Surgeons who manage this condition are either reconstructive urologic surgeons or plastic surgeons. Surgeons were assisted by surgeon's mates, who after 1805 were called "assistant surgeons". These physicians are called vascular surgeons or phlebologists. The hand surgery field is also practiced by orthopedic surgeons and general surgeons. Cranioplasty for craniosynostosis is performed by pediatric neurosurgeons with or without plastic surgeons. Pilot-physicians are eligible for advanced ratings as both flight surgeons and pilots. This led to the distinction between physicians and surgeons. Many skull surgeries performed by Inca surgeons were successful. There were no strict government regulations in place for physicians, surgeons, and apothecaries. Nitrous oxide is a significant occupational hazard for surgeons, dentists and nurses. There are approximately 20,400 actively practicing orthopedic surgeons and residents in the United States. Procedures by unlicensed surgeons can lead to serious complications. Dr. Mehmet Oz is regarded as one of the most accomplished cardiothoracic surgeons. Salaries for trauma surgeons are comparable to that of general surgeons. These headsets are used by educators, scientists, engineers, military personnel, surgeons, and many more.