This can vary depending on factors such as size of wound, location, width of wound, and surgeon preference. Quite often, dissolving stitches will be put deep into the wound, giving it more strength while the scar forms.
For the top layer of skin, either dissolving or non-dissolving stitches may be used.
Sometimes, the surgeon can use a subcuticular stitch. This is a stitch that runs inside the top layer of skin, so as it dissolves it won’t leave stitch marks. This stitch can’t always be used though.