Skeletal anchorage-assisted Pendulum appliance doesn't deteriorate vertical component nor significantly improve.

COMPARATIVE STUDY ON MUSCLE ACTIVITIES OF PRE- AND POST-ORTHOGNATHIG SURGERY IN SKELETAL CLASS III MALOCCLUSION PATIENTS AND NORMAL GROUP (성인에서 골격형 제 III급 부정교합자의 악교정 수술 전, 후와 정상교합자의 근활성도에 대한 비교연구)

  • Jung, Kyung-Jin;Sohn, Byung-Wha
    • The korean journal of orthodontics
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    • v.25 no.3 s.50
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    • pp.355-373
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    • 1995
  • Craniofacial region is a musculodentoskeletal system that consists of many anatomical structures ; cranioskeletal structures, dental arches, and formation and functions of masticatory muscles have close correlations. Growth and development of craniofacial region are influenced by not only hereditory factors, but also environmental factors such as craniofacial muscles and surrounding tissues. On the contrary, however, study on changes in functions or adaptations of craniofacial muscles following changes of craniofacial skeletal structures has been somewhat insufficient. The author's purpose was to observe correlations between masticatory muscular functions and change patterns according to cranial skeletal structures and occlusion patterns, for this, comparative study of muscle activity changes of preand post- orthognathic surgery states in skeletal Cl III malocclusion patients was peformed. The selected sample groups were 15 normal male patients, 15 skeletal Cl III pre-orthognatic surgery patients and 15 skeletal Cl III post-orthognatic surgery patients. For each sample groups, cephalometric x-ray taking, masticatory efficiency test and measurements of muscle activities in anterior temporal muscle, masseter and upper lip in rest, clenching, chewing and swallowing were carried out. The following results were obtained : 1. In resting state of mandible, pre-surgery malocclusion group showed higher m. activities in ant. temporalis, masseter and upper lip than post-surgery group. Post-surg. malocc. group showed significantly high m. activity only in upper lip compared to the normal group. 2. In clenching state, post-surg. malocc. group showed higher m. activities in ut. temporalis, masseter and upper lip than pre-surg. malocc. group. 3. In chewing state, post-surg. malocc. group showed higher m. activities in ant. temporalis and masseter than pre-surg. malocc. group, on the other hand, decreased upper lip activity was noticed. 4. In swallowing state, post-surg. malocc. group showed lower upper lip activity than pre-surg. malocc. group but higher than that of the normal group. No significant difference in m. activities of ant, temporalis and masseter was noticed among the three groups. 5. Masticatory efficiency was lower in pre-surg. malocc. group than normal group, masticatory efficiency showed an increase in post-surg. malocc. group compared to the pre-surg. malocc. group. However, both groups showed significant differences compared to the normal group.

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The stability of semi-rigid skeletal structures accounting for shear deformations

  • Gorgun, Halil
    • Structural Engineering and Mechanics
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    • v.57 no.6
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    • pp.1065-1084
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    • 2016
  • The analysis and design of skeletal structures is greatly influenced by the behaviour of beam-to-column connections, where patented designs have led to a wide range of types with differing structural quantities. The behaviour of beam-to-column connections plays an important role in the analysis and design of framed structures. This paper presents an overview of the influence of connection behaviour on structural stability, in the in-plane (bending) mode of sway. A computer-based method is presented for geometrically nonlinear plane frames with semi-rigid connections accounting for shear deformations. The analytical procedure employs transcendental modified stability functions to model the effect of axial force on the stiffness of members. The member stiffness matrix were found. The critical load has been searched as a suitable load parameter for the loss of stability of the system. Several examples are presented to demonstrate the validity of the analysis procedure. The method is readily implemented on a computer using matrix structural analysis techniques and is applicable for the efficient nonlinear analysis of frameworks. Combined with a parametric column effective length study, connection and frame stiffness are used to propose a method for the analysis of semi-rigid frames where column effective lengths are greatly reduced and second order (deflection induced) bending moments in the column may be distributed via the connectors to the beams, leading to significant economies.

Synthesis, Structures, and Catalytic Properties of Ionic Metallacyclodimeric Palladium(II) Complexes

  • Kim, Sung Min;Park, Kyung Hwan;Lee, Haeri;Moon, So Yun;Jung, Ok-Sang
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4069-4073
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    • 2012
  • Metallacyclodimeric complexes of $[(Me_4en)Pd(L)]_2(ClO_4)_4$ ($Me_4en$ = N,N,N',N'-tetramethylethylenediamine; L = dimethylbis(4-pyridyl)silane (dmps), methylvinylbis(4-pyridyl)silane (mvps)) have been synthesized, and their structures have been characterized by X-ray single crystallography. The skeletal structures consist of one 20-membered metallamacrocycle, two 5-membered metallacycles, and four pyridyl groups. The local geometry around the palladium(II) ion approximates to a typical square planar arrangement with four nitrogen donors. Delicate difference in catalytic effects on hydrogenation was investigated based on the structure of catalyst and substrates.

An iterative method for damage identification of skeletal structures utilizing biconjugate gradient method and reduction of search space

  • Sotoudehnia, Ebrahim;Shahabian, Farzad;Sani, Ahmad Aftabi
    • Smart Structures and Systems
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    • v.23 no.1
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    • pp.45-60
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    • 2019
  • This paper is devoted to proposing a new approach for damage detection of structures. In this technique, the biconjugate gradient method (BCG) is employed. To remedy the noise effects, a new preconditioning algorithm is applied. The proposed preconditioner matrix significantly reduces the condition number of the system. Moreover, based on the characteristics of the damage vector, a new direct search algorithm is employed to increase the efficiency of the suggested damage detection scheme by reducing the number of unknowns. To corroborate the high efficiency and capability of the presented strategy, it is applied for estimating the severity and location of damage in the well-known 31-member and 52-member trusses. For damage detection of these trusses, the time history responses are measured by a limited number of sensors. The results of numerical examples reveal high accuracy and robustness of the proposed method.

Heterogeneity of Lactate Dehyrogenase Isozymes in tissues of Lampetra japonica (칠성장어(Lampetra japonica) 조직내 젖산수소이탈효소 동위효소들의 이질성)

  • 조성규;염정주
    • The Korean Journal of Zoology
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    • v.36 no.3
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    • pp.319-328
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    • 1993
  • All vertebrates other than lampreys exhibit multiple loci encoding lactate dehydrogenase (EC 1.1.1.27,LDH). From the result shown by cellulose acetate and starch gel electrophoresis, the lampreys were-reported to have only one isozyme. However in our results the LDH of skeletal muscle, heart and kidney in Lampetra japonica were separated into three isozymes and that of liver was separated into two isozymes by polyacrylamide gel electrophoresis. The LDH of skeletal muscle and heart were separated into four isozymes and that of liver was separated into two isozymes by polyacrylamide gel isoelectric focusing (PAGlEF). The LDH of skeletal muscle were separated into four isozymes through the chromatofocusing. The molecular weight of LDH isozymes in skeletal muscle was approximately estimated to be 140,000 by Sephadex G-200 gel filtration. The LDH isozymes of skeletal muscle, heart and liver were inhibited by pyruvate to the nearly similar degree. And the degree of inhibition by pyruvate showed the value between LDH A$_4$and LDH B$_4$isozyme. And the LDH isozymes in heart, liver and skeletal muscle were thermostable. The results mentioned above indicate that the LDH isozyme in lamprey (Lampetra japonica) has not one isozyme but isozymes. And it is also found out that the two structures of their subunits are similar each others.

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Osteological Development of Larvae and Juveniles of Sea Raven, Hemitripterus villosus in Coastal Waters off Yeosu (여수 연안산 삼세기(Hemitripterus villosus) 자치어의 골격발달)

  • Na-Young Jeon;Ae-Jeon Park;Sung-Hoon Lee;Tae-Sik Yu;Kyeong-Ho Han
    • Korean Journal of Ichthyology
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    • v.36 no.1
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    • pp.20-29
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    • 2024
  • Hemitripterus villosus, a promising aquaculture fish species, is facing declining stocks. This study aims to provide normative standards for skeletal development to address persistent skeletal deformities in farmed fish. Specimens utilized in the study underwent artificial insemination with captured fish, and the resulting larvae and fry were preserved in a formalin solution. The skeletal ossification process commenced immediately after hatching, affecting the parasphenoid, premaxillary, maxillary, and dentary structures at an average total length of 13.65±0.71 mm (n=5). By sixty-five days post-hatching, ossification extended to the ethmoid and supraorbital, completing the head's development at an average total length of 21.24±0.50 mm (n=5). Clavicle ossification occurred at seven days post-hatching, corresponding to an average total length of 14.61±0.52 mm (n=5). At forty-four days post-hatching, the ossification of 4 actinosts took place, completing the shoulder girdle, with an average total length of 18.15±0.61 mm (n=5). Vertebral ossification initiated at ten days post-hatching, with an average total length of 14.80±0.65 mm (n=5). By fifty-four days post-hatching, 39 vertebral columns were ossified, reaching an average total length of 18.67±0.54 mm (n=5). Vertebral development was complete at sixty days post-hatching, with an average total length of 20.25±0.45 mm (n=5). This study sheds light on the skeletal development of H. villosus, providing valuable standards and fundamental data for understanding skeletal deformities in this species.

Optimization of modular Truss-Z by minimum-mass design under equivalent stress constraint

  • Zawidzki, Machi;Jankowski, Lukasz
    • Smart Structures and Systems
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    • v.21 no.6
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    • pp.715-725
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    • 2018
  • Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks. The previous research on TZ focused on global discrete geometric optimization of the spatial configuration of modules. This paper reports on the first attempts at structural optimization of the module for a single-branch TZ. The internal topology and the sizing of module beams are subject to optimization. An important challenge is that the module is to be universal: it must be designed for the worst case scenario, as defined by the module position within a TZ branch and the geometric configuration of the branch itself. There are four variations of each module, and the number of unique TZ configurations grows exponentially with the branch length. The aim is to obtain minimum-mass modules with the von Mises equivalent stress constrained under certain design load. The resulting modules are further evaluated also in terms of the typical structural criterion of compliance.

Theoretical Study of the Lowest Energy Structure of the Water Undecamer

  • Lee, Han-Myoung
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.777-779
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    • 2003
  • Density functional calculations and ab initio calculations have been carried out to study the lowest energy structure of the water ($H_2O)_{11}$. Among five structures suggested by four different groups, the lowest energy structure is found to have the skeletal structure of Prism56 (Pr56-24) that a cyclic pentamer and a cyclic hexamer are fused into a prism-shape with 16 hydrogen-bonds (HBs).