Jose Armos, 28, a paramedic who lives in Miami, looked so young that, when responding to 911 calls, he seemed to add to some patients’ distress.

“They would look at me and be like, ‘O.K., is this 16-year-old really going to take care of me?’ ” said Mr. Armos, who had the sparsest of beards. “It was hard for people to trust me because I had that baby face.”

Earlier this year, Mr. Armos visited the Miami office of Dr. Jeffrey S. Epstein, a hair restoration surgeon. “I wanted that stronger, manlier look,” Mr. Armos said.

He had a full beard transplant, from sideburns to chin, at a cost of about $7,000. More than a thousand individual hair follicles were harvested from the back of his head, where hair grows thickest, and transplanted to his face.