Just to add to my previous post on tongue piercings and the effects they can have on the gums.  I see this too often in my clinic.  Check out the photo below.  It is taken of the lower front teeth from behind (tongue side of teeth).  Notice the tooth in the middle of the picture; the gingival attachment (gum level) is lower.  What does this mean?  Less gums, means less bone support, less holding this tooth in.  This patient is under 25 years of age!

Check out this article from the JCDA.