The wire keeps poking my cheek and it hurts—I think I have a sore.

As your teeth move, the end of the wire at the back becomes longer and pokes your cheek — if you come to the clinic, we can trim the end and resolve it right away. For first aid before your visit, 1) roll orthodontic wax into a small ball and place it over the poking spot, and 2) if you don't have wax, temporarily cover it with clean cotton from a swab or a piece of gauze. However, if the sore is already deep or an ulcer has formed and eating is difficult, leaving it can let the inflammation worsen, so please don't put it off and come in as soon as possible.