I have a cross bite and my center's don't match -- I'm 25 and just got Damon's. I do have jaw problems, which was why I got braces a little over 4months ago. I have SEVERE TMJ/TMD and chronic migraines, which the braces have reduced significantly.
My recommendations would be to go with what you think will work best in the long run. If cosmetic issues are of little concern, then focus on getting his teeth and bite correct. A crossbite can also have other complications, including problems with speech and keeping the teeth clean (if there is crowding). I have trouble chewing correctly and had cavity problems because my teeth were all getting knocked up.
Damons are fairly easy to keep clean, as there are no ligs, and the brackets are smaller. I go to the hygenist once every 3 months and I brush as often as I can or *remember*.
In terms of helping your son, brushing after everything he eats will help and encourage him NOT TO SNACK. Flossing is something he will have to learn how to do, however a water pick can help to some degree (but is not the same as flossing). With braces, flossing can be tricky and can hurt more because teeth are moving and are loose.
If you know he is going to be getting braces, help him now by getting him used to eating everytime he eats ANYTHING. Help him floss at night or teach him how to. I have worked with special needs before and I have learned that teaching by example helps the most.
- brush your teeth everytime you eat, as well as your son (carry your tooth brush with you and have your son carry his OR carry his for him/ have the teacher at school keep one for him within reach)
- floss your teeth every night when your son flosses
- both of you decrease your sodas and sugar intake, as well as snacking, so you don't have to brush as much
- start getting your teeth cleaned every 6months or every 3 months if you know you will be going the braces route so he can get used to being in the office that often
- use plaque tablets to help him learn where to brush and how to brush
- start eliminating foods that would be bothersome in braces, so the transition to not eating forbidden foods will be easier