Introduction Black triangles, also referred to as open gingival embrasures, are triangular spaces that may appear between adjacent teeth near the gumline when the interdental papilla does not completely fill the embrasure. Although often considered an esthetic concern, these spaces can contribute to food impaction, difficulty with oral hygiene, increased plaque retention, and, in some individuals, alterations in speech. Black triangles are not caused by braces or aligners. In

Orthodontic treatment with clear aligners is planned using digital software to design a sequence of aligners intended to move teeth and coordinate the bite in staged increments. Despite detailed digital planning, tooth movement does not always occur exactly as predicted. Variability in biological response, aligner fit, and patient wear can result in differences between planned and achieved tooth positions. For this reason, refinement aligners are commonly incorporated into al