BACKGROUND Deglutitive motion of the tongue may function to maintain tooth position. However, the causation between abnormal patterns of orofacial muscle function and dental malocclusion remains unclear. To clarify the pathogenic mechanism of malocclusion, it is important to determine the relative positional relationship between the tongue tip and incisor edge or the dorsal tongue and palate during deglutition. Here, we assessed the utility of 3-T segmented cine-magnetic resonance (MR) imaging, combined with static MR images for hard tissue visualization, in assessing the relationship between the tongue and the surrounding tissues during deglutitive tongue movement. METHODS Cine-MR images were acquired from three healthy female volunteers during deglutition who had no history of swallowing disorder or other chronic illness, normal alignment and occlusion, and a skeletal class I relationship. Three cine-MR images were taken during deglutition in accordance with an auditory cue for each volunteer. During static imaging, custom-made, contrast-medium-filled clear retainers were positioned in the mouth to allow visualization of the upper and lower incisors and hard palate boundaries. Static images were superimposed onto images of the three stages in deglutitive tongue movement, which were selected from a series of cine-MR images. These superimpositions were assessed five times by tracing cephalometric parameters to examine the reproducibility of the method. RESULTS Traces varied little across repeated measurements, and all subjects had a similar pattern of dorsal tongue movement. Tongue-to-palate contact increased slightly during the first to second stage of swallowing and abruptly increased during the second to third stage, while the tongue tip position remained constant. CONCLUSIONS Segmented cine-MR imaging combined with static MR images is useful for assessing soft tissue motion during deglutition. This method is particularly useful in dentistry to evaluate the relationship between tongue function and maxillofacial morphology in terms of orthodontic treatment and orofacial myofunctional therapy, and for improving tongue movement during speech therapy.

中文翻译：

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动态磁共振成像在评估脱胶舌运动中的新应用。

背景技术舌头的脱胶运动可以起到维持牙齿位置的作用。然而，口腔颌面肌肉功能异常模式与错牙合的原因尚不清楚。为了弄清咬合不正的致病机理，重要的是确定脱除过程中舌尖和门齿边缘或背舌和pa之间的相对位置关系。在这里，我们评估了3-T分段电影磁共振（MR）成像与静态MR图像结合用于硬组织可视化的实用性，以评估在消融性舌头运动期间舌头与周围组织之间的关系。方法Cine-MR图像是从3名健康女性志愿者在妊娠期间获得的，他们没有吞咽障碍或其他慢性疾病的病史，正常的对齐和遮挡，以及骨骼I类关系。根据每个受试者的听觉线索，在脱水过程中拍摄了三张cine-MR图像。在静态成像过程中，将定制的，造影剂填充的透明保持器放置在嘴中，以可视化上下切牙和硬boundaries边界。静态图像叠加在减粘舌运动的三个阶段的图像上，这些图像选自一系列的cine-MR图像。通过跟踪头颅测量参数对这些叠加进行五次评估，以检查该方法的可重复性。结果在重复测量中，痕量变化不大，所有受试者的背侧舌头运动都有相似的模式。在吞咽的第一到第二阶段，舌头与上颚的接触略有增加，而在第二到第三阶段，舌头与舌头的接触突然增加，而舌尖的位置保持恒定。结论分段电影MR成像与静态MR图像结合可用于评估脱粘过程中的软组织运动。该方法在牙科方面特别有用，以评估在正畸治疗和口腔面部肌功能治疗方面舌功能与颌面形态之间的关系，并在语音治疗期间改善舌的运动。