Handling tuition and 529 reimbursements for divorced dad and not claiming dependants

I am paying for both my children's college educations and pulling from a 529 that each one has to reimburse myself. I'm not entirely clear how to claim that expense on my taxes as the 529 income is most definitely affecting my tax burden. The 1098-T is just an information doc and my kids, as adults are entering that on their individual forms. I'm divorced, but they are claimed as dependents on their mother's taxes.