Faculty Bibliography

The morphology and positional behavior of the last common ancestor of humans and chimpanzees are critical for understanding the evolution of bipedalism. Early 20th century anatomical research supported the view that humans evolved from a suspensory ancestor bearing some resemblance to apes. However, the hand of the 4.4-million-year-old hominin Ardipithecus ramidus purportedly provides evidence that the hominin hand was derived from a more generalized form. Here, we use morphometric and phylogenetic comparative methods to show that Ardipithecus retains suspensory adapted hand morphologies shared with chimpanzees and bonobos. We identify an evolutionary shift in hand morphology between Ardipithecus and Australopithecus that renews questions about the coevolution of hominin manipulative capabilities and obligate bipedalism initially proposed by Darwin. Overall, our results suggest that early hominins evolved from an ancestor with a varied positional repertoire including suspension and vertical climbing, directly affecting the viable range of hypotheses for the origin of our lineage.

NYU School of Medicine recently embarked on a re-design of its anatomy curriculum that decreased the use of cadavers with plastinated specimens. Plastinated models provide an authentic learning experience of the human body, but lack necessary labels outlining important structures. Due to the fragile nature of the specimens, we endeavored to solve the challenge of labeling by developing a digitized supplement and archive of plastinated and pathology specimens. An interdisciplinary team of faculty and multimedia designers at NYU School of Medicine designed and developed electronic resources related to the artistic models and plastinated specimens. Over the course of three months, 60 artistic and plastinated models of different sizes were captured from dozens of angles using a digital camera or an Artec Leo Scanner. The numerous image captures of the plastinated specimens were processed in Agisoft Metashape, a stand-alone software product, that performs photogrammetric processing of digital images and generates 3D spatial data. After Agisoft Metashape exported a complex 3D mesh with a high-resolution texture, anatomy faculty added labels to the digitized 3D anatomy specimens using the Sketchfab web platform. The labeled 3D anatomy models were then uploaded into the Living Anatomy site on NYU School of Medicine's learning management system for students to explore before, during, and after their anatomy lab sessions. Quizzes using these models also were created to help students identify the structures and link them to physiology and clinical scenarios. The digitized 3D models allow students to zoom in, rotate and explore the specimens in a more interactive way, thereby enhancing the process of just observing fragile plastination models. When asked, 84% of students reported that the 3D models of plastinated specimens contributed "very much so" to their learning of anatomical relationships. We will continue to find opportunities for the meaningful integration of these 3D models within the anatomy curriculum as well as into other pre-clerkship and clerkship modules. We will also assess the educational outcomes of the 3D models and, by doing so, will incorporate instructional design into the process.

Background: The occurrence of bifid mandibular canals is unusual but not rare. Previous reviews and case studies have described numerous types of bifid canals based on location, anatomy, and contents. Developmentally, ossification of the mandible begins at the region of the mental foramen and continues posteriorly, forming the mandibular canal around the neurovascular bundle within. This process explains the creation of multiple mandibular canals and the diversity of canal types previously recorded in the literature. However, the presence of two distinct mandibular canals, each originating from its own mandibular foramen, is even more unusual. Material(s) and Method(s): This case report describes a unilateral variant discovered during the dissection of a 92-year-old African American female. Result(s): On the left side, the cadaver presents two distinct mandibular canals, each containing a branch of the inferior alveolar artery and mandibular nerve, the third division of the trigeminal. The nerves within the two canals were distinct from each other at the level of the posterior division of the mandibular nerve, within 1 cm of foramen ovale. Conclusion(s): This is the first description of such an occurrence and emphasizes the need for identification of the contents of a bifid or accessory mandibular canal prior to invasive procedures.