By the 1950s, men had been seeking — and failing to find — a remedy for hair loss since at least 1550 B.C., when doctors in ancient Egypt recommended anointing bald scalps with the fat of a Nubian ibex or a crushed black lizard boiled in oil.

Then along came a young dermatologist named Norman Orentreich, who tried an experiment: transplanting hair from the back of the head to the scalp. And lo, the transplanted hair grew.

Thanks in part to his discovery, a multibillion-dollar global hair transplant industry now exists to provide long-term relief for receding hairlines. His breakthrough also established him as a maverick in cosmetic medicine and a magnet for media coverage, and it ultimately embedded hair plugs in American culture as a totem of male midlife crises — as well as the butt of late-night television jokes.

Dr. Orentreich (pronounced OR-en-trike), who died on Jan. 23 at 96, went on to develop other cosmetic countermeasures for aging, but not without controversy. One of his novel treatments — injecting tiny droplets of liquid silicone in the skin to smooth facial wrinkles — raised concerns among some of his peers and drew regulatory scrutiny.