U.S. Air Force Lt. Col. Marshall Humes, 633rd Dental Squadron maxillofacial surgery element chief, teaches 633rd DS dental residents suturing lessons in the USAF Hospital Langley dental clinic at Langley Air Force Base, Va., Sep. 25, 2014. The dental residents practiced Humes’ techniques on pig jaws and cow tongues for additional on-the-job training. Every year, there are six new dental residents operating in the course. (U.S. Air Force photo by Airman 1st Class Devin Scott Michaels)