Among the first to see numerous problems among dial painters were dentists. Dental pain, loose teeth, lesions and ulcers, and the failure of tooth extractions to heal were some of these conditions. Many of the women later began to suffer from anaemia, bone fractures, and necrosis of the jaw, a condition now known as radium jaw. The women also suffered from suppression of menstruation, and sterility. It is thought that the X-ray machines used by the medical investigators may have contributed to some of the sickened workers' ill-health by subjecting them to additional radiation. It turned out at least one of the examinations was a ruse, part of a campaign of disinformation started by the defence contractor. U.S. Radium and other watch-dial companies rejected claims that the afflicted workers were suffering from exposure to radium. For some time, doctors, dentists, and researchers complied with requests from the companies not to release their data.