Bunny lines on the nose

The nasalis muscle sits over the side of the nose and pulls upward and inward. Some people recruit it heavily when they smile or squint, and the skin over the bridge is thin, so the folding shows early.

Whether you get them is largely down to how you animate rather than how old you are. I see them in people in their twenties who scrunch when they laugh, and not at all in people twice that age who do not.

This is the part worth knowing before you have anything done. When the frown lines between the brows are treated, some people unconsciously recruit the nasalis to compensate — the expression still wants to happen and finds another muscle to do it with. Bunny lines can appear, or become noticeably more obvious, for the first time.

It is not a complication and it is not a sign anything was done badly. It is a predictable consequence of changing how one muscle group behaves within a connected system. It is straightforward to treat when it happens, and I would rather you heard it from me beforehand than discovered a new line on your face and assumed something had gone wrong.

A very small dose either side of the nose, placed superficially. The technique matters more than the product: the levator muscles that lift the upper lip run close by, and product drifting into them produces a heavy or asymmetric smile that lasts until the treatment wears off.

So this is a small, precise treatment, and it is one where I would rather under-dose and review at two weeks than be bold.

If bunny lines only appear when you scrunch your nose deliberately, and not in ordinary expression, they are not really a problem worth treating and I will say so.

If lines across the bridge are visible at rest, that is usually skin quality rather than muscle — thin, sun-damaged skin holding a crease — and relaxing the muscle will not do much for it. Skin-quality treatment does more.

Nose scrunching is part of how many people laugh. Removing it entirely can make a face read as slightly flat in animation, in a way that is hard to name but easy to notice.

The aim here is softening rather than abolition, and it is worth saying out loud at consultation which of those you actually want.

Bunny lines have three quite different origins, and which one applies changes what should be done about them.

The second is worth understanding because it is nobody's fault and it is avoidable. When the muscles either side of the nose bridge are relaxed, the small muscle across it can take up more of the work — so lines that were never noticeable become noticeable. Treating the upper face as one unit from the outset, rather than region by region, is what prevents it.

The muscles here are small, superficial, and sit very close to the ones that lift the upper lip. A small amount of product in the wrong plane can flatten how the lip lifts on one side — which shows in every smile and is considerably more noticeable than the lines being treated.

That is the entire argument for conservative dosing in this area. The cost of doing slightly too little is a fortnight more with the lines; the cost of doing slightly too much is a smile you do not recognise for three months. Those two risks are not symmetrical, and the plan should say so.

Where the line is visible with the face entirely at rest, softening the movement stops it deepening but will not remove what is already there. The skin itself has to change, and that is a different category of treatment.

• Skin quality treatment — microneedling, or a resurfacing course — works on the collagen underneath, over weeks rather than days.
• A very small amount of a soft, superficial product is occasionally used in an etched line. In this area that is a decision made carefully rather than routinely.
• Time helps. A line that has stopped being creased hundreds of times a day does soften on its own — slowly, over months.

Anyone promising to erase an etched line in one appointment is describing an outcome rather than a mechanism.