The little black triangles that can form between teeth at the gumline are most often caused by a variety of factors. Gum disease, misaligned or missing teeth, and aggressive brushing are the most common reasons black triangles appear. Other factors include the general shape of teeth, orthodontic treatments gone wrong, and bone loss.
The appearance of black triangles is known as gingival embrasure. It is often caused by gum recession which is a common symptom of gum disease (periodontitis). While gums can recede naturally due to age, failure to maintain proper dental hygiene will accelerate this process. Smoking or other tobacco use, as well as a diet high in sugar, starches, and acidic foods will increase the likelihood of contracting periodontal disease. Whether due to aging, poor hygiene, or bad habits, when the gums begin to pull away from the tooth roots, these black triangles can appear.
When teeth are misaligned or missing, a process that can happen naturally due to aging or from trauma to the mouth or face, gaps can form at the gum line. These gaps are often treated with orthodontia, either braces or clear aligner therapy.
On the other hand, gingival embrasures can sometimes be the result of poor or incomplete orthodontia. When the teeth are shifted during orthodontic treatments, gaps can appear causing the appearance of these black triangles. Over the course of the treatments these gaps will come and go, but the goal of orthodontic treatment is to straighten the teeth and close any gaps between them. At the end of a successful orthodontic treatment, teeth will sometimes shift themselves back towards their original positions, re-opening these gaps. For this reason, the final step of any orthodontia is to wear a retainer to keep teeth from moving too much.
Bone loss can contribute quite significantly to the appearance of little black triangles. Bone loss in the mouth occurs most often due to aging but is also a result of periodontal disease or trauma. When the bone that makes up the jaw is damaged, the gums it supports can sink, leaving open space around the roots of the teeth and giving the appearance of black triangles.
Lastly, the shape of teeth plays a large role in how gingival embrasures appear. Rectangular teeth have straight edges and so fit together nicely without any gap. If you have oval-shaped or triangular teeth, any loss of gum tissue will become much more pronounced as the gaps between the teeth at the root is much larger.
There are many reasons the little black triangles may appear between your teeth. It is vital to understand the causes in order to decide what treatment is right for you. Having these gaps fixed soon for both cosmetic reasons and dental well-being promptly is important. Patients often feel self-conscious about black triangles, but the real danger is the bacteria that can thrive in the gaps between teeth. Whether due to bone loss, gum recession, or problems during orthodontic treatments, it is possible to fix these gaps and restore your smile.
If you have black triangles, speak with your dentist about potential solutions (like dental bonding).