caught in the middle

My ex-wife took my son to the dentist for a procedure. The dentist broke his tooth in the process which caused him to need a specialist. The dentist told my ex-wife that since the dentist broke the tooth, the deductible had been paid by my ex-wife and the insurance had already paid for the first procedure, he would pay for the price of the specialist. So the dentist's office set up an appointment to see a specialist he knows. After several months the specialist office contacted me (the insurance coverage is in my name through my job) telling me I owe them $1,400.00. I had contacted my ex-wife and she called the specialist office. The specialist's office said it just my take some time for the dentist to send in the paperwork and that they take care of it. Now I have recieved an affidavit for a wage deduction order for this. What steps can I take to have the dentist pay this specialist or be responsible for the bill? I really would like to enjoy my christmas with presents for my kids then to have nothing to give them.

You may sue the dentist in small claims if need be.

Were you sued by the specialist in the case; there cannot be a wage deduction otherwise normally?