Collaborative Research: Developmental links between teeth and faces

脸从出生到成年都在变化。生长和萌出的牙齿是面部外观变化的最具变革性的驱动因素之一，促进骨骼形成并影响整体颌骨生长。以前的研究集中在“乳牙”或乳牙的萌出，以及随后的恒牙。然而，在接近出生或出生时，许多牙齿尚未完全发育，很少被研究。这项研究调查了牙齿在早期关键时期面部发育中的作用，结果有助于更好地了解解剖学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学生生成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矩阵理论的基础，该理论认为，软组织结构和其他器官（如牙齿）的边界骨骼直接导致骨骼形态的转变。主要研究人员使用下颌的两侧来研究牙齿和下颌形成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。三维重建是使用微型计算机断层扫描（µCT）扫描来检测骨骼，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胚。Amira软件用于生成表示关键细胞和组织水平机制的三维视图（即，用于骨沉积和再吸收以及骨细胞成熟的细胞信号）。µCT还将用于形态测定分析。最终，通过调查发育中的牙齿如何在不断生长的面部中争夺空间，结果与解释现代和过去解剖学的变化有关。该奖项反映了NSF的法定使命，并通过使用基金会的智力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.