The onychodermal band is the “natural smile line” of the nail unit, where nail bed epithelium bunches up to pass through  the tight seal of the hyponychium creating a grey line at the edge of the nail bed before the free edge of the nail plate.

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What is the onychodermal band?

The onychodermal band is an area at the edge of the nail bed that looks slightly grey when seen through the nail plate. It is considered to be the ‘natural smile line’. There is a strong seal under the free edge that prevents allergens and pathogens from reaching the delicate nail bed where they can cause infections that will affect the nail and the matrix (where the nail is created). The skin from the nail bed, as it grows forwards, squeezes past this seal and slightly bunches up. This is why it appears to be a slightly different colour

Is having a natural smile line healthy?

Every nail has a natural smile line. It is where the nail grows away from the skin of the nail bed.

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