Chewies can help. Having some aligners feel loose (or tight) is normal. Why? The aligners can sometimes cause the teeth to react quickly, and they will move, causing the aligners to feel loose. Then they will slow down and feel tighter again. It is also normal for some of your teeth to feel loose some of the time as they are moving to their new desired place. This will all go away in time as your mouth heals and adjusts.