black triangles
Shadowy three-sided shapes
Black triangles are the dark, wedge-shaped gaps that can appear between teeth near the gumline, especially after gum recession or orthodontic treatment.
Dentists call them open gingival embrasures.
The term also refers to triangular symbols used in Nazi concentration camps to mark "asocial" prisoners, and to a category of unidentified flying objects described as large, silent, and triangular.
- hazardsDangers or threats
- warning signIndicator of potential danger
- shapesExternal outlines of things
- symbolsMarks conveying meaning
- warningsAdvance notices of danger
interdental · Area 51 · emblems · gingiva · Roswell incident · periodontal · dentistry · gum disease · missing teeth · dental plaque · alien spacecraft · flying saucer · extraterrestrial contact · close encounters · classified documents · government cover-up · plaque · inflammation