Figure 1. Schematic representation of mouse chromosome 12 and cephalometric landmarks. (a) Mouse chromosome 12. Note that B6.D2.12P does not include the Mit 7 44cM region; however, B6.D2.12M and B6.D2.12C do. (b) Submental-vertex cephalographs of a skull. Zygomatic arch width was measured between points Zb and Zc (horizontal arrow). Snout length was measured between points I and Za (vertical arrow). I indicates the most anterior inter-dental point of the nasal bone. Za indicates the mid-sagittal point intercrossed with the line connecting bilateral anterior points of the zygoma. Zb indicates the deepest lateral surface of the maxilla from the zygomatic arch. Zc is the point on the zygomatic arch lateral to Zb.