How do I tell my family I don't want presents for Christmas, but something a lot different?

I'm 21. I don't want an Ipod or a coat or a camera... I want them to help me go to the dentist.I havent been in 2 or 3 years. Being a student I never have enough money, and I don't have dental insurance. I can't afford it. Since my dad was unemployed for the past 2 years, I have paid for my own student health insurance out of my savings for 2 years straight that does not include dental. (I sure am glad I had that money. The only thing is that I thought when I was keeping my money rather than spending it on trips and stuff with my friends like my sister and most other teenagers, I thought the money would go toward school and good things. So far its been health insurance, car repairs, and my yearly eye exam and contact supply since my parents have had no money for ages). Now they have a little money since my dad got his job back, but everyone, including my extending family, seems to think I want gifts and they won't hear of anything else. I want to go to the dentist and get a cleaning. I also have impacted wisdom teeth that cause me pain from time to time. Help.... :(
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Either ask them for the receipts of everything they plan to get you, or just ask for cash. Either way, look for your local dentistry school - they often offer discounted dental work if you're okay with having a student do it.
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