Does anyone have the same problem as I do?

I'm 22 yrs. old and I still have 3 of my baby teeth. I did have 7 others up until about 5 yrs. ago. I gradually started losing them, and when they would fall out, I had no adult teeth underneath to grow in. So as you can imagine I'm left with gaps all throughout my mouth.And I recently noticed that the other 3 baby teeth left, are also about to come out and their all on the bottom and all beside each other. When I was growing up, I only had 22 teeth grow in, when originally your suppose to have 32. I never got my molors or any of my back teeth. I had x-rays done, and their not even there. Weird I know. So now my only option is to either get dental implants or go the cheaper route and get dentures. All of the dentists that I have been to, cant come up with a solution of why my adult teeth were never there. Does anyone have a suggestion that might help, or any ideas of what might have caused this?