I Went to the Dentist and My Ear Got Numb

Nothing provokes more anxiety than the idea of getting a shot in your mouth.

But imagine getting a procedure without being numb. As a dentist, I can’t imagine it either. It was dentists understandably – and not physicians – who were responsible for the discovery of local anesthesia. In 1844 Dr. Horace Wells introduced nitrous oxide, commonly known as laughing gas, and ether’s use is credited to Dr. William Thomas Green Morton in 1846.

“Can’t you just give me the gas?”

The answer to this question is yes - and no. For many, the laughing gas used in a dental office setting acts as a relaxant, similar to a glass of wine or anti-anxiety medication. It may even have some amnesiac qualities. For a few, the claustrophobic feel of the mask and the perceived loss of control become intolerable. They yank off the mask and announce that the gas is not for them.

Will the laughing gas get you completely numb though? No. For that, you need an injection.

Dentists are experts at giving injections

We utilize techniques such as:

·         Applying topical gel to numb the gum prior to the injection

·         Warming the anesthetic

·         Injecting slowly

·         Distracting you with shaking or wiggling near the mouth area

·         Distracting you by talking, even if it’s to annoy you because you can’t respond

·         Giving you an object like a stress ball to hold. 

For children – and possibly some adults - setting expectations can be helpful. Just hearing “I’m going to count from 1 to 10. When I’m done, this part will be over.” is comforting. So is giving the child a stuffed animal to hug or having my assistant hold his hand.

What if you’re needle phobic?

Discuss this with your dentist beforehand, preferably during an initial appointment. Chances are you’ll need extra time. A couple of my patients would arrive a half hour prior to their appointment, use the nitrous oxide, and listen to soothing music before we even attempted the injection.

If your dentist seems reluctant to work with you, the relationship may not be the right fit. If your needle phobia is so severe that it prevents you from seeking dental treatment, consider therapy to address the issue. 

In rare instances, adverse events can occur during an injection:

• An electric shock      

In order to achieve effective numbing, the anesthetic must be deposited as close to the nerve as possible. Because your Superwoman Dentist doesn’t have x-ray vision, the needle can inadvertently get too close to the nerve and actually touch it, causing a momentary spark of electric shock. Your dentist will simply adjust the position of the needle slightly to prevent recurrence.

As a bonus, though, you’ll get numb in record time.

• An allergic reaction

By a rough estimate, I’ve probably done 75,000 injections. Not once have I come across a true allergic reaction to the anesthetic. If a reaction did occur, dentists have emergency kits that include an Epi pen. Dental offices also should have an emergency plan that assigns specific responsibilities, such as who will call 911 or wait outside to flag down the arriving paramedics.

• Needle breakage

Again, this is a very rare event that I have never experienced. If this should happen, don’t panic. Today’s three-dimensional x-ray technology will be used to determine the exact location of the broken piece so that it can be retrieved with as little trauma as possible. Your dentist will most likely refer you to an oral surgeon for this.

• The wrong area gets numb

My guess is that this has happened to every dentist. It is mostly due to anatomic variation among patients. Notice I say “mostly” because sometimes this is due to dentist inexperience or error. I admit that I have numbed ears, even eyelids. While it’s disconcerting for a patient to lose the ability to blink, just remember that this is temporary. Once the anesthetic wears off, your blink reflex will return to normal. In the meantime, the eye can be taped shut if necessary.

But let’s assume all goes smoothly and you’re now numb – in the correct location. 

Why are you sometimes so numb that you’re drooling?

And other times not so much. It depends on the location. In the upper jaw where the bone is porous, your dentist can numb just the area around the tooth. Almost always, this will be adequate but occasionally the roof of your mouth – or palate - may need to be anesthetized. No matter how skilled your dentist is, this will sting. The tightness of the palatal tissue doesn’t allow for the anesthetic to easily spread out.

The lower jaw has been and will continue to be the subject of comedians’ jokes. Half your tongue, lip, and face will feel numb. Obviously, the tongue doesn’t need to be numb but it is innervated by a common nerve. If you needed work done on two lower teeth on opposite sides of the mouth, I would recommend you schedule two separate appointments.

The type of anesthetic affects the duration

There are short acting anesthetics for simple, brief procedures. Conversely, other anesthetics will last for hours after the visit. Your dentist may choose to use a long-acting product for an extraction to mitigate symptoms afterwards.  

Ideally you would want the numbness to disappear right after the procedure has been performed so that you can speak, eat, or drink properly. A few years ago, the FDA approved such a drug to reverse the effects of local anesthesia. But before you get too excited, it requires another shot and the reversal is not immediate.

The role of epinephrine

Epinephrine – or adrenaline – is made by your body and produced during a flight-or-fight response. It is also added into local anesthetics to prolong the effects. Epinephrine can sometimes cause you to feel palpitations or your heart to race, especially if the anesthetic has been inadvertently injected into a blood vessel. Although patients may say they’re allergic to the epinephrine, it’s not a true allergic reaction.  

Without the presence of epinephrine, a second injection may be necessary in any procedure lasting longer than half an hour.

Your dentist wants you to get numb

Believe it or not, it’s very stressful for a dentist to work on a patient who’s not entirely numb. Everyone is tense waiting for the next jolt of pain to happen.  

In rare instances, a patient will say, “Don’t give me that. I don’t need the novocaine!” When questioned why, invariably the answer is they hate the feeling of numbness afterwards. Usually the patient is older and may have grown up accustomed to procedures without anesthetic. In fact, probably because the nerve spaces have constricted over time, some do seem to feel pain less. But I still recommend the anesthetic. The procedure will be quicker, smoother, with a better result.

What if you’re still feeling it? 

For starters, speak up, although it should be apparent to your dentist if you’re uncomfortable. Children are especially vulnerable since they may not be able to advocate for themselves. More than one patient has recounted stories from their childhood where the dentist proceeded, saying something like “It’s only a baby tooth. You don’t need to be numb for that!” Nothing could be further from the truth; baby teeth have nerves just like permanent teeth.

 There may be a number of reasons why you’re not completely numb.

• Your dentist didn’t wait long enough

It can take quite some time to become numb, particularly on the lower jaw. Since dental offices operate on schedules, by the time you’re numb, there may not be adequate time to complete the procedure. If your dentist offers to reschedule, he’s doing so in your best interest by deciding not to rush through the process.

• The wrong spot is numb

As I said, it happens. Try to accept that you’ll need a second injection. 

• Infection

When the area is infected or abscessed, the pH in the gum area becomes more acidic and this renders the anesthetic less effective. Treatment may need to be postponed until the infection is managed.

• Psychological factors

Sometimes a patient’s anxiety or fear contributes to the lack of effectiveness.

• Are you a redhead?

Ed Sheeran. Photo creator: Harald Krichel

Due to genetic differences, people with red hair are more difficult to numb. They often require 20 percent more anesthetic. In certain cases, they report never achieving total numbness.

You may experience a tingling sensation as the anesthetic wears off

Children may interpret this as pain and be alarmed by the tingling. If your child is under the age of seven to eight or it’s his first experience with dental anesthesia, watch carefully that he doesn’t unknowingly bite his lip or cheek.

Infrequently there may be adverse events that develop after the anesthesia

• Hematoma

Just like a bruise that may form following a blood draw, a hematoma may develop if the needle causes blood to leak from a blood vessel. Think of it as a blood bruise. Dentists are trained to check that the anesthetic is not being injected into a vessel, but it’s impossible to avoid trauma with the many small capillaries. It doesn’t mean that your dentist has done anything improper. People taking blood thinners may have a higher chance of getting a hematoma. 

Most resolve by themselves. If the hematoma is large or affects your ability to breathe, swallow, or see, seek treatment right away

• Trismus

Trismus simply means a sore jaw muscle marked by an inability to open your mouth to maximum capacity. It’s more likely to occur with multiple injections and usually improves within a few days. Warm, moist compresses will help. If the condition persists, pain medication, muscle relaxants and jaw opening exercises may be indicated. 

• Parasthesia

Altered sensation, or parasthesia, covers everything from tingling, burning, reduced sensation, to no feeling at all. Extremely rare, total absence of sensation is caused by needle trauma to the nerve or anesthetic injected directly into the nerve. Although still rare, parathesia is more commonly caused by injury to the nerve during wisdom teeth extraction or implant surgery. 

The nerve may recover slowly from injection trauma, but parathesias can also be permanent.

Risk is part of everyday life.

The last two years have made this crystal clear. Administration of local anesthetics is second nature to dentists. While it’s prudent to be informed of the infinitesimal serious risks, the benefits greatly outweigh the drawbacks.

Why would anyone NOT want pain-free dentistry?