question about something under my tooth

A few weeks ago,  i noticed under one of back teeth that the gums were starting to recede, and a lot of more of tooth was showing. It does not hurt at all or anything. Well, when i went to the dentist today, he said it looked ok, but it still didnt look completley perfect to him. There is no pus coming out of it or anything. It just seems that the gums went away. He did not give me a definate answer on what was wrong though?

Could you please tell me what this probabaly is?

[Jerome Tsang, DDS]

There is some debate as to whether bone loss and gum recession is a natural process over time or a disease driven process.  If you're quite young, I would assume that if there is no pathology (as in disease), it could be due to toothbrush trauma.  Are you using a hard bristle head toothbrush and brush hard?  You may want to switch to a soft head brush and try to brush more gently but thoroughly.  Its important to brush all the surfaces of your teeth but its not necessary to brush hard.  Plaque will come off easily with brushing.  The teeth can withstand the hard bristles but your gums may not.

Hope that helps.