Hadn't thought of dental floss cutter, but DO have one of those Clover round cutters. One friend uses the fold-over ones & has traveled w/ them for years. I had a really good pair taken away w/ tiny points, so I don't put any in my carry-on now. I've never been questioned about the needles - just roll it up in my fabric or cross-stitch. Mostly I read in airports now & leave my small sewing projects in the suitcase! I wouldn't dare risk a big project in my luggage, though.