Science + Tech

Why redheads need more local anesthesia

This post originally appeared on July 3, 2015

redheadDental students have done it hundreds of times already: local anesthesia. It may be the only procedure we have 100% confidence in completing. It’s like July 4th fireworks going off in dental brains because the patient’s “lip feels huge” and it is time to start the procedure. Yet, on a rare occasion, when we go through the normal routine with the appropriate dosage of anesthesia, they still have sensation. What gives?

Some patients have a rare variant of the “MC1R” gene that be directly correlated with being more sensitive to pain, therefore being more difficult to anesthetize. While there is no gene mapping option to find this variation and predict this abnormal tolerance, this gene produces melanin responsible for hair color and skin tone. So, these tolerant patients may be more easily identified by observing the color of their hair.

Two studies were conducted and the results were that, when compared to blondes and brunettes, redheads were more resistant to the effects of local anesthesia. They need on average 20% more general anesthesia!

In addition to being weary of delivering enough local, dentists need to be cautious of the fact that past experiences of failed local anesthesia causes extreme dental anxiety in patients. Because of this, redheads are twice as likely to avoid dental care than individuals who have darker hair colors.

What can we do to make sure that we are making red heads are comfortable and will return for routine dental care? Red, White and Blue. Redirect dental anxiety, ask white coat history of pain tolerance, and check for cancer out of the blue.

Redirect dental anxiety: Be sensitive and tolerant to those with dental anxiety. If someone has a bad experience they may never want to return to a dentist. A lot of dental anxiety is associated with expectations of pain or a bad experience. Go above and beyond to make sure the patient is comfortable and assure them that you will take care of them. And always make sure you have achieved analgesia before starting a procedure.

Ask white coat history: In initial assessments in practice or clinic, if you notice your patient has red hair, ask if he or she has experienced a heightened tolerance of pain before. Or if anyone (like a doctor, hence the “white coat”) has ever previously told them that they have been difficult to numb. Then you can expect you might need to deliver more local anesthesia and avoid getting flustered while keeping the patient as comfortable as possible. Perhaps even give a larger dose of topical before you inject.

Check for cancer out of the blue: Patients with red hair often have fair skin with the melanin gene. Make sure you are giving all patients the standard of care and watching out for their overall well being. Examine the skin on their face and arms for skin cancer and sun spots, especially this time of the year, when they are hanging out in the summer sun for extended hours.

Next time you have a redhead in your chair, they may need to experience a little extra white blanching of local to avoid feeling blue!

~Dr. Megan Borak, West Virginia ’16

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2 Comments

  1. It was interesting to read about anesthesia. Thanks for sharing.

  2. Great piece of information. Thank you for sharing.

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