Doctoral Dissertation Research: Assessing the chewing function of the hyoid bone and the suprahyoid muscles in primates

舌骨是一块小的u形骨，位于舌头的底部和喉头（音盒）的顶部。这块骨头的形状和肌肉对舌头的运动、咀嚼、吞咽和发声都很重要。本博士论文研究了舌骨的形状、位置和肌肉附着之间的关系，以确定该骨在灵长类动物摄食中的作用。这项工作使研究人员了解舌骨的功能，这可能导致形成新的治疗人类语言和吞咽障碍的方法。这项工作还通过支持本科生和研究生的培训，以及创建一个公开可用的微ct扫描数据集来培养STEM人才，该数据集可用于针对K-12学生和公众的科学推广项目。总的来说，这项工作旨在教育公众科学和进化概念，培养和鼓励未来的研究人员，并增加对头颈部解剖和功能的当前理解，这具有重要的生物医学意义。舌骨和连接它与头骨的肌肉（即舌骨上肌）是咀嚼、吞咽、舌头操纵和发声的核心。这些行为，特别是那些与进食有关的行为，如何影响舌骨解剖尚不清楚，因为以前的工作主要集中在发声作为舌骨形状的驱动因素上。舌骨在进食时几乎不间断地运动，在吞咽时被舌骨上肌拉向口腔。本研究的目的是通过评估舌骨形状和位置的变化及其与灵长类动物舌骨上肌和颅骨的关系来量化吞咽的影响。该项目利用微ct扫描和碘染色方法可视化舌骨器官以及3D形状分析来研究舌骨、颅骨和肌肉组织之间的关系。此外，本研究还分析了在饮食差异显著的两种近亲灵长类动物的生长发育过程中，这些关系是如何变化的。这样，这项工作可以为人类舌骨形状和功能的进化提供有价值的见解，并将人类舌骨解剖学置于灵长类舌骨变异的更广泛背景下。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The hyoid is a small u-shaped bone that sits at the base of the tongue and the top of the larynx (voice box). The shape and muscular attachments to this bone are important for tongue movements, chewing, swallowing, and vocalization. This doctoral dissertation research investigates the relationship between shape, position, and muscular attachment of the hyoid to determine the role of this bone in feeding across primates. This work informs researchers about the function of the hyoid, which may result in the formation of novel treatments for speech and swallowing disorders in humans. This work also builds STEM talent by supporting undergraduate and graduate training and creating an openly available dataset of microCT scans that can be used in scientific outreach projects aimed at K-12 students and the public. Overall, this work is poised to educate the public on scientific and evolutionary concepts, build and encourage future researchers, and add to the current understanding of head and neck anatomy and function, which has important biomedical implications. The hyoid and the muscles that connect it to the skull (i.e., the suprahyoid muscles), are central to chewing, swallowing, tongue manipulation, and vocalization. How these behaviors, specifically those involved in feeding, affect hyoid anatomy is not well known as previous work has focused on vocalization as a driving factor for hyoid shape. The hyoid is in near-constant motion during feeding and is pulled toward the oral cavity during swallowing by the suprahyoid muscles. The goal of this research is to quantify the impact of swallowing by evaluating variation in hyoid shape and position and their relationship to the suprahyoid muscles and skull in primates. This project utilizes microCT scans and iodine staining methods to visualize the hyoid apparatus along with 3D shape analyses to investigate the relationships between the hyoid, skull, and musculature. Additionally, this work analyzes how these relationships change throughout growth and development in two closely related species of primates with notable differences in diet. In doing so, this work can provide valuable insights into the evolution of human hyoid shape and function and put human hyoid anatomy into the broader context of primate hyoid variation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.