What causes dark triangles between teeth?

It is common to have dark triangles (little spaces between two teeth) before, during or after orthodontic alignment of teeth. With healthy gums and well-aligned teeth that are touching each other in a row, we normally see no spaces between the gum and the teeth. Dark triangles are caused either by the shape of teeth or health/shape of the gum between the teeth.

The shape of the teeth play a critical role in the presence of dark triangles. If teeth are rectangular in shape, their flat sides lay side-by-side with little or no space between them. If the sides are more rounded, or if the teeth are triangular in shape however, the embrasure is larger and more likely to appear as a space (dark triangles) if the gum tissue isn’t ideal (as seen in the picture below).

The other factor related to the presence of dark triangles is the shape and size of gum between the teeth. When we are young, our gums are taller between the teeth and they usually completely fill the embrasures. As we get older, the height of our gum tissue naturally decreases and triangular spaces begin to appear, even between straight teeth in healthy mouths. Teeth that are well-aligned have room for normally shaped gum tissue between them. Crooked teeth often overlap such that there is no room for papilla between them. In these cases, aligning the teeth exposes the fact that there wasn’t gum tissue between them to begin with. For this reason, many patients mistakenly believe that their orthodontist caused the dark triangles. In reality, he merely uncovered the fact that there were no papillae between the overlapping teeth to begin with.

Can the Dark Triangles be Eliminated?

There are two procedures that can be done to help reduce or eliminate dark triangles that exist because of poor tooth shape. First, the shape of the teeth can be changed by placing a veneer or composite filing on them. The other procedure involves reshaping or filing the sides of rounded or triangular teeth so that they are flatter and can be moved closer together. This procedure is officially referred to as “inter proximal reduction" (IPR). It can be performed by your orthodontist who is trained to know how much enamel can safely be altered without causing problems.