• Title/Summary/Keyword: Bone plates

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A Study on Detection Performance Comparison of Bone Plates Using Parallel Convolution Neural Networks (병렬형 합성곱 신경망을 이용한 골절합용 판의 탐지 성능 비교에 관한 연구)

  • Lee, Song Yeon;Huh, Yong Jeong
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.3
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    • pp.63-68
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    • 2022
  • In this study, we produced defect detection models using parallel convolution neural networks. If convolution neural networks are constructed parallel type, the model's detection accuracy will increase and detection time will decrease. We produced parallel-type defect detection models using 4 types of convolutional algorithms. The performance of models was evaluated using evaluation indicators. The model's performance is detection accuracy and detection time. We compared the performance of each parallel model. The detection accuracy of the model using AlexNet is 97 % and the detection time is 0.3 seconds. We confirmed that when AlexNet algorithm is constructed parallel type, the model has the highest performance.

A PHOTOELASTIC ANALYSIS OF THE EFFECT OF ORTHOPEDIC FORCES ON THE CRANIOFACIAL COMPLEX UTILIZING THE THREE KINDS OF THE HEAD GEAR (각종의 HEAD GEAR를 사용한 정형력이 두개안면 골에 미치는 영향에 대한 광탄성적 연구)

  • Kim, Kwang-Ho
    • The korean journal of orthodontics
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    • v.16 no.1
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    • pp.71-84
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    • 1986
  • The purpose of this study was to analyze the effect of orthopedic forces on the craniofacial complex utilizing the three kinds of the head gear. (high pull head gear, straight pull head gear, cervical pull head gear) For this study, the teeth and alveolar bone and palate were reproduced from birefringent materials and other parts of craniofacial complex were coated with birefringent material on the model. The effect of orthopedic forces on the craniofacial complex was analyzed by photoelastic method using transmission polariscope and reflection polariscope. The results were as follows. 1. The cervical pull head gear had the greatest tipping effect on the maxillary molars and high pull head gear had the least tipping effect. 2. In areas stressed, the cervical pull head gear stressed the greatest degree. 3. Only cervical pull head gear produced stress at the zygomaticofrontal suture and the posterior region of palate. 4. The straight pull head gear and high pull head gear produced stress at just inferior to the anterior nasal spine. 5. The cervical pull head gear and straight pull head gear produced tensile stress at the fronto-maxillary suture. 6. The pterygoid plates of the sphenoid bone, the zygomatic arches, the junction of the maxilla with the lacrimal and ethmoid bone, and the maxillary molars were affected by three types of head gear.

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The effects of circadian disturbances induced by night shifts on the mouse peripheral tissues

  • Seo, Dong-Hyun;Kim, Han-Sung;Ko, Chang-Yong;Schreiber, Jurgen;Jang, Yeong-Su;Bae, Kiho
    • Animal cells and systems
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    • v.16 no.5
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    • pp.357-365
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    • 2012
  • We have examined the effect of circadian disturbances induced by night shifts (NSs) on the phenotypes of the tibiae and abdominal adipose tissues (ADTs) in a mouse model by using in vivo micro-computed tomography (micro-CT). We found that the volumes of total and visceral ADTs in the night-shifted group of mice were significantly larger (69 and 92%, respectively) than those in the control. The mean polar moment of inertia, cross-sectional thickness, and bone mineral density of the cortical bone in the night-shifted group of mice were less (13, 5, and 3%, respectively) than those in the control. Moreover, the volume and the thickness of growth plates (GPs) of the tibiae in the night-shifted mice were significantly smaller (22 and 20%, respectively) than those in the control. Taken together, our results indicate that disturbances in the mouse circadian rhythms induced by NSs affect the morphological characteristics of cortical bone, the volume and the thickness of GPs, and the volume of ADTs.

Evaluation of the Effect of Oriental Medicinal Herbs with Growth Factors on Bone Development using the SD Strain Rat Model in the Growth Period (뼈 발달에 관한 성장인자를 가진 한약재가 성장기 흰쥐 동물모델에 미치는 영향)

  • Sim, Jae-Won;Ahn, Hee-Young;Sim, So-Yeon;Kim, Hee-Young;Cho, Yong-Ju;Cho, Young-Su
    • Journal of Life Science
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    • v.29 no.5
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    • pp.614-620
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    • 2019
  • The purpose of this study was to examine the growth plate, femoral bone length, bone mineral density, and blood composition in various experimental animals fed with oriental medicinal herbs containing growth factors. First, the lengths of the bone growth plates of the positive control (PC) group (fed with Astragalus membranaceus) and the Gh-199 and Sh-188 groups were increased when compared to group N. The Gh-199 group showed a greater increase in bone growth when compared with the PC group. In terms of the femoral bone length and bone mineral density, the effect of both Gh-199 and Sh-188 powders were as good as those of the PC group, and the Gh-199 powder showed a positive effect. Conversely, in the PC group, unlike the Gh-199 and Sh-188 groups, the aspartate aminotransferase(AST) and alanine aminotransferase(ALT) activities in the blood were increased, indicating that A. membranaceus is toxic to the body. Both the PC and Sh-188 groups also showed higher insulin-like growth factor-1(IGF-1) activity when compared with the Gh-199 group. Overall, the bone growth plate, femoral bone length, and bone mineral density measurements, and the blood analysis showed positive results in the group treated with Gh-199, and no specific toxicity of the herbal medicine in the body was evident.

The Analysis of the Treatment Outcomes of Proximal Humeral Fractures with Locking Plates

  • Lee, Kwang-Won;Hwang, Yoon-Sub;Kim, Choon-Myeon;Yang, Dae-Suk;Park, Tae-Soo
    • Clinics in Shoulder and Elbow
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    • v.17 no.1
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    • pp.10-17
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    • 2014
  • Background: The aim of this study was to assess the clinical outcomes after treatment of proximal humeral fractures with locking plates, and to determine which factors influence the clinical and radiological outcomes. Methods: Fifty six patients who were treated with locking plates for proximal humeral fractures and had been followed for more than 1 year were enrolled in this study. We performed functional evaluation using the Constant score and analyzed radiographic results. The following factors that may potentially influence the clinical outcomes were assessed: age, gender, type of fracture, presence of medial metaphyseal comminution, bone mineral density, anatomical reduction, restoration of medial mechanical support, and postoperative complications. Results: The mean Constant score was 70.1 points at the final follow-up. Female gender, 4-part fractures, AO type-C fractures, and fractures with medial metaphyseal comminution were associated with a poor clinical outcome. On the other hand, restoration of medial mechanical support and accurate anatomical reduction had a positive influence on clinical outcomes. Postoperative complications resulted in 3 patients (intra-articular screw perforation: 1 patient, varus deformity with screw loosening: 1 patient, nonunion: 1 patient). Conclusions: When treating proximal humeral fractures with locking plate fixation, following factors: a female gender, Neer type 4-part fracture, AO type C fracture, and medial metaphyseal comminution are important risk factors that surgeons should take into consideration. Factors that contribute to better clinical outcomes of operative treatment for humeral fractures are accurate anatomical reduction and restoration of medial mechanical support.

Anatomic fit of precontoured extra-articular distal humeral locking plates: a cadaveric study

  • Lim, Joon-Ryul;Yoon, Tae-Hwan;Lee, Hwan-Mo;Chun, Yong-Min
    • Clinics in Shoulder and Elbow
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    • v.24 no.2
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    • pp.66-71
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    • 2021
  • Background: Extra-articular distal humerus locking plates (EADHPs) are precontoured anatomical plates widely used to repair distal humeral extra-articular diaphyseal fractures. However, EADHPs frequently cause distal protrusion and resulting skin discomfort. The purpose of this study was to predict the occurrence of anatomic fit mismatch. We hypothesized that the smaller the humerus size, the greater the anatomic fit mismatch with EADHP. Methods: Twenty humeri were analyzed in this study. Humeral length and distal humeral width were used as parameters of humeral size. Plate protrusion was measured between the EADHP distal tip and the distal humerus. We set the level of unacceptable EADHP anatomic fit mismatch as ≥10 mm plate protrusion. Results: A significant negative linear correlation was also confirmed between humeral size and plate protrusion, with a coefficient of determination of 0.477 for humeral length and 0.814 for distal humeral width. The cutoff value of humeral length to avoid ≥10 mm plate protrusion was 293.6 mm (sensitivity, 88.9%; specificity, 81.8%) and for distal humeral width was 60.5 mm (sensitivity, 100%; specificity, 81.8%). Conclusions: Anatomic fit mismatch in distal humeral fractures after EADHP fixation has a negative linear correlation with humeral length and distal humeral width. For patients with a distal humeral width <60.5 mm, ≥10 mm plate protrusion will occur when an EADHP is used, and an alternative implant or approach should be considered.

THE LONG-TERM CONSERVATIVE DRAINAGE CARE OF EXTENSIVE OSTEOMYELITIS ASSOCIATED WITH MANDIBULAR COMPOUND FRACTURE : REPORT OF A CASE (장기간의 보존적 배농술로 치료된 하악 복합골절 관련 광범위 골수염 치험 : 증례보고)

  • Kim, Ha-Rang;Yoo, Jae-Ha;Choi, Byung-Ho;Sul, Sung-Han;Mo, Dong-Yub;Lee, Chun-Ui
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.6
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    • pp.544-549
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    • 2009
  • Failure to use effective methods of reduction, fixation and immobilization may lead to osteomyelitis with the exposed necrotic bone, as the overzealous use of transosseous wires & plates that devascularizes bone segments in the compound comminuted fractures of mandible. Once osteomyelitis secondary to fractures has become established, intermaxillary fixation should be instituted as early as possible. Fixation enhances patient comfort and hinders ingress of microorganisms and debris by movement of bone fragments. Teeth and foreign materials that are in the line of fracture should be removed and initial debridement performed at the earliest possible time. Grossly necrotic bone should be excised as early as possible ; no attempt should be made to create soft tissue flaps to achieve closure over exposed bone. The key to treatment of chronic osteomyelitis of the mandible is adequate and prolonged soft tissue drainage. If good soft tissue drainage is provided over a long period, sequestration of infected bone followed by regeneration or fibrous tissue replacement will occur so that appearance and function are not seriously altered. Localization and sequestration of infected mandible are far better performed by natural mechanism of homeostasis than by cutting across involved bone with a cosmetic or functional defect. As natural host defenses and conservative therapy begin to be effective, the process may become chronic, inflammation regresses, granulation tissue is formed, and new blood vessels cause lysis of bone, thus separating fragments of necrotic bone(sequestra) from viable bone. The sequestra may be isolated by a bed of granulation tissue, encased in a sheath of new bone(involucrum), and removed easily with pincettes. This is a case report of the long-term conservative drainage care in osteomyelitis associated with mandibular fractures.

Comparison between different cone-beam computed tomography devices in the detection of mechanically simulated peri-implant bone defects

  • Kim, Jun Ho;Abdala-Junior, Reinaldo;Munhoz, Luciana;Cortes, Arthur Rodriguez Gonzalez;Watanabe, Plauto Christopher Aranha;Costa, Claudio;Arita, Emiko Saito
    • Imaging Science in Dentistry
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    • v.50 no.2
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    • pp.133-139
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    • 2020
  • Purpose: This study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles. Materials and Methods: Twenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient. Results: High intraobserver and interobserver agreement was found (P<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts. Conclusion: Within the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.

A comparison of fixation methods using three-dimensional finite element analysis following anterior segmental osteotomy

  • Yun, Kyoung In;Park, Min-Kyu;Park, Myung-Kyun;Park, Je Uk
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.38 no.6
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    • pp.332-336
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    • 2012
  • Objectives: This study sought to evaluate fixation methods and determine the best method for the postoperative stabilization of maxillary osteotomy. For our analysis we performed a three-dimensional finite element analysis of stress distribution on the plate, screw, and surrounding bone, as well as displacement onto the plate. Materials and Methods: We generated a model using synthetic skull scan data; an initital surface model was changed to a solid model using software. Modified anterior segmental osteotomy (using Park's method) was made using the program, and four different types of fixation methods were used. An anterior load of 100 N was applied on the palatal surface of two central incisors. Results: The Type 1 (L-shaped) fixation method gave stresses of 187.8 MPa at the plate, 45.8 MPa at the screw, and 15.4 MPa at the bone around the plate. The Type 2 (I-shaped) fixation method gave stresses of 186.6 MPa at the plate, 75.7 MPa at the screw, and 13.8 MPa at the bone around the plate. The Type 3 (inverted L-shaped) fixation method gave stresses of 28.6 MPa at the plate, 29.9 MPa at the screw, and 15.3 MPa at the bone around the plate. The Type 4 (I-shaped) fixation method gave stresses of 34.8 MPa at the plate, 36.9 MPa at the screw, and 14.9 MPa at the bone around the plate. The deflection of the plates for the four fixation methods was 0.014 mm, 0.022 mm, 0.017 mm, and 0.018 mm, respectively. Conclusion: The Type 3 (inverted L-shaped) fixation method offers more stability than the other fixation methods. We therefore recommend this method for the postoperative stabilization of maxillary osteotomy.

The Clinical Usefulness of Ultrasound-Aided Fixation Using an Absorbable Plate System in Patients with Zygomatico-Maxillary Fracture

  • Lee, Jong Hun;Park, Jun Hyung
    • Archives of Plastic Surgery
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    • v.40 no.4
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    • pp.330-334
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    • 2013
  • Background Ultrasound-aided fixation is a recently developed alternative method of treatment of zygomatico-maxillary (ZM) fracture, and it can resolve the problems of excessive torsion force and subsequent fractures of screws. We conducted this study to evaluate the clinical usefulness of ultrasound-aided fixation as compared with the conventional fixation method using a drill and an expander in patients with ZM fracture. Methods We conducted a retrospective study in 35 patients with ZM fracture who had been treated at our hospital during a period ranging from March of 2008 to December of 2010. We divided them into two groups: an ultrasound-aided fixation group, comprising 13 patients who underwent ultrasound-aided fixation (SonicWeld Rx, KLS Martin), and a conventional group, comprising 22 patients who underwent conventional fixation (Biosorb FX, Linvatec Biomaterials Ltd.). We compared such variables as sex, direction, age at operation, follow-up period, operation duration, number of fixed holes, and time to discharge between the two groups. Results The ultrasound-aided fixation reduced the operation duration by about 30 minutes as compared with that of conventional fixation. There was no significant difference in follow-up period, number of fixed holes, or time to discharge between the two groups. Furthermore, there were no complications in either group. Conclusions The ultrasound-aided fixation of fractured ZM bone using an absorbable implant system is safe and effective in promptly reducing the bone fracture and providing satisfactory cosmetic outcomes over time.