• Title/Summary/Keyword: Defects

Search Result 8,488, Processing Time 0.035 seconds

Reconstruction of large oroantral defects using a pedicled buccal fat pad

  • Yang, Sunin;Jee, Yu-Jin;Ryu, Dong-mok
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.40
    • /
    • pp.7.1-7.5
    • /
    • 2018
  • Background: Oroantral communicating defects, characterized by a connection between the maxillary sinus and the oral cavity, are often induced by tooth extraction, removal of cysts and benign tumors, and resection of malignant tumors. The surgical defect may develop into an oroantral fistula, with resultant patient discomfort and chronic maxillary sinusitis. Small defects may close spontaneously; however, large oroantral defects generally require reconstruction. These large defects can be reconstructed with skin grafts and vascularized free flaps with or without bone graft. However, such surgical techniques are complex and technically difficult. A buccal fat pad is an effective, reliable, and straightforward material for reconstruction. Case presentation: This report describes three cases of reconstruction of large oroantral defects, all of which were covered by a pedicled buccal fat pad. Follow-up photography and radiologic imaging showed successful closure of the oroantral defects. Furthermore, there were no operative site complications, and no patient reported postsurgical discomfort. Conclusion: In conclusion, the use of the pedicled buccal fat pad is a reliable, safe, and successful method for the reconstruction of large oroantral defects.

Atomic Force Microscopy Simulation for Si (001) Surface Defects (Si (001) 표면 결함 원자힘 현미경 전산모사)

  • Jo, Junyeong;Kim, Dae-Hee;Kim, Yurie;Kim, Ki-Yung;Kim, Yeong-Cheol
    • Journal of the Semiconductor & Display Technology
    • /
    • v.17 no.4
    • /
    • pp.1-5
    • /
    • 2018
  • Atomic force microscopy (AFM) simulation for Si (001) surface defects was conducted by using density functional theory (DFT). Three major defects on the Si (001) surface are difficult to analyze due to external noises that are always present in the images obtained by AFM. Noise-free surface defects obtained by simulation can help identify the real surface defects on AFM images. The surface defects were first optimized by using a DFT code. The AFM tip was designed by using five carbon atoms and positioned on the surface to calculate the system's energy. Forces between tip and surface were calculated from the energy data and converted into an AFM image. The simulated AFM images are noise-free and, therefore, can help evaluate the real surface defects present on the measured AFM images.

Random topological defects in double-walled carbon nanotubes: On characterization and programmable defect-engineering of spatio-mechanical properties

  • A. Roy;K. K. Gupta;S. Dey;T. Mukhopadhyay
    • Advances in nano research
    • /
    • v.16 no.1
    • /
    • pp.91-109
    • /
    • 2024
  • Carbon nanotubes are drawing wide attention of research communities and several industries due to their versatile capabilities covering mechanical and other multi-physical properties. However, owing to extreme operating conditions of the synthesis process of these nanostructures, they are often imposed with certain inevitable structural deformities such as single vacancy and nanopore defects. These random irregularities limit the intended functionalities of carbon nanotubes severely. In this article, we investigate the mechanical behaviour of double-wall carbon nanotubes (DWCNT) under the influence of arbitrarily distributed single vacancy and nanopore defects in the outer wall, inner wall, and both the walls. Large-scale molecular simulations reveal that the nanopore defects have more detrimental effects on the mechanical behaviour of DWCNTs, while the defects in the inner wall of DWCNTs make the nanostructures more vulnerable to withstand high longitudinal deformation. From a different perspective, to exploit the mechanics of damage for achieving defect-induced shape modulation and region-wise deformation control, we have further explored the localized longitudinal and transverse spatial effects of DWCNT by designing the defects for their regional distribution. The comprehensive numerical results of the present study would lead to the characterization of the critical mechanical properties of DWCNTs under the presence of inevitable intrinsic defects along with the aspect of defect-induced spatial modulation of shapes for prospective applications in a range of nanoelectromechanical systems and devices.

Detection of peri-implant bone defects using cone-beam computed tomography and digital periapical radiography with parallel and oblique projection

  • Saberi, Bardia Vadiati;Khosravifard, Negar;Ghandari, Farnaz;Hadinezhad, Arash
    • Imaging Science in Dentistry
    • /
    • v.49 no.4
    • /
    • pp.265-272
    • /
    • 2019
  • Purpose: To compare the diagnostic accuracy of cone-beam computed tomography (CBCT) with that of parallel(PPA) and oblique projected periapical(OPA) radiography for the detection of different types of peri-implant bone defects. Materials and Methods: Forty implants inserted into bovine rib blocks were used. Thirty had standardized bone defects(10 each of angular, fenestration, and dehiscence defects), and 10 were defect-free controls. CBCT, PPA, and OPA images of the samples were acquired. The images were evaluated twice by each of 2 blinded observers regarding the presence or absence and the type of the defects. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were determined for each radiographic technique. The 3 modalities were compared using the Fisher exact and chi-square tests, with P<0.05 considered as statistical significance. Results: High inter-examiner reliability was observed for the 3 techniques. Angular defects were detected with high sensitivity and specificity by all 3 modalities. CBCT and OPA showed similar AUC and sensitivity in the detection of fenestration defects. In the identification of dehiscence defects, CBCT showed the highest sensitivity, followed by OPA and PPA, respectively. CBCT and OPA had a significantly greater ability than PPA to detect fenestration and dehiscence defects(P<0.05). Conclusion: The application of OPA radiography in addition to routine PPA imaging as a radiographic follow-up method for dental implantation greatly enhances the visualization of fenestration and dehiscence defects. CBCT properly depicted all defect types studied, but it involves a relatively high dose of radiation and cost.

A Method to Establish Severity Weight of Defect Factors for Application Software using ANP (ANP 모형을 이용한 응용 소프트웨어 결함요소에 대한 중요도 가중치 설정 기법)

  • Huh, SangMoo;Kim, WooJe
    • Journal of KIISE
    • /
    • v.42 no.11
    • /
    • pp.1349-1360
    • /
    • 2015
  • In order to improve software quality, it is necessary to efficiently and effectively remove software defects in source codes. In the development field, defects are removed according to removal ratio or severity of defects. There are several studies on the removal of defects based on software quality attributes, and several other studies have been done to improve the software quality using classification of the severity of defects, when working on projects. These studies have thus far been insufficient in terms of identifying if there exists relationships between defects or whether any type of defect is more important than others. Therefore, in this study, we collected various types of software defects, standards organization, companies, and researchers. We modeled the defects types using an ANP model, and developed the weighted severities of the defects types, with respect to the general application software, using the ANP model. When general application software is developed, we will be able to use the weight for each severity of defect type, and we expect to be able to remove defects efficiently and effectively.

RECONSTRUCTION OF MIDFACIAL AND PALATAL DEFECTS AFTER MAXILLECTOMY (상악골 절제술후 발생한 중앙부및 구개 결손부의 재건)

  • Kim, Hoon;Choi, Mi-Suk;Choi, Sung-Won;Kim, Ho-Kyeom;Kim, Sung-Moon;Rim, Jae-Suk;Kwon, Jong-Jin
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.18 no.1
    • /
    • pp.1-16
    • /
    • 1996
  • There are various defects caused by trauma or resection of maignant tumor in the orofacial region, which can be reconstructed with various regional and pararegional flaps. Among these defects, it is very difficult to reconstruct palatal and midfacial defects after maxillectomy and patients have problems in speaking and swallowing of food. Therefore it is very important for surgeons to reconstruct these defects functionally and esthetically and to return the patients to the normal social activity. These defects are usually obturated with prosthodontic appliances to assist the phonation and swallowing. But nowadays surgical reconstruction by various flaps was considered and performed for better rehabilitation. For this purpose the forehead flap, the nasolabial flap, the tongue flap, the sternocleidomastoideous flap, the temporal flap, the latissimus dorsi flap, the scapular flap etc. are used. We reconstructed small-sized plalatal defects with tongue flap, medium-sized palatal and maxillary defects after maxillectomy with temporal myofascial flap and large midfacial defects including eyeball exenteration with latissimus dorsi myocutaneous flaps. Here we are to report 5 cases of these flaps used for the reconstruction of palatal and midfacial defects and consider the versatility, reliability and limitation in use of these flaps.

  • PDF

Roughness and micro pit defects on surface of SUS 430 stainless steel strip in cold rolling process

  • Li, Changsheng;Zhu, Tao;Fu, Bo;Li, Youyuan
    • Advances in materials Research
    • /
    • v.4 no.4
    • /
    • pp.215-226
    • /
    • 2015
  • Experiment on roughness and micro pit defects of SUS 430 ferrite stainless steel was investigated in laboratory. The relation between roughness and glossiness with reduction in height, roll surface roughness, emulsion parameters was analyzed. The surface morphology of micro pit defects was observed by SEM, and the effects of micro pit defects on rolling reduction, roll surface roughness, emulsion parameters, lubrication oil in deformation zone and work roll diameter were discussed. With the increasing of reduction ratio strip surface roughness Ra(s), Rp(s) and Rv(s) were decreasing along rolling and width direction, the drop value in rolling direction was faster than that in width direction. The roughness and glossiness were obtained under emulsion concentration 3% and 6%, temperature $55^{\circ}C$ and $63^{\circ}C$, roll surface roughness $Ra(r)=0.5{\mu}m$, $Ra(r)=0.7{\mu}m$ and $Ra(r)=1.0{\mu}m$. The glossiness was declined rapidly when the micro defects ratio was above 23%. With the pass number increasing, the micro pit defects were reduced, uneven peak was decreased and gently along rolling direction. The micro pit defects were increased with the roll surface roughness increase. The defects ratio was declined with larger gradient at pass number 1 to 3, but gentle slope at pass number 4 to 5. When work roll diameter was small, bite angle was increasing, lubrication oil in micro pit of deformation zone was decreased, micro defects were decreased, and glossiness value on the surface of strip was increased.

BONE REGENERATION OF THE EXPERIMENTAL ENDODONTIC-PERIODONTIC COMBINED DEFECTS IN THE MANDIBLES OF THE DOGS (성견 하악의 치주-치근단 실험적 복합병소에서 골조직 재생에 관한 연구)

  • Kim, Jeong-Hye;Baek, Seung-Ho;Yoon, Soo-Han
    • Restorative Dentistry and Endodontics
    • /
    • v.24 no.2
    • /
    • pp.286-298
    • /
    • 1999
  • The endodontic-periodontic combined lesions have been difficult to get correct diagnosis and predictable treatment. This study was to make the experimental endodontic-periodontic combined defects in dogs for the study of the periodontal regeneration and to evaluate the efficacy of the enamel matrix protein and e-PTFE membrane in the experimental endodontic-periodontic combined defects. 5 mongrel dogs were used. The pulp chambers were opened and the plaque was inserted into the chambers to induce the periapical lesions on the mandibular second, third and fourth premolars of the dogs. 1 month later, the root canal treatments were done with gutta perch a and ZOE sealer. On the day of surgery, the periapical defects were standardized by trephine bur. The buccal dehiscence defects were made by the dental bur and bone chisels. The apicoectomy with retrofilling was done. The prepared roots were randomly selected for test and control groups. In the experimental groups, the enamel matrix derivative and e-PTFE membrane were used. Nothing was placed on the control group. Fluroscent labelling was used to evaluate the bone formation. After 4 and 12 weeks, the dogs were sacrificed and undecalcified sections were prepared and stained with toluidine blue. Those histologic sections were examined by fluorescent microscopy and light microscopy. The results were as follows. 1. In the control group, new bone was formed in the periapical defects and scarcely in the buccal dehiscence defects. New cementum was not detected at 4 and 12 weeks. 2. In the experimental groups, new bone, new cementum and periodontal ligament were found in the periapical and buccal dehiscence defects. The relative amount and the quality of the new bone, new cementum and periodontal ligament tissue that had formed on the experimental groups were superior to those of the control group. 3. The current observation implicated that e-PTFE membrane and enamel matrix protein could be the effective tools for the guided tissue regeneration of the endo-perio combined defects.

  • PDF

Proximally based sural artery flap for the reconstruction of soft tissue defects around the knee and proximal third of the leg in India: a clinical study

  • Palukuri Lakshmi;Sreedharala Srinivas;Dharmapuri Madhulika;Sanujit Pawde;Ajo Sebastian;Swathi Sankar;Sandeep Reddy Chintha
    • Journal of Trauma and Injury
    • /
    • v.36 no.4
    • /
    • pp.369-375
    • /
    • 2023
  • Purpose: The reconstruction of defects around the knee and the proximal third of the leg necessitates thin, pliable skin with a stable and sensate soft tissue cover. This study analyzed the use of a proximally based sural artery flap for the coverage of such defects. Methods: This prospective clinical interventional study involved 10 patients who had soft tissue defects over the knee and the proximal third of the leg. These patients underwent reconstruction with a proximally based sural artery flap. The study analyzed various factors including age, sex, etiology, location and presentation of the defect, defect dimensions, flap particulars, postoperative complications, and follow-up. Results: There were 10 cases, all of which involved men aged 20 to 65 years. The most common cause of injury was trauma resulting from road traffic accidents. The majority of defects were found in the proximal third of the leg, particularly on the anterolateral aspect. Defect dimensions varied from 6×3 to 15×13 cm2, and extensive defects as large as 16 cm×14 cm could be covered using this flap. The size of the flaps ranged from 7×4 to 16×14 cm2, and the pedicle length was 10 to 15 cm. In all cases, donor site closure was achieved with split skin grafting. This flap consistently provided a thin, pliable, stable, and durable soft tissue cover over the defect with no functional deficit and minimal donor site morbidity. Complications, including distal flap necrosis and donor site graft loss, were observed in two cases. Conclusions: The proximally based sural fasciocutaneous flap serves as the primary method for reconstructing medium to large soft tissue defects around the knee and the proximal third of the leg. This technique offers thin, reliable, sensate, and stable soft tissue coverage, and can cover larger defects with minimal complications.

The Detection of Defects in Ferromagnetic Materials Using Magneto-Optical Sensor (자기광학센서를 이용한 강자성체 결함 탐상)

  • Kim, Hoon
    • Journal of Power System Engineering
    • /
    • v.8 no.3
    • /
    • pp.52-57
    • /
    • 2004
  • A new non-destructive inspection technique has been developed. One characteristic of the technique is that defects are visualized by laser ray. Magnetic domains and domain walls of a magneto-optical sensor(MO sensor) are varied by the magnetic flux leaked by defects, and the variations are observed by the reflected light of the laser ray. The information of defect can remotely be inspected by this technique in a real time. This paper describes the results estimated on the 2-dimensional surface defects and opposite-side defects in a ferromagnetic material and the natural surface defect in a clutch disk wheel. The light region of a visible image and the magnitude of a reflected light increases as the input current of the magnetizer increases. The natural surface defect, that has not the width of crack's open mouth, can be also visualized like as 2-dimensional artificial defects.

  • PDF