How Intermittent Hypoxia Impacts Jaw Cartilage Growth adminJuly 28, 2023 Histological changes in mandibular condylar cartilage of IH rats. (a) Representative images of toluidine blue-stained sagittal sections of mandibular condyle from the N and IH groups. Thickness of each cartilage layer of anterior (b), middle (c), and posterior (d) parts in mandibular condyle. Ratios of each cartilage layer to total cartilage thickness shown in panels (e–g). F fibrous layer, P proliferating layer, M maturative layer, H hypertrophic layer. Scale bar = 100 μm. Data are mean ± SEM for each group. *P < 0.05. CREDIT: DEPARTMENT OF ORTHODONTIC SCIENCE, TMDU “We observed inhibited growth of the cartilage in the rat jaws,” says Takashi Ono, senior author and a professor, in a release. “Interestingly, the tibial cartilage was not affected by the hypoxic air exposure.” The authors also saw decreased expression levels of two genes called TGF-β and SOX9 in the jaw cartilage of the rats exposed to intermittent hypoxia, while another gene named collagen X displayed increased expression. “The gene expression patterns we observed in the jaw cartilage of the rats exposed to hypoxia were consistent with hypertrophy,” says Lekvijittada. “This indicates that the jaw cartilage had restricted growth. We did not see these patterns in the tibial cartilage.” The findings of this study deliver novel insight into how being exposed to periods of low oxygen levels can affect jaw cartilage growth and development with potential applications in orthopedic medicine and diagnosis of temporomandibular disorders. This work also provides further understanding of how cartilage throughout the body differs depending on its location. Photo 206979091 © Nupino – Dreamstime.com
