The Anatomical Record Celebrates Its Continuing Exploration of the Vertebrate Skull With Our First Two Part Special Issue: Understanding the Zygoma.

Abstract

As those who follow The Anatomical Record know, we are very proud of our Thematic and Special Issues, in recent years covering a range of topics that reflect the finest science from our contributors. One thread of investigation that has a long and robust history of reportage in the Journal is that dealing with the general area of craniofacial biology. This includes aspects of vertebrate development, adaptation, extant variation, pathology, and evolution. Within the last decade alone, The Anatomical Record has published Special Issues focusing on paranasal sinuses and the pneumatization process (Laitman, 2008; Marquez, 2008); aspects of temporal bone biology, hearing, and vestibular systems (Laitman, 2012; Van De Water, 2012); and one of the most comprehensive collections to date on the structure of the nose, ethmoid, turbinates, and nasal bone milieu in vertebrates (Laitman, 2014; Van Valkenburgh et al., 2014). These studies have advanced our collective understanding of craniofacial and head and neck biology in many areas. This current Special Issue, “Understanding the Zygoma: A Key Morphofunctional Partition in the Craniofacial Skeleton,” Guest Edited by Paul Dechow and Qian Wang (Dechow and Wang, 2016, this issue) of Texas A&M University College of Dentistry, approaches a bone and its contiguous structures that have been under-investigated compared to many other areas of the mammalian skull. The zygoma, often called the zygomatic bone or malar bone in mammals, has evolved from the jugal bone found in most reptiles, amphibians, and birds. The zygoma is quite important in many dinosaurs because it forms part of the orbital series, and has often received a great deal of attention in reconstructions of partial remains. In mammals, the zygoma has received attention, of course, but much less so than other bones of the face, such as the teeth-inhabiting maxilla or the mandible. Given the zygoma's pivotal location at the interface of so many developmental and biomechanical forces, it is surprising that more studies have not focused upon the bone. Although the zygoma has not received as much attention historically as some other aspects of the skull, some prominent anatomists have published their findings on it in The Anatomical Record. Of particular note is the 1919 paper by noted craniologist Bruno Oetteking comparing the angulations of the frontosphenoidalis portions of the zygoma in an attempt to determine how the bony orbits compare among humans, great and lesser apes, and through that gain insights into evolutionary ties (Oetteking, 1919). While not focusing solely on the zygoma, the experimental studies on dogs by Canadians Giblin and Alley in the early 1940s explored in detail the global effects premature suture closure in part of the cranial vault can have in other areas, such as the zygomatic arch and bone (Giblin and Alley, 1942, 1944). Jumping considerably ahead in time and sophistication, studies by anatomist Susan Herring (Herring et al, 1996; Teng et al., 1997) in her laboratory at the University of Washington are indicative of the type of insightful work that was being done experimentally in the 1980s and 1990s on cranial bones. In these particular studies, Herring et al. focused specifically on the zygomatic arch in experimental pigs, testing strain and resultant bone architectural patterning, and assessing various regions and components of the zygomatic complex. Their work has been most important to understanding the relationship of strain to underlying architecture. Herring's work is represented again in the current Special Issue. The Guest Editors have put an enormous amount of effort in bringing together research on the zygoma from many different approaches and perspectives, so much so that for the first time The Anatomical Record will present a Special Issue in two parts: The first part, focusing on “Development, Adaptation, Structure and Function of the Zygoma” is appearing in this December, 2016, Issue. The second half will focus on the “Evolution of the Zygoma” and appear in January of 2017. We are very proud that The Anatomical Record will continue to present the finest studies exploring advances in craniofacial biology and shine a light on the multi-dimensional importance of the zygoma and its connections. Jeffrey T. Laitman Senior Associate Editor The Anatomical Record Kurt H. Albertine Editor-in-Chief The Anatomical Record