Insight 90 — My Method for Pain-Free Local Anesthetic Injection
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Clinical Explanation
Some areas of the mouth are richly innervated, and an injection there is genuinely painful for the patient. For these areas I use a simple three-step method that I have been doing for years.
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1. Vibrate the mirror on the mucosa.
Before the injection, I place the mirror on the mucosa of that same area and shake it. This has a physiological basis, called the "gate control theory of pain". When we touch or shake an area, the touch signal travels along a nerve pathway that can partly block the pain signal from getting through. It is the same thing we do instinctively when we rub a spot we have just knocked. The patient is also distracted and does not feel the exact moment the needle goes in.
Its effect is not the same for everyone, though. Some patients feel a clear difference and some feel less. -
2. Insert the needle superficially and inject only a few drops.
I do not take the needle deep. I go in very superficially, inject a few drops slowly and withdraw the needle. There are two reasons:- The first entry of the needle is felt anyway. But if I go deep on that very first pass, the needle travels its whole path through tissue that is not yet anesthetized. When I first anesthetize only the surface, on the second entry the needle passes through anesthetized tissue on its way to depth.
- Much of the pain of an injection does not come from the needle itself, but from the pressure the fluid puts on the tissue, especially where the tissue is firm. A few slow drops do not create that pressure. That is why a slow injection is always less painful.
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3. Wait about 30 seconds, then continue.
After this pause I go in again and complete the injection. The anesthetic needs a little time to take effect. Thirty seconds is enough for the surface layer to become numb, so the patient feels the rest of the injection much less. -
Summary
Vibrating the mirror to reduce the sensation of pain, a superficial, slow deposit of a few drops, and half a minute's wait for the surface anesthesia to take hold. None of it needs any special device. It only takes a little patience.
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