@stellabelle
I'm 60 and have perfectly good teeth. I've seen the dentist about 5 times in my life. I hate the whole experience so I avoid it entirely. So yes I'd agree that regular checkups are not needed when your teeth are fine. If anything went wrong, you'd soon feel it, so just go when you need it.
That's all well and good, but many dentists will de-register you if you don't attend twice a year. Got to bleed you dry of as much money as they can eh? 
Funnily enough, I don't know ANY other profession who does this - INSISTS you see them (and pay for the 'privilege,) at LEAST twice a year, or they will boot you off their register (so they can sign up new gullible mugs who are daft enough to pay for shit they often don't need doing people.)
This doesn't happen with opticians, doctors surgeries, chiropodists, hairdressers, hospitals, chiropractors, or general clinics, or ANYWHERE. Only DENTISTS.
Why are dentists allowed to get away with this? 
And by the way, the small handful of people fervently defending dentists as perfect saints who can do no wrong (and the couple of posters claiming to be dentists, who say they are only trying to HELP people, and they are NICE;) you can keep chanting that mantra til hell freezes over.
But as I said earlier in the thread, all of the people on this thread (and there are a LOT,) posting bad experiences, and negative opinions about dentists, cannot ALL be wrong.
Many people have had bad experiences with dentists, (and hygienists,) and they are entitled to say that, and they are not going to take anything back that they have said, (no matter how NICE you say you - as a dentist - are.) So suck it up buttercup.
I also don't believe in - or see the point of - dental hygienists. I think they are a pointless, money-making scam. And no matter how much you clean and scrub and floss your teeth, they will ALWAYS find fault with them, and poke and dig to find a salt-grain sized piece of plaque to wave in front of your face.
Then they will spend 10 minutes prodding and poking away at your teeth with floss, pulling out nothing, and leaving you with irritated nerves for weeks on end. Gotta justify charging that £50 eh? 
@LeaveBeforeTheLightsComeOn
Oh and if dentists/orthodontists had done their jobs properly then my teeth and health, including mental health, would be in a lot better shape than they are.
Yep this. I think (some) dentists have a LOT to answer for. It's almost like they deliberately allow peoples teeth to stay/get a bit shit, to give themselves oodles of extra work/extra income in the future... 
@Inappropriatefemale it's OK, don't worry, we get you.
most of us. And we can see what you're saying. 