Dental Education Lecture: Floss Abuse

Mr. Jan is 71 years old and came to my office last week.  He reported gum swelling and pain in the bottom right jaw for a few days.  We found a large abscess (A) between 1st (1) and 2nd (2) molars on the tongue side.  Fig.1 is biting surface view, whereas Fig.2 is tongue side view.  He also reported that food is often trapped between these two molar teeth.  Whenever this happens, he uses dental floss to remove the trapped food.  However, this time flossing did not alleviate the discomfort and made even worse.

Careful exam shows that these two molars are not aligned very well: while the 1st molar is more toward the tongue, the 2nd molar is more toward the cheek.  In addition, there is a large chip in the front end of the 2nd molar (arrowhead in Fig.1).  Therefore the contact between these two molars is not normal, the basis of food impaction.

Detailed discussion and exam reveals that the patient did not use dental floss properly.  In Fig.2, next to the abscess (A) is a wound indicated by two arrowheads.  This is a cut caused by pressing floss too deep into the gum tissue.  When we have problem of food entrapment, we should seek dental consultation.  Abuse of floss can make things worse.

Please review the following articles for right ways of flossing: How to Floss, Flossing, When to Floss, Why to Floss, and Brush & Floss.

Xin Wei, DDS, PhD, MS 1st edition 10/25/2009, last revision 10/25/2009