Ehlers Danlos Syndrome is a group of similar inherited disorders that adversely affect the connective tissue. Patients with this disease experience problems in the skin, joints, blood vessels, and other areas. In addition, some disorders within the syndrome also make the individual resistant to local anesthesia.
Unfortunately very few dentists are aware of this phenomenon. And in addition, there are patients out there with undiagnosed Ehlers Danlos, as well as patients with EDS who are not aware of the issues with local anesthesia. What happens? The patient ends up having a very unpleasant time at the dentist with both the dentist and patient trying to figure out what is going on!
About Ehlers Danlos Syndrome
It is not the point of this blog post to talk about the Syndrome in great detail. There are plenty of other sites out there that accomplish this. However, to understand how this affects dentistry and the dreaded “novocaine shot,” you need to know a bit about the disease.
Ehlers Danlos affects connective tissue. Connective tissue is basically the “glue” that holds other tissue and organs together. Specifially, there are defects with the production of collagen, which is the major protein in connective tissue. While there are six major types of EDS, they are all generally characterized by hypermobile joints (joints that can move way beyond what would be considered normal), joint pain, fragile and easily bruised skin, and other findings.
Not all of the genes responsible for Ehlers Danlos are known and there is active research into all parts of this syndrome.
Why Does Local Anesthesia Not Always Work?
First, it needs to be mentioned that not all of the six types of EDS make the patient resistant to dental local anesthetic. Based on research (here and here), it appears that Type III – Hypermobility is the one in which this phenomenon is seen.
Unfortunately, the mechanism behind why the local anesthesia is less effective is not well understood. The current theory focuses on the “looseness” of the connective tissue. Since the connective tissue is defective, it is very easy for the local anesthetic to quickly move away from the site that is being anesthetized. Stated another way, the connective tissue barriers that hold the local anesthesia in place for the duration of the dental procedure are weak and easily broken.
The end result is that the patient is not sufficiently numb for the dental procedure, leading to pain. Patients get confused, discouraged, angry, and ultimately avoid the dentist, which then makes things even worse down the road.
What Should Dental Patients Do?
As a dentist who treats patients in private practice, I am disappointed that this issue is not well known in the dental community. Ask most dentists and unfortunately, most will not be aware of this. In fact, in what is considered the bible of dental local anesthesia (A Handbook of Local Anesthesia by Stanley Malamed), there is no mention of phenomenon (I searched the 6th edition).
Here are some tips:
- Find a dentist who has experience with Ehlers Danlos. There is nothing wrong with calling an office and asking if the dentist is familiar with EDS and this local anesthetic phenomenon.
- Identify yourself early on as having Ehlers Danlos to the hygienist and dentist.
- Find an opportunity to meet with the dentist in advance of any procedure requiring local anesthetic to review the plan (remember that the office may have to order a special type of local anesthetic).
- Consider taking a medication beforehand to relax you.
- Be ready for a longer than normal appointment.
- At the completion of the appointment, especially if it was successful, ask the dentist for detailed records on the local anesthesia (what local anesthetic, how much administered, where administered, etc.)
In some cases, nitrous oxide and/or IV sedation may be necessary to complement the local anesthesia.
My own experience treating patients with Ehlers Danlos has shown that most of the time, we can achieve local anesthesia. I attribute my success to knowing the pharmacology of local anesthetics as well as other injection techniques. To use a pun based on EDS, with a little “flexibility” in selecting local anesthetics and injection sites, we can nearly always succeed!