August 1, 2009
Redheads Have Greater Fear Of Dentists
Studies have suggested that redheads may be more sensitive to pain and may require more anesthetics.
This month's Journal of the American Dental Association published new research findings that the expectation of painful experiences at the hand of a dentist might incite greater trepidation for redheads. They proved to be twice as likely to avoid the dentist as those with dark hair.
"Redheads are sensitive to pain," said co-author Dr. Daniel Sessler, an Outcomes Research Department chair at The Cleveland Clinic, in Cleveland, Ohio.
"They require more generalized anesthesia, localized anesthesia. The conventional doses fail. They have bad experiences at the dentist and because of the bad experiences, they could avoid dental care."
Sessler is an anesthesiologist who began observing redheads' sensitivity to pain after hearing colleagues discussing the subject.
"The persistent rumor in the anesthesia community was that redheads were difficult to anesthetize," said Sessler. "They didn't go under, had a lot of pain, and didn't respond well to anesthesia. Urban legends usually don't start studies, but it was such an intriguing observation."
Two studies came from this observation.
In 2004, research revealed that people with red hair need 20 percent more general anesthesia than blonds and brunettes.
In 2005, a study indicated that redheads also experience increased sensitivity to thermal pain and have a greater resistance to local anesthesia.
Researchers believe it's all about the genes. Variants of the melanocortin-1 receptor gene seem to play a role. This MC1R gene produces melanin, which gives color to skin, hair and eyes.
Blonde, brunette and black-haired people produce melanin, but red-haired people have a certain mutation of this receptor. The mutated receptor produces a different coloring called pheomelanin, which causes freckles, fair skin and ginger hair. These characteristics are found in approximately 5 percent of Caucasians.
Researchers have yet to get a good grasp of the relationship between MC1R and pain sensitivity, but they have found MC1R receptors in the brain and some of them are known to influence pain sensitivity.
Variants of the MC1R gene are not exclusive to red-heads. The dental study involving 144 test subjects found that about 25 percent of the non-redheads also had variants of the MC1R gene. They also experienced a heightened state of anxiety surrounding the dentist and more often avoided the dentist than those without the variant.
There have not been any commercial tests on variations of the MC1R gene.
Once Sessler and his colleagues published the first studies about redheads and pain susceptibility, he received nearly 100 e-mails from redheads around the nation providing anecdotes of awful dentist experiences.
In her 25 years of practicing dentistry, associate professor at the University of Louisville's School of Dentistry Dr. Christine Binkley also noted the phenomenon.
She claims that her redheaded patients appeared to be "anxious and didn't get numb. It's a difficult experience for them," said Binkley, one of the study's authors.
However, it did not seem to affect red-heads across the board.
"I have a [redheaded] hygienist that I have to numb up a lot more than normal," said Dr. Peter Vanstrom, an Atlanta, Georgia, dentist. "She's very sensitive. I have another redheaded patient who is tough as nails, but his father is extremely difficult to numb."
Binkley encourages dentists to "pay more attention, evaluate everyone for dental anxiety, and ask them about previous experiences."
"If you know someone's anxious, do different things," she said. "Make sure they're numb before you start working on them."
Also, if a patient has bad experiences with pain, they should discuss it with their dentists.
The next phase of research is to determine whether people with red hair and those with variants of the MCR1 gene need higher doses of anesthesia for dental procedures.
According to the authors, unpleasant experiences at the dentist could make patients less likely to have regular dental care, which would in turn worsen any problems they may already have.
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