Collaborative Research: Developmental links between teeth and faces

面孔从出生到成年都会发生变化。生长和出牙是面部外观变化最具变革性的驱动因素之一，促进骨形成并影响整体颌骨生长。先前的研究集中在“乳牙”或乳牙的长出，以及随后的恒牙。然而，在临近或出生时，许多牙齿尚未发育完全的时期，很少被研究过。本研究调查了牙齿在早期关键时期面部发育中的作用，其结果有助于更好地理解解剖结构的不同部分如何影响他人以及整个生物体的外观。该项目为K-12学生提供3D模型、网站和其他资源，并为一名博士后学者和多名研究生和本科生提供培训和专业发展。这项研究调查了功能基质理论的基础，该理论认为，与软组织结构和其他器官（如牙齿）接壤的骨骼直接导致骨形态的转变。主要研究人员使用下颌两侧来研究牙齿和下颌形成过程中的细胞和组织水平事件，然后将其反映在下颌另一侧的三维重建上。三维重建是使用微计算机断层扫描（µCT）来检测骨骼，然后在将一半颌骨浸泡在碘中后进行第二次扫描，之后使用µCT很容易检测到未矿化的牙齿细菌。Amira软件用于生成三维视图，表示关键的细胞和组织水平机制（即骨沉积和吸收的细胞信号，以及骨细胞成熟）。微CT也将用于形态计量学分析。最终，通过研究发育中的牙齿如何在生长的面部竞争空间，结果与解释现代和过去解剖学的变化有关。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。

Faces transform from birth to adulthood. Growing and erupting teeth are among the most transformative drivers of changes in facial appearance, promoting bone formation and influencing overall jaw growth. Prior research has focused on the eruption of ‘baby teeth’, or deciduous teeth, and subsequent permanent teeth. However, the period near or at birth, when many teeth are not yet fully developed, has rarely been studied. This study investigates the role(s) of teeth in facial development during early critical periods, and results inform a better understanding regarding how different parts of anatomy can influence the appearance of others, as well as the whole organism. The project generates 3D models, a website and other resources for K-12 students and provides training and professional development to one postdoctoral scholar and multiple graduate and undergraduate students. This study investigates the underpinnings of functional matrix theory, which posits that bones that border soft tissue structures and other organs such as teeth, directly cause transformations of bone morphology. The principal investigators use the two sides of lower jaw to study cellular and tissue-level event in tooth and jaw formation, which are then mirrored on three-dimensional reconstructions of the opposite side of the jaw. The three-dimensional reconstructions are accomplished using micro computed tomographic (µCT) scanning to detect bone, following by a second scan after soaking half of the jaw in iodine, after which unmineralized tooth germs are easily detectable using µCT. Amira software are used to generate three-dimensional views that denote critical cellular and tissue-level mechanisms (i.e., cell signals for bone deposition and resorption, and bone cell maturation). µCT will also be used for morphometric analyses. Ultimately, by investigating how developing teeth compete for space within a growing face, results are relevant for interpreting variation in modern and past anatomy.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.