Effects of Mechanical Stimuli on Adaptive Remodeling of Condylar Cartilage

2009 ◽  
Vol 88 (5) ◽  
pp. 466-470 ◽  
Author(s):  
D. Sriram ◽  
A. Jones ◽  
I. Alatli-Burt ◽  
M.A. Darendeliler
Keyword(s):  
High Frequency ◽  
Mechanical Vibration ◽  
Mechanical Stimuli ◽  
Micro Computed Tomography ◽  
Condylar Cartilage ◽  
Endochondral Bone ◽  
Hypertrophic Cartilage ◽  
C3h Mice ◽  
Experimental Group ◽  
Low Magnitude

Trabecular bone has been shown to be responsive to low-magnitude, high-frequency mechanical stimuli. This study aimed to assess the effects of these stimuli on condylar cartilage and its endochondral bone. Forty female 12-week-old C3H mice were divided into 3 groups: baseline control (killed at day 0), sham (killed at day 28 without exposure to mechanical stimuli), and experimental (killed following 28 days of exposure to mechanical stimuli). The experimental group was subjected to mechanical vibration of 30 Hz, for 20 minutes per day, 5 days per week, for 28 days. The specimens were analyzed by micro-computed tomography. The experimental group demonstrated a significant decrease in the volume of condylar cartilage and also a significant increase in bone histomorphometric parameters. The results suggest that the low-magnitude, high-frequency mechanical stimuli enhance adaptive remodeling of condylar cartilage, evidenced by the advent of endochondral bone replacing the hypertrophic cartilage.

Proteomics of osteoporosis in ovariectomized rats after low-magnitude and high-frequency mechanical vibration

Bone ◽  
2010 ◽  
Vol 47 ◽  
pp. S411 ◽  
Author(s):  
Renshi Ma ◽  
Yuxian Yan ◽  
Xu Huang ◽  
Dong Zhu ◽  
Xizheng Zhang
Keyword(s):  
High Frequency ◽  
Mechanical Vibration ◽  
Ovariectomized Rats ◽  
Low Magnitude

Effect of Low Magnitude and High Frequency Mechanical Stimuli on Defects Healing in Cranial Bones

2008 ◽  
Vol 66 (6) ◽  
pp. 1104-1111 ◽  
Author(s):  
Haitham Omar ◽  
Gang Shen ◽  
Allan S. Jones ◽  
Hans Zoellner ◽  
Peter Petocz ◽  
...  
Keyword(s):  
High Frequency ◽  
Mechanical Stimuli ◽  
Low Magnitude

Inhibition of osteopenia by low magnitude, high-frequency mechanical stimuli

2001 ◽  
Vol 6 (16) ◽  
pp. 848-858 ◽  
Author(s):  
Clinton T Rubin ◽  
Dirk W Sommerfeldt ◽  
Stefan Judex ◽  
Yi-Xian Qin
Keyword(s):  
High Frequency ◽  
Mechanical Stimuli ◽  
Low Magnitude

Parathyroid hormone promotes cartilage healing after free reduction of mandibular condylar fractures by upregulating Sox9

2021 ◽  
pp. 153537022110271
Author(s):  
Yuanyuan Jia ◽  
Liuqin Xie ◽  
Zhenglong Tang ◽  
Dongxiang Wang ◽  
Yun Hu ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Internal Fixation ◽  
Early Stage ◽  
Rabbit Model ◽  
Mandibular Condyle ◽  
Fracture Site ◽  
Control Group ◽  
Condylar Cartilage ◽  
Cartilage Healing ◽  
Experimental Group

After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical outcome. Parathyroid hormone (PTH) can promote the bone formation and mineralization of mandibular fracture, but its effects on cartilage healing after the free reduction and internal fixation of high fractures of the mandibular condyle are unknown. In this study, a rabbit model of free reduction and internal fixation of high fractures of the mandibular condyle was established, and the effects and mechanisms of PTH on condylar cartilage healing were explored. Forty-eight specific-pathogen-free (SPF) grade rabbits were randomly divided into two groups. In the experimental group, PTH was injected subcutaneously at 20 µg/kg (PTH (1–34)) every other day, and in the control group, PTH was replaced with 1 ml saline. The healing cartilages were assessed at postoperative days 7, 14, 21, and 28. Observation of gross specimens, hematoxylin eosin staining and Safranin O/fast green staining found that every-other-day subcutaneous injection of PTH at 20 µg/kg promoted healing of condylar cartilage and subchondral osteogenesis in the fracture site. Immunohistochemistry and polymerase chain reaction showed that PTH significantly upregulated the chondrogenic genes Sox9 and Col2a1 in the cartilage fracture site within 7–21 postoperative days in the experimental group than those in the control group, while it downregulated the cartilage inflammation gene matrix metalloproteinase-13 and chondrocyte terminal differentiation gene ColX. In summary, exogenous PTH can stimulate the formation of cartilage matrix by triggering Sox9 expression at the early stage of cartilage healing, and it provides a potential therapeutic protocol for high fractures of the mandibular condyle.

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