Hosomichi Jun, Kuma Yo-Ichiro, Oishi Shuji, Nagai Hisashi, Maeda Hideyuki, Usumi-Fujita Risa, Shimizu Yasuhiro, Kaneko Sawa, Shitano Chisa, Suzuki Jun-Ichi, Yoshida Ken-Ichi, Ono Takashi
Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Am J Orthod Dentofacial Orthop. 2017 Feb;151(2):363-371. doi: 10.1016/j.ajodo.2016.02.033.
In this study, we aimed to examine the role of intermittent hypoxia (IH) in dentofacial morphologic changes in growing rats.
Seven-week-old male rats were exposed to IH at 20 cycles per hour (nadir of 4% oxygen to peak of 21% oxygen) for 8 hours per day for 6 weeks. Control rats were exposed to normoxia (N). Maxillofacial growth was compared between the 2 groups by linear measurements on cephalometric radiographs. To examine the dental arch morphology, study models and microcomputed tomography images of the jaws were taken. Additionally, tongue size was measured.
The gonial angle and the ramus of the mandible were smaller in the IH group than in the N group, whereas the body weights were not different between the 2 groups. Morphometric analysis of the dentition showed a significantly wider mandibular dentition and narrower maxillary dentition in the IH than in the N group. The relative width (+4.2 %) and length (tongue apex to vallate papillae, +3.5 %) of the tongue to the mandible were significantly greater in the IH group than in the N group.
IH induced dentofacial morphologic discrepancies in growing rats.
在本研究中，我们旨在探讨间歇性低氧（IH）在生长中大鼠牙颌面形态变化中的作用。
将7周龄雄性大鼠每天暴露于每小时20个循环（氧含量从4%的最低点到21%的峰值）的间歇性低氧环境中，持续8小时，共6周。对照大鼠暴露于常氧环境（N）。通过对头影测量X线片进行线性测量，比较两组的颌面生长情况。为了检查牙弓形态，拍摄了研究模型和颌骨的微型计算机断层扫描图像。此外，还测量了舌头大小。
IH组的下颌角和下颌升支比N组小，而两组的体重没有差异。牙列形态测量分析显示，与N组相比，IH组下颌牙列明显更宽，上颌牙列更窄。IH组舌头相对于下颌骨的相对宽度（+4.2%）和长度（舌尖到轮廓乳头，+3.5%）显著大于N组。
IH导致生长中大鼠出现牙颌面形态差异。
