Making the decision between using a blunt flexible micro-cannula or a sharp hypodermic needle is a choice every aesthetic practitioner makes on a patient-by-patient basis. A cannula is a thin flexible tube like a needle, but longer, with a blunt tip. Since a cannula cannot puncture the skin, a needle is used first to make a puncture through which the cannula is inserted. Since a cannula is much longer than a needle it can reach further and treat several areas of the face at once. This means less needle pricks.
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Sometimes only one or two entry points are needed to treat an entire face. A single entry point and blunt tip minimises potential trauma or bruising. In addition, there is less chance of inadvertently injecting filler into a blood vessel which can cause a serious complication called vascular occlusion.
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A cannula is blunt, and a skilled doctor shouldn’t need to use force as it glides over or under structures like blood vessels or nerves. This allows for a more controlled and measured administration of filler or biostimulator. Needles are sharp and precise. The needle punctures the skin and reaches as many tissue planes of the face as required to get to exactly where one wants the product to be laid. With a needle one can get better projection and lift than with a cannula. The cannula fans the filler in flat layers which is better for contouring. A needle is more precise than a cannula and therefore great for delicate work where control and accuracy are required e.g. smokers lines where a light hand is required to deliver tiny amounts of product quite superficially. In this instance, a cannula simply wouldn’t allow for the same level of control.
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A skilled injector will use both cannula and needle, because they work in different ways and offer unique benefits. Both tools are advantageous in certain areas of the face and for different applications. One is no better than the other.