does dermaroller tear the skin?

[skinny]

hello,

i was thinking of purchasing the dermaroller (1.5mm)  but somehow unsure as i can not understand how the needles being on the roller structure do not not tear the skin.. or they do? i mean the needling with single needle or stamp make more sense to me because of vertical down and up movement, but with the roller the needles kind of move inside the skin, so making small tears (wider than the needle diameter) before they actually lifted from the skin but not pricks like stamp or needle or fraxel would do?

hopefully i made myself clear:)

will really appreciate your opinion!

thanks.

[SarahVaughter]

I can understand your concern and you would indeed be right if the skin was made of a relatively rigid material such as aluminium foil over a sponge or something. I think that were one to do such an experiment, one would observe some tearing.

However, the skin is a very pliable organ that, when dermarolling, behaves more like a thin sheet of rubber. When happens is that the needle is inserted under a quite ideal angle a little less than 90 degrees. Before the skin can tear, the sharp tip will have pierced the skin and the motion continues downwards from there, not hampered by the hard epidermis but onward through much softer layers, lubricated even by some blood plasma and the natural oils secreted by the skin. The easiest way out is therefore through the hole just created. Very much less force is required to leave the hole than to make the hole - the only force to be overcome is the suction of the tissue around the needle - and the skin is flexible enough to stretch that fraction of a millimeter. It is much easier for the needle to exit via a ready-made opening, stretching the skin every so slightly than to tear through the epidermis, which would be even harder than to make the prick in the first place.

I'm not saying that tearing is totally impossible. with very aged, thin and inflexible skin for example, 2 mm needles could cause some micro-tearing. The key here is skin flexibility. As long as your skin has a modicum of flexibility, all will be well, especially with needle lengths of 1.5 mm and below. With greatly aged skin or other skin flexibility issues, I would start with shorter needles such as the 0.5 mm first and work my way up, seeing if tearing occurs. However in general, when tearing starts to occur, the first suspicion is bent or blunt needles. The needles would have to be visibly bent to cause this though.

[skinny]

thank you for the reply. this really makes sense:)