A 26-year-old man swallowed his orthodontic retainer, and his stomach pain soon got better. The retainer, however, was not gone. After piercing the wall of his small bowel, it eluded an initial operation, worked its way into a deep muscle near his spine, and left his right leg tingling and aching in a way that looked like a pinched nerve.
Surgeons at Kyung Hee University Hospital at Gangdong in Seoul, South Korea, described the case in the Sept. 25, 2026, issue of the journal Medicine. The authors, Hyun Gu Lee, Hayoung Lee, and Youn Young Park of the hospital's Department of Surgery, wrote that migration of a swallowed sharp object into the psoas muscle is exceedingly rare and "can occur silently without peritonitis," which abdominal emergency doctors usually watch for.
