Angularis nigra
space or gap seen at the cervical embrasure, below the contact point of some teeth, when the interdental papilla does not fully enclose the space, leading to an aperture between adjacent teeth
Angularis nigra, Latin for 'black angle', also known as open gingival embrasures, and colloquially known as "black triangle", is the space or gap seen at the cervical embrasure, below the contact point of some teeth. The interdental papilla does not fully enclose the space, leading to an aperture between adjacent teeth. This gap has many causes including gingival recession, and gingival withdrawal post-orthodontic work. Interdental "black triangles" were rated as the third-most-disliked aesthetic problem below caries and crown margins. Treatment of angularis nigra often requires an interdisciplinary approach, involving periodontal, orthodontic and restorative treatment. Possible treatments to correct angularis nigra include addition of composite resin in the space, veneer placement, or gum graft. Angularis nigra is generally only treated based on the aesthetic preference of the patient (although serious gum recession may warrant periodontal treatment).
Previously, lack of proper terminology to report this condition was an issue, often colloquially termed the "black triangle"; angularis nigra has been proposed as a term to describe the appearance.
There are several risk factors leading to the development of black triangles. Papillae dimension can be changed due to any of the following reasons:
1.
This brief starts where responsible research should: with the source description of “Angularis nigra” as space or gap seen at the cervical embrasure, below the contact point of some teeth, when the interdental papilla does not fully enclose the space, leading to an aperture between adjacent teeth. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the general reference register because the source frames it as space or gap seen at the cervical embrasure, below the contact point of some teeth, when the interdental papilla does not fully enclose the space, leading to an aperture between adjacent teeth. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Jan 29, 2026. The linked authority identifier is Q4764028. None of the 0 selected statements returned an explicit reference.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Angularis nigra” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.