%0 Journal Article
%T Effects of unilateral nasal obstruction on the characteristics of jaw-closing muscles in growing rats
%A Huan Tang
%A Ikuo Yonemitsu
%A Jun Hosomichi
%A Kenzo Watakabe
%A Shunichi Shibata
%A Takashi Ono
%A Yuhei Ikeda
%J -
%@ 1945-7103
%D 2019
%R https://doi.org/10.2319/021918-132.1
%X ABSTRACT Objectives: Mouth breathing caused by nasal obstruction (owing to abnormal pressure of masticatory muscles) affects craniofacial growth and development. The influence of unilateral nasal obstruction on jaw-closing muscles was investigated in rats to reveal one of the etiologic mechanisms. Materials and Methods: Forty 8-day-old male Wistar rats were used in this study. Experimental rats were subjected to left-sided nasal obstruction by burning the external nostril tissue at the age of 8 days. Pulse oxygen saturation was recorded each week. Morphologic changes were evaluated by staining with hematoxylin and eosin (to assess the cross-sectional area) and by adenosine triphosphatase activity staining (to assess the myosin heavy chain isoform composition). Immunohistochemical and reverse transcription quantitative real-time polymerase chain reaction analyses of tumor necrosis factor-¦Á and glucose transporter 4 were carried out at 5 and 9 weeks of age. Results: The cross-sectional area of the jaw-closing muscles was lower in the experimental group at 9 weeks of age. The percentage of myosin heavy chain-2a in masseter muscles was increased in the experimental group compared with the control group. An increase in the tumor necrosis factor-¦Á messenger RNA and protein levels and a decrease in the glucose transporter 4 messenger RNA and protein levels at 5 and 9 weeks of age in the jaw-closing muscles in the experimental group were noted. Conclusions: Unilateral nasal obstruction could affect the morphology and contractile characteristics of jaw-closing muscles during growth in rats.
%K Unilateral nasal obstruction Jaw-closing muscle Tumor necrosis factor-¦Á (TNF-¦Á) Glucose transporter 4 (GLUT4) Myosin heavy chain (MHC)
%U http://www.angle.org/doi/abs/10.2319/021918-132.1