By Kelsi Matylewicz/Benco Dental Social Media Intern

According to research published in The Journal of the American Dental Association, red hair is caused by variants of the melanocortin-1 receptor (MC1R) gene, which in red-colored hair produces pheomelanin (results in red hair and fair skin). The researchers think that redheads are more sensitive to pain because of this mutation.

What does this mean for dental patients? People with naturally red hair often need larger amounts of anesthesia or local Novocaine than those with blonde or brown hair, whose melanocortin-1 receptor produces melanin.

According to The New York Times,

The MC1R gene belongs to a family of receptors that include pain receptors in the brain, and as a result, a mutation in the gene appears to influence the body’s sensitivity to pain. A 2004 study showed that redheads require, on average, about 20 percent more general anesthesia than people with dark hair or blond coloring. And in 2005, researchers found that redheads are more resistant to the effects of local anesthesia, such as the numbing drugs used by dentists.

Although this mutation can also occur in people with brown hair, it is less common.

The Journal of American Dental Association reported its method:

  • 144 participants* were enrolled(67 natural red-haired and 77 dark-haired)

  • aged 18 to 41 years in a cross-sectional observational study.

* “Participants completed validated survey instruments designed to measure general and dental care–specific anxiety, fear of dental pain and previous dental care avoidance. The authors genotyped participants’ blood samples to detect variants associated with natural red hair color,” according to the JADA report.

The results showed that 86% of the participants had MC1R gene variants (65 of the 67 red-haired participants and 20 of the 77 dark-haired participants). People with the MC1R gene variant had more dental care–related anxiety and fear of dental pain than those without the gene variant. And they were more than twice as likely to avoid dental care.

For more of the story and additional thoughts from Dr. Daniel I. Sessler, an anesthesiologist and chairman of the department of outcomes research at the Cleveland Clinic, read:

Also, check out a dental student’s take on the topic at Mouthing Off, The Blog of the American Student Dental Association.