So, my dentist is encouraging me to do Invisalign to straighten my lower front teeth. I have a bit of crowding in my lower jaw, and one of my incisors slightly overlaps its neighbor. While I don't doubt that having straight, uncrowded teeth would improve the ease of keeping them clean and tartar-free, I'm reluctant for two reasons.
The sensible reason is that by far the biggest improvements in my oral health have come from just being more consistent about brushing properly, flossing, and using antiseptic mouthwash. While I've come a long way on all these habits, I think that maybe I'd be better off investing more time and energy in getting even better at that, rather than spending money on orthodontics.
The unsensible but far more powerful reason is that I spent a goodly chunk of my young life wearing braces and a headgear to correct an overbite. And the thing that got me through the worst parts of the experience was the promise that "when you grow up you won't have to do this any more." (And when I turned 18, I ceremoniously packed up my retainer and stuck it in a drawer and never wore it again. I was a horribly literal child.) And even though the rational part of my brain knows that Invisalign would not be nearly as dreadful for a whole host of reasons, just the thought makes my inner twelve year old howl, "Nooo! You promised I wouldn't have to!"
Normally, I have great respect for my inner twelve year old, but in this case, I think her judgement may be suspect.
On the other hand, I also think my dentist's judgement may be influenced by the prospect of getting to sell me expensive orthodontic treatments.
It's probably too much to hope that someone's actually done a good study to look at whether people who get modest tooth-crookedness corrected actually experience better dental health outcomes in the long term, but I'll have to hie me over to PubMed and have a look.