I saw an orthodontist, who referred me to a periodontist (gum disease specialist) to see if anything could be done about my "receded gums" (which turn out not to be receded, but I'm jumping ahead) that were causing tooth sensitivity. He gave me bunch of phone numbers, and of the one I wound up calling, the receptionist said "He's not available for quite a while, do you want to see the other doctor in the office? He also happens to be the dean of dentistry at the University of Washington." Woohoo! I said sure.
This doctor was very nice; he checked out my teeth, and then told me:
- I have grooves across the middle of my two front teeth, arched in parallel with the gumline. The doctor told me that this might be due to having had a high fever when the teeth were still developing. If children get very sick while their adult teeth are growing, the teeth stop growing for a little while, and this etches a line. I had always thought these grooves marked my real gumline, and everything above that was recession, but this is a more interesting explanation.
- From what he can tell, my gums aren't receded significantly at all; there is plenty of gum tissue. The problem I'm having is that my teeth are sensitive to acids and touch, sometimes to the point of pain (especially if I eat fruit, lemon juice and grapefruit being the worst, oranges and apples being more tolerable but still problematic). He explained that this is occurring because I'm missing some enamel from the tops of my teeth, exposing the "dentin tubules" which conduct sensation to the nerve. Apparently, blocking the dentin tubules is the key to not having sensitivity, but acids and things like cosmetic whitening procedures tend to clear them out.
- Why am I missing enamel from the tops of my teeth? He thinks I have spent some period of my life brushing too hard with a non-soft toothbrush. Sure enough, (a) I am right-handed and the gumlines are a little higher on the left side of my mouth (which would have been easier to hammer on); (b) the sensitivity is worst on the most promininent teeth, the canines, especially on the left; (c) I know for a fact I used to think soft toothbrushes were for wusses, until sometime after I started college they insisted I switch to soft and I did. The doctor said that he has one spot where the enamel is pretty worn down on some of his teeth because when he was in college someone gave him a natural-boar-bristle toothbrush. The dental world apparently only recently came to understand the importance of soft toothbrushes.
- Why did this problem only emerge when it did, long after switching to a soft toothbrush? Well, I first noticed the problem in early 2001, right around when I was experimenting with raw food diets which can contain a lot of acidic fruit. I suppose at this point I'd been cumulatively exposed to enough acid to start to screw up the dentin.
- What can be done about this? Pretty much nothing. He said that some dentists will offer to apply veneers to the teeth to seal them, but besides the fact that this process is expensive, veneers don't last forever, and the teeth have to be ground down a little to create a surface that the veneers can stick to, so in the end the original problem is worse. He gave me some fluoride gel and said that fluoride treatments can block up the tubules.
- He also said I have a crossbite (my top molars are tilted inward), so referred me to the person who teaches adult orthodontia at UW. I went to see him, and he said, just like the other orthodontist, that I have a crossbite and crowded front teeth, and he wanted to give me braces. He quoted me about $6k and said it would take 15 months. I don't think I'm going to do that. I can chew with my molars just fine, and although I would like my front teeth to be cosmetically straighter it's not a big deal. I know they will get more crooked with time (judging by my dad's teeth), so I will probably do something about it later.
- Also, I don't have to take antibiotics before dental appointments anymore. They used to think you had to do that for the rest of your life after having heart surgery,* but not anymore; now they think after you're well healed you no longer have to. So I checked with the cardiologist I'd seen in Florida and sure enough, I don't have to take those anymore.
So basically I can't eat too much acidic fruit for the foreseeable future. It was good to get the explanation on that, even if I don't like the answer.
* The best explanation I've found for why they have you premed for dental appointments after heart surgery is because the surgery makes your heart somehow vulnerable to infection, and during a dental cleaning, you're both stirring up bacteria in the mouth and also causing some amount of bleeding, so the stirred-up bacteria can get in the bloodstream and potentially stop the heart. Apparently this has happened to people once or twice, and the liability issue resulted in all dentists requiring it before long.