I am already 23 years old and I am still missing my two upper front teeth. I do not have adult teeth to replace them. They're not in my either. I am also missing a few of my adult teeth at the back. My baby teeth on those areas were really small and looked terrible. My smile is kinda bad because of the gaps I have in between my teeth. The dentist suggested I should have the baby teeth extracted and put in. I declined because I can't afford it for now. He said they could cause some problems later if left in. Three weeks ago, my first and second baby molars on the bottom left side started aching really bad. The gum underneath the first molar has turned dark. Is the tooth dying? I was wondering what you would suggest to replace them besides implants. My chewing ability will be affected once I lost these teeth. My friend said not to have the teeth pulled until they get so worn down. Her dad had several teeth that didn't have adult teeth behind them but was able to keep them until his 50's. I am really hoping I can keep mine that long so I won't have to get implants. How long will baby teeth last? What can cause adult teeth not to develop?