scholarly journals Biomechanical Analysis of Various Reconstructive Methods for the Mandibular Body and Ramus Defect Using a Free Vascularized Fibula Flap

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xian Li ◽  
Chao Jiang ◽  
Hui Gao ◽  
Chunjuan Wang ◽  
Chao Wang ◽  
...  

Several different methods exist for reconstructing the mandibular body and ramus defect with the use of a free vascularized fibula flap, but none have adequately addressed the long-term mechanical stability and osseointegration. The aim of this study is to compare the biomechanics of different surgical methods and to investigate the best approach for reconstructing the mandibular body and ramus defect. Five finite element models based on different reconstructive methods were simulated. Stress, strain, and displacement of connective bone sections were calculated for five models and compared. The models were printed using a 3D printer, and stiffness was measured using an electromechanical universal testing machine. The postoperative follow-up cone beam computed tomography (CBCT) was taken at different time points to analyze bone mineral density of connective bone sections. The results showed that the “double up” (DU) model was the most efficient for reconstructing a mandibular body and ramus defect by comparing the mechanical distribution of three sections under vertical and inclined loading conditions of 100 N. The stiffness detection showed that stiffness in the DU and “double down” (DD) models was higher compared with the “single up” (SU), “single down” (SD), and “distraction osteogenesis” (DO) models. We used the DU model for the surgery, and postoperative follow-up CBCT showed that bone mineral density of each fibular connective section increased gradually with time, plateauing at 12 weeks. We conclude that a free vascularized fibula flap of the DU type was the best approach for the reconstruction of the mandibular body and ramus defect. Preoperative finite element analysis and stiffness testing were shown to be very useful for maxillofacial reconstruction.

2014 ◽  
Author(s):  
Mingo Dominguez Maria Luisa de ◽  
Sonsoles Guadalix Iglesias ◽  
Maria Begona Lopez Alvarez ◽  
Guillermo Martinez Diaz-Guerra ◽  
Federico Hawkins Carranza

Author(s):  
Gabriella Martino ◽  
Federica Bellone ◽  
Carmelo M. Vicario ◽  
Agostino Gaudio ◽  
Andrea Caputo ◽  
...  

Clinical psychological factors may predict medical diseases. Anxiety level has been associated with osteoporosis, but its role on bone mineral density (BMD) change is still unknown. This study aimed to investigate the association between anxiety levels and both adherence and treatment response to oral bisphosphonates (BPs) in postmenopausal osteoporosis. BMD and anxiety levels were evaluated trough dual-energy X-ray absorptiometry and the Hamilton Anxiety Rating Scale (HAM-A), respectively. Participants received weekly medication with alendronate or risedronate and were grouped according to the HAM-A scores into tertiles (HAM-A 3 > HAM-A 2 > HAM-A 1). After 24 months, BMD changes were different among the HAM-A tertiles. The median lumbar BMD change was significantly greater in both the HAM-A 2 and HAM-A 3 in comparison with the HAM-A 1. The same trend was observed for femoral BMD change. Adherence to BPs was >75% in 68% of patients in the HAM-A 1, 79% of patients in the HAM-A 2, and 89% of patients in the HAM-A 3 (p = 0.0014). After correcting for age, body mass index, depressive symptoms, and the 10-yr. probability of osteoporotic fractures, anxiety levels independently predicted lumbar BMD change (β = 0.3417, SE 0.145, p = 0.02). In conclusion, women with higher anxiety levels reported greater BMD improvement, highlighting that anxiety was associated with adherence and response to osteoporosis medical treatment, although further research on this topic is needed.


2008 ◽  
Vol 19 (6) ◽  
pp. 839-847 ◽  
Author(s):  
A. C. Heijckmann ◽  
M. Drent ◽  
B. Dumitrescu ◽  
J. De Vries ◽  
A. C. Nieuwenhuijzen Kruseman ◽  
...  

2020 ◽  
Vol 138 ◽  
pp. S81
Author(s):  
C. Blomqvist ◽  
L. Vehmanen ◽  
H. Sievänen ◽  
P. Kellokumpu-Lehtinen ◽  
R. Nikander ◽  
...  

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Zewei Shen ◽  
◽  
Canqing Yu ◽  
Yu Guo ◽  
Zheng Bian ◽  
...  

Abstract Summary In a Chinese population from both urban and rural areas, weight loss of ≥ 5 kg from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life. Introduction This study investigates the association of the long-term weight loss from young adulthood through the middle ages with the subsequent 10-year risk of hospitalized fracture and calcaneus bone mineral density (BMD). Methods China Kadoorie Biobank (CKB) was established during 2004–2008 in ten areas across China. Weight at age 25 years was self-reported at baseline, and weight at baseline and resurvey was measured by the calibrated equipment. Outcomes were hospitalized fracture during follow-up and calcaneus BMD measured at resurvey. Analysis for fracture risk included 411,812 participants who were free of fracture in the last 5 years before baseline, cancer, or stroke at any time before baseline. Analysis for BMD included 21,453 participants who participated in the resurvey of 2013–2014 with the same exclusion criteria as above. Results The mean age was 50.8 at baseline and 58.4 at resurvey. Median weight change from age 25 to baseline was 4.4 kg, with 20.7% losing weight and 58.5% gaining weight. During a median follow-up of 10.1 years, we documented 13,065 cases of first diagnosed fracture hospitalizations, including 1222 hip fracture. Compared with participants whose weight was stable (± 2.4 kg), the adjusted hazard ratios (95% CIs) for those with weight loss of ≥ 5.0 kg from age 25 to baseline was 1.39 (1.17 to 1.66) for hip fracture. Weight loss was not associated with fracture risk at other sites. Those with weight loss from age 25 to resurvey had the lowest BMD measures, with β (95% CIs) of − 4.52 (− 5.08 to − 3.96) for broadband ultrasound attenuation (BUA), − 4.83 (− 6.98, − 2.67) for speed of sound (SOS), and − 4.36 (− 5.22, − 3.49) for stiffness index (SI). Conclusions Weight loss from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life.


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