1.Biomechanical study on restorative methods of unilateral maxilla based on finite element analysis.
Jiayi SUN ; Peng XU ; Lizhen WANG ; Xufeng NIU ; Yubo FAN
Journal of Biomedical Engineering 2014;31(3):590-605
This paper is to report our study in which the differences between prosthetic restoration and surgical reconstruction using traditional clasp retention technology were analyzed based on three-dimensional finite element methods in our laboratory. Firstly, the maxillary unilateral defect model was developed using medical image processing software MIMICS. Secondly, the prosthesis was generated by mirroring technology. The clasp was designed according to the methods raised by Aramany. Then, the stress distribution of maxilla was calculated by simulating occlusion. According to the results, after osseointegration of surgical reconstruction, stresses of unaffected abutments were reduced significantly, and less stress of junction occurred near zygoma of affected side, which were all less than stresses of prosthesis restoration. Thus, removing the clasp of surgical reconstruction increased the stresses of unaffected abutments. The stress trends of maxillary components were different between prosthetic restoration and surgical reconstruction. Surgical reconstruction is better than prosthesis restoration in protection of the abutments. Clasp can alleviate the occlusal burden of maxilla. Varieties of retentive technologies can be considered in prosthesis restoration. The surgical reconstruction is more conducive to rehabilitate unilateral maxilla biomechanically in clinic.
Biomechanical Phenomena
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Finite Element Analysis
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Humans
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Image Processing, Computer-Assisted
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Mandibular Reconstruction
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methods
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Maxilla
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surgery
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Maxillofacial Prosthesis
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Osseointegration
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Zygoma
2.Advance in research of osteoblast adhesion to bioactive materials.
Xufeng NIU ; Yanfeng LUO ; Jun PAN ; Yuanliang WANG
Journal of Biomedical Engineering 2005;22(4):848-852
In the research field of bone tissue engineering, the interaction of osteoblast and substrate is pivotal and the adhesion of osteoblast to biomaterials is the basic condition. Firstly, osteoblast must adhere to biomaterials, then it can migrate, proliferate and differentiate. This paper introduces the proteins relating to the adhesion of osteoblast and the influences of relating surface character and modification of biomaterials on the adhesion ability of osteoblast. These could serve as basic data and useful reference for the development of bone tissue engineering and tissue engineering scaffold materials.
Biocompatible Materials
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chemistry
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Bone Regeneration
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Cell Adhesion
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Cell Differentiation
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Cell Proliferation
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Humans
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Osteoblasts
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cytology
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Surface Properties
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Tissue Engineering
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methods
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Tissue Scaffolds
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chemistry
3.Effect of overload environment on IGF-1 expression of osteoblasts.
Juanfang SHANG ; Liling TANG ; Xufeng NIU ; Yuanliang WANG
Journal of Biomedical Engineering 2006;23(6):1363-1366
In the study of the relationship between cells overloading and the formation, regeneration and growth of bone, the text discussed osteoblasts express IGF-1 variation under overloading environment. The research of overloading on cellular level may elucidate the mechanical effect on the formation, regeneration and growth of bone and the mechanism of cell response in bone.
Animals
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Humans
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Insulin-Like Growth Factor I
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biosynthesis
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genetics
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Osteoblasts
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cytology
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metabolism
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Osteogenesis
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RNA, Messenger
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biosynthesis
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genetics
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Stress, Mechanical
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Weight-Bearing
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physiology
4.Efficacy of moderate dose bromocriptine by one-off oral administration in patients with non-acute prolactin type pituitary adenoma
Lin WANG ; Shiying LING ; Cuizhu MEI ; Ju ZHANG ; Xufeng CHENG ; Li JIA ; Chaoshi NIU ; Xianming FU
Chinese Journal of Neuromedicine 2019;18(6):589-592
Objective To explore the efficacy of moderate dose bromocriptine by one-off oral administration in treatment of patients with non-acute prolactin (PRL) type pituitary adenoma.Methods Forty-three patients with definite diagnosis of non-acute prolactin type pituitary adenoma,admitted to our hospital from January 2016 to December 2017,were chosen in our study.All patients were administrated with 5 mg bromocriptine at 18 pm;the serum PRL levels were examined at 2,3 and 12 h after bromocriptine administration.The curative effects of these patients were judged by decline rate of PRL,and the curative effects of patients with different genders,different initial PRL levels and different ages were compared.Results In these 43 patients,bromocriptine showed excellent effect in 20 patients,obvious effect in 18 and invalid effect in 5.There were statistically significant differences in the efficacy of bromocriptine between different genders (P<0.05).There were statistically significant differences in efficacy of patients with different genders after taking bromocriptine (P<0.05).The female patients had obviously higher rate of obvious effect than the male patients.Patients with different initial PRL values had statistically significant differences in efficacy after taking bromocriptine (P<0.05).Patients with PRL initial value of 40-200 ng/mL had significantly higher rate of obvious effect than patients with PRL initial value of >200 ng/mL.There was no significant difference in efficacy between patients < 45 years old and patients>45 years old (P>0.05).Conclusion The treatment ofhyperprolactin caused by prolactin type pituitary adenoma with moderate dose bromocriptine by one-off oral administration is effective;female patients have obviously better effect than male patients;and for patients with initial prolactin>200 ng/mL,the effect is better.
5.Biomechanical Environment Regulates Biomimetic Mineralization of Bone Matrix
Chunyang MA ; Tianming DU ; Xufeng NIU ; Yubo FAN
Journal of Medical Biomechanics 2022;37(2):E200-E210
Bone defects have always been an important cause of threat to human health, and artificial biomimetic bone repair replacement materials are currently one of the most effective and feasible solution approaches to treat bone damage. To develop artificial bone biomimetic materials, an in vitro biomimetic mineralization system must be constructed first to study in vitro biomimetic mineralization mechanism of natural bone matrix. Collagen is a template for mineralization, and its properties such as crosslinking degree, diameter, osmotic pressure, and surface charge can all directly affect mineralization progress. The biochemical and mechanical environments in which mineralization occurs are also quite distinct in their effects on mineralization process, particularly noncollagenous proteins and fluid shear stress (FSS). FSS is considered to be the main mechanical stimulation of bone tissues in micro-environment, which is of great significance to bone growth, repair and health maintenance. FSS at different levels and loading regimes has significant effects on transformation of amorphous calcium phosphate to bone apatite, self-assembly and directional alignment of collagen fibrils, and formation of hierarchical intrafibrillar mineralization. In this paper, the factors affecting collagen mineralization and their mechanism were summarized, with focus on regulation of FSS on collagen mineralization, and development direction in future was also prospected.