This article reviews the etiology and treatment of open gingival embrasures or black triangles. An open gingival embrasure or black triangle occurs as a result of a deficiency of papilla beneath the contact point. The treatment of open embrasures may require restorative, orthodontic and periodontal considerations depending on the underlying etiology. The authors reviewed a total of 42 articles including review of literature, radiographic, cross-sectional, and retrospective studies in Ovid search engine using the terms "open gingival embrasure,""interdental papilla," and "black triangle." The studies provided information regarding etiology, diagnosis, and treatment of open embrasures. There are several risk factors leading to the development of open gingival embrasures. These factors include aging, periodontal disease, loss of height of the alveolar bone relative to the interproximal contact, length of embrasure area, root angulations, interproximal contact position, and triangular-shaped crowns. Treatment of open embrasures requires an interdisciplinary approach of orthodontic, periodontic, and restorative treatment. CLINICAL SIGNIFICANCE Open gingival embrasures are complex esthetic and functional problems. An interdisciplinary team approach with the general dentist, orthodontist, and periodontist is critical. Management of open embrasures requires careful evaluation of the underlying etiology.