Use of full sedation for dental surgery in children with autism...?

My 11 year old has autism and is totally non compliant with the dentist beyond a basic cleaning. He has some issues that need to addressed and the only way that will happen is in a pediatric OR under full sedation. Our dentist is wonderful, but we know our insurance company will turn down the full sedation (they only cover it if children under the age of 5). We are planning to appeal as there is no other way to do the needed work. I had been told at one time that since our child has diagnosed special needs that would make working on him in a tradtional way impossible, the insurance company must cover the costs. If anyone has any idea on where to look or a link to a site that discusses this topic, I would appreciate it. We live in MD, in case it is a state by state issue, Thanks so much!