Collaborative research: A histological and CT study of midfacial growth trajectories in subadult primates

灵长类动物与大多数其他哺乳动物的区别在于面部中部的缩小趋势，最明显的是猴子、猿和人类的“鼻子”缩小。本研究采用一种新颖的发育方法来测试灵长类动物颅骨的面中缩小是否是邻近结构（如眼睛和牙齿）生长的副产品。例如，选择一个早熟的视觉神经系统是否会从根本上影响面部中部的生长模式？比例较大的乳牙及其后继牙对上颌骨鼻旁间隙的发育有短暂或持久的影响吗？为了回答这些问题，将研究来自70多个标本（包括20种灵长类动物）的尸体样本。不同出生年龄的标本将使用高分辨率计算机断层扫描（CT）和脱钙样品显微研究的创新组合进行研究。结果是一个新的方法来绘制区域骨沉积和吸收在三维。该项目将创建独特的灵长类头骨三维“生长图”，与头部的功能单位（眼睛，鼻道，牙齿）有关。三维颅骨形状和生长图将在不同程度的灵长类动物之间进行比较，这些灵长类动物的眼睛是会聚的（朝向前方）。对神经和牙齿发育的间接影响，如妊娠期长短和饮食，也将作为变量使用。该研究的更广泛的意义包括基于网络的地图集和标本的组织学和CT图像的数字档案。交互式在线地图集将作为解剖学家和灵长类动物学家的资源开发，解剖学家将受益于研究人类发展方面的动物模型，而灵长类动物学家将受益于研究灵长类动物发展的资源。此外，还将制作动画，突出进化适应的生长机制的重要性，并将其作为在线教育工具提供给高级K-12学生和他们的老师。

Primates are distinguished from most other mammals by a trend toward midfacial reduction, most notably seen in the reduced 'snout' of monkeys, apes, and humans. This study uses a novel developmental approach to test whether midfacial reduction of the skull in primates is a byproduct of growth of neighboring structures (e.g., eyes and teeth). For example, does selection for a precocious visual nervous system fundamentally affect midfacial patterns of growth? Do proportionately large deciduous maxillary teeth and their successors have transient or lasting effects on development of paranasal spaces of the maxilla? To answer these questions, cadaveric samples from over seventy specimens (including 20 species of primates) will be studied. Specimens of different postnatal ages will be studied using an innovative combination of high-resolution computed tomography (CT) and microscopic study of decalcified samples. The result is a novel approach for mapping regions of bone deposition and resorption in three dimensions. The project will create unique three-dimensional 'growth maps' of primate skulls in relation to functional units of the head (eyes, nasal airways, teeth). Three-dimensional skull form and growth maps will then be compared among primates that differ in the extent to which the eyes are convergent (forward-facing). Indirect influences on neural and dental development, such as gestation length and diet, will also be used as variables.The broader implications of the study include a web-based atlas and digital archive of histological and CT images from the specimens. The interactive online atlas will be developed as a resource for anatomists, who will benefit from animal models for aspects of human development, and primatologists, who will benefit from the resource on development of primates. In addition, animations which highlight the importance of growth mechanisms for evolutionary adaptation will be created and made available to advanced K-12 students and their teachers as online educational tools.