“While the rest of the species is descended from apes, redheads are descended from cats.” ― Mark Twain
It’s a well known fact in the dental world that individuals with red hair tend to have a difficult time at the dentist. Our resident redhead, Kris, can confirm that this is not an urban legend. When in the rare instance that she needs lidocaine (local anesthesia), she is sure to tell us that she needs ‘A LOT’.
Research has shown that people with red hair tend to be particularly nervous about dental procedures, and as a result are twice as likely to avoid going to the dentist as blondes, brunettes and black haired individuals. Part of this nervousness arises around the challenges of getting numb, which often leads to the need for multiple shots of lidocaine. An unpleasant proposition for anyone.
Red hair is caused by a mutation on chromosome 16 that affects the melanocortin-1 receptor (MC1R) protein, leading to redhead’s characteristic pale skin, light eyes and the need for slathering on the sunblock.
The MC1R gene also belongs to a family of receptors that include pain receptors in the brain, and as a result, a change in this gene changes the body’s sensitivity to pain. Hence, redheads need about 20% more general anesthesia than people with dark or blond coloring, and have heightened resistance to local anesthesia (lidocaine). This leads to the unpleasant situation of requiring multiple shots to get comfortably numb.
Now, those of us with brown or black hair, are not necessarily spared the wrath of this mutation. About 25% of those with darker hair have a variant of the MC1R gene, and like their redhead brethren similarly share their anxiety of the dentist. Furthermore, while the gene for red hair is recessive (ie. both parents must carry it in order for there to be a chance of having a red-haired child), 80% of the global population carries the redheaded gene albeit invisibly.
At the genetic level at least, we’re almost all red heads!