I Passed Out at the Dentist. Why?

As a full time general dentist in private practice, I’ve seen patients faint more than once. And as a dental blogger, I’ve seen all types of comments and questions on this site about patients passing out. In fact, most people mistakenly assume that when something like this happens, it is because they are allergic to something the dentist used. In nearly all cases, that is an incorrect conclusion.

So, why is it that some people faint and/or pass out at the dentist? And what causes it?

Common Medical Emergencies in Dental Offices

In a widely cited survey, the number one emergency seen in a dental office is fainting – or more appropriately called syncope (sources: here and here). In fact, in one study, syncope accounted for 53% of all emergencies in a dental office (source: here). The second most common emergency is hyperventilation.

fainting at the dentist is not treated as an allergic reaction

Many mistakenly assume that fainting at the dentist is due to an allergic reaction.

To many individuals who’ve had adverse reactions at the dentist, this fact can come as quite a surprise. The scenarios that most patients believe are occurring – usually acute allergic reactions as well as cardiac events – very rarely occur.

Fainting vs. Passing Out vs. Vasovagal Syncope

Generally speaking, the above three terms are all roughly the same, with the term vasovagal syncope being the medically appropriate one. It can be defined as a temporary loss of consciousness due to a decrease in blood flow to the brain.

dental needle fear can cause fainting or passing out.

This is the most common trigger for an episode in a dental office.

Your brain is in constant need of oxygen. If blood flow to the brain is temporarily diminished, you are no longer able to function, and you lose consciousness. If this happens, it most often results in you falling to the floor, which then puts your head at the same level as your heart. This change in position, along with the removal of the stimulus which caused the episode (more on this later), then allows for adequate blood to flow to your brain, and you very quickly regain consciousness.

In vasovagal syncope, a trigger (such as the sight of a needle) will cause a susceptible individual’s nervous system to over-react and cause certain physiologic changes which can lead to the decrease in blood flow to the brain.

Common Triggers of Vasovagal Syncope in a Dental Office

dental drill can cause you to pass out or faint

The dental handpiece or “drill” can cause some to pass out.

A dental office is a unique setting in that the patients walking through the door typically don’t want to be in the office, but they know they have to. This is why passing out episodes occur quite frequently. The most common triggers seen in a dental office include:

  • The sight of the needle (this is the number 1 trigger).
  • The slight sting of the dental injection.
  • The sight of blood.
  • The smell of an office.
  • The high pitched squeal of the dental handpiece.
  • And others.

So, if a trigger is experienced by a susceptible individual, the syncope episode can commence.

A Typical Fainting Episode at the Dentist

Each and every episode of passing out is unique, as is every patient. The following is a classic example of what someone might experience in a vasovagal syncopal episode at the dentist.

  • You don’t like coming to the dentist but you know you have to get a filling. You have been dreading it for over a week.
  • You are called in from the reception area. While walking in, you see a needle that looks large and intimidating.
  • The dentist comes in and says hello. At this point, you’re still thinking about the needle, and you begin to feel somewhat lightheaded.
  • You hear the dentist talking to the assistant but their voices seem muffled. You notice that you are breaking out into a sweat, even though the temperature was perfect just a couple of minutes earlier.
  • You begin to have a feeling of nausea and your thoughts appear fuzzy. Your muscles suddenly feel incredibly weak and you don’t even think you could lift your hand. You attempt to say something but you can’t muster the strength or thoughts to put words together.
  • Your vision appears compromised, first by seeing bright lights, and then with black or cloudy vision. You are sitting upright but all you want to do is lie down…

Next thing you know, the chair is completely reclined and you are lying horizontally in it. The dentist and the assistant are sitting next to you. The dentist is looking at you intently and is feeling your pulse on your wrist. He/she notices you waking up and says:

“Well, it looks like you fainted for a bit. Don’t worry. It happens more often than you think. We’ll keep you reclined for a couple of more minutes and then we’ll slowly bring the chair up.”

Final Thoughts

If this is anything like similar posts, this will generate a lot of traffic and comments. Please consider reading other posts I have on similar topics. If you think you’re allergic to novocaine, you should read this three part series (one, two, and three). If you think you’re allergic to epinephrine, you need to read this and this. If you’ve had difficulty getting numb, check out this post and this post. Enjoy!

 

Root Canals Get No Lovin’

Root Canal awareness week banner

Root Canal Awareness Week 2014. Logo courtesy AAE.

As we get ready to kick off the 8th annual Root Canal Awareness Week on Sunday March 30, it is remarkable to see that root canals are still perceived to be horribly painful and worse than torture. I outlined this myth in one of my Dental MythBuster posts called Dental MythBuster #3 – Root Canals Hurt!

Needless to say, despite that post getting over 12,000 views, the myth lives on in the popular media. Let’s see where:

  • The New York Times, February 7, 2014. “…taxes you pay on your investments has as much appeal as a root canal.”
  • The Los Angeles Times, June 14, 2009. “For the average American, modern air travel has all the appeal of a root canal.”
  • Northwest Indiana News, February 20, 2014. “… the topic of life insurance has about as much appeal as a root canal.”
  • The Los Angeles Times, March 29, 2011. “I had a root canal, and that was fun” (this was done in a sarcastic manner).
  • Washington’s Blog, August 26, 2013. “the American people would much rather get a root canal or a colonoscopy than bomb Syria.”

At least in the last example, the procedure is considered more desirable than a regional war and on on the same level as a colonoscopy!

And lastly, we have the President of the United States publicly maligning the procedure in his State of the Union Speech seen here:

So clearly, the procedure is believed to be unpleasant. But shouldn’t we all just stop worrying and appreciate root canals for what they do?

How I Learned to Stop Worrying and Love Root Canals

Dr. Strangelove who would not have worried about a root canal

Dr. Strangelove would have loved what a root canal could do (image courtesy wikipedia.org)

While there are different view on this borrowed line from Dr. Strangelove, there is no ambiguity when applied to the root canal procedure. This procedure helps to save teeth and prevents premature tooth loss.

Once you are adequately numb, you feel no pain during the procedure.

So let’s get this straight. You have a broken down tooth, one that you are at risk of losing. A procedure is available, one that does not hurt, that will allow you to save the tooth and not go around toothless!

And despite all the inherent benefits, the procedure is maligned by nearly everyone, including President Obama.

For this Root Canal Awareness week, let’s try to appreciate them. Or, to take inspiration from Stanley Kubrick’s film, let’s stop worrying and love root canals!

 

Redhead Dread Part II

A couple of months ago, I wrote an extensive blog post about my experiences as a general dentist treating redheads.  I called it Redhead Dread to suggest that redheads dread going to the dentist.  The post was based upon research which found that individuals with red hair required more local anesthesia than non-redheads.  A natural conclusion from that research was that redheads would avoid dental care and/or be fearful of the dentist because of a greater likelihood of a past, painful experience in the dental chair.

Joan on Mad Men is a Redhead - does she dread the dentist

Joan (Christina Hendricks) plays a sassy character on Mad Men. But would she secretly dread a trip to the dentist? (image from fanpop.com)

A research paper released just last month by the Journal of Endodontics detailed the findings of a well designed study which looked at the effects of dental local anesthesia on women with red hair.  This study had a control group of women with dark hair in order to observe the differences. Some of the findings were surprising. Key conclusions were:

  1. In standard injections for the lower teeth using lidocaine (not novocaine), there was no difference in the success of the local anesthesia between redheads and dark haired females.
  2. Redheads felt more pain on needle insertion than dark haired females.
  3. Redheads experienced “significantly higher levels of dental anxiety” when compared to dark haired females.

Considerations for Dental Patients

The first conclusion stunned me, as it contradicted both previous research as well as my own experiences treating dozens of redheads over the past several years.  This was a well designed study but there was a relatively small number of study subjects.  Could the small number of participants explain the unexpected response? Possibly.  But I am not going to doubt or second guess the authors.  Nevertheless, a follow-up study with more participants would be beneficial.

In my own observations as a general dentist, conclusions 2 and 3 are closely linked and were expected. The anticipation of pain can make anyone, regardless of hair color, either amplify a minor pain stimulus into a very painful one, or create a perception of pain when no pain should have occurred.  Stated another way, an expectation of pain can create pain out of nowhere!

Because the first conclusion was a surprise, I do expect there will be additional research on this topic, which I will write about. Until then, we can conclude:

Redheads will have greater anxiety when it comes to receiving dental care. If you are a redhead, don’t be afraid to tell your dentist about any fears you may have!

Redhead Dread

Do redheads dread a trip to the dentist?

Redheads dread the dentist due to resistance to local anesthesia

Redheads. Image courtesy The New York Times

When I stumbled across this article in the New York Times back in 2009, the conclusions seemed eerily familiar.  In my own personal experiences as a dentist in Orange, CT and elsewhere, patients with red hair seemed to be more apprehensive regarding dental care, and also seemed to have the dreaded “well, it looks like you’re not quite numb enough with the first shot, let me give you a bit more” phenomenon occur to them with much greater frequency than patients with darker hair and complexions.

As much as I would like to delve into the true scientific details, those facts go beyond the scope of this post.  But to summarize, redheads have a mutation (basically a change in their genetic makeup) that produces red hair and fair skin.  But that same mutation also affects receptors in the brain that govern pain perception.  Although the exact mechanism is not quite fully understood, studies show that redheads have resistance to lidocaine.  Lidocaine is the most commonly used dental local anesthetic used in the United States. Chances are, when you visit the dentist, and get “The Shot”, you are receiving lidocaine.

So if redheads have resistance to lidocaine, then they are more likely to feel pain during a dental procedure.  But does that translate into more dental anxiety?  Of course.  You don’t need published research to reach that conclusion!   However, in medicine and dentistry, we do like to have our conclusions backed up by sold research.  A 2009 article by the Journal of the American Dental Association did confirm that redheads have “increased dental-care anxiety” and exhibit “avoidance of dental care.”

As a practicing dentist, I always look at research and then ask myself how the findings apply to my patients, either past, present, or future.  This is true not just with this specific research finding but with all the developments that are continuously occurring in dentistry.  A lot of research doesn’t immediately apply. However, this is one case in which the findings have immediately impacted how I approach my patients – specifically patients with red hair.

Lidocaine also known as xylocaine is a dental local anesthetic used in the United States

Dental Carpule of Lidocaine with epinephrine. Redheads have a documented resistance to Lidiocaine.

No dentist is perfect and can get 100% of the patients 100% numb with the first injection.  Any dentist that claims that is lying. There are too many factors that come into play.  As a dentist, it is tempting to find something or someone to blame when your patient does not get numb with the first injection.  Blame the assistant!  The anesthetic must be expired!  The patient moved!  The sun was in my eyes!  The sun was in the patient’s eyes!  It was a full moon last night!  This happens to all dentists and to all patients – independent of hair color.

However, upon thinking back on my own patients who were “tough” to get numb, a disproportionately large percentage had red hair and fair skin.  These patients seemed to require 2 to 3 injections to get numb.  Another observation is that these patients always knew they would need more.  They were the first ones to say “Hey doc, I always seem to need 2 or 3 shots every time I get a cavity filled.”  But they never knew why they needed more local anesthetic.

In my experience, if you know a patient is going to be a challenge to effectively anesthetize, administering extra local anesthetic right off the bat is the best solution. The patient appreciates it.  The second injection, if done properly, will rarely hurt, and will almost guarantee that the patient does not feel any part of the procedure. Since this article was published in the New York Times in 2009, I’ve told numerous redheads about it.  Upon telling them, they nearly universally have an expression of “Wow!! Now I finally understand why I’ve always felt pain and dreaded coming to the dentist.”  And from then on, their fears are reduced, permanently.

So how do we approach redheads who avoid care because of past negative experiences?  This is a lot more challenging! Most redheads are unaware that their genetics are pre-determining them to have more pain in the dental chair (unless more local anesthesia is administered).  So they must be informed of this. Simply informing anxious patients of this genetic phenomenon and how we address it is enough for many patients.  More severe cases of dental anxiety require different approaches.  I have training in sedation dentistry which has allowed me to treat patients who have moderate to severe dental phobias. This has allowed me to personally treat hundreds of patients too scared for “regular dentistry.”  But unfortunately, very few dentists have the training, equipment, and staff to do sedation dentistry safely. I will try to describe other techniques in a future blog post.

Many redheads still do dread the dentist, but now they don’t need to anymore.  There are many dentists out there equipped with this knowledge helping redheads overcome their anxieties, one patient at a time.