Teethcore is a surreal internet aesthetic that uses the imagery of human teeth as its central visual motif. Emerging from Tumblr in the mid-to-late 2010s, it is a specific offshoot of the Morute ("morbid cute") and Gurokawa ("grotesque cute") scenes. The aesthetic is defined by its practice of decontextualizing teeth, presenting them not as parts of a body, but as strange, uncanny objects for art and decoration.

The core of the aesthetic lies in the juxtaposition of the clinical, grotesque, or visceral nature of teeth with sentimental or delicate contexts. It often explores themes of body horror, dental anxiety, and a fascination with the macabre, frequently functioning as a form of "vent art" for its creators to express these feelings.

Teethcore developed within the niche communities of Tumblr around the mid-to-late 2010s. It grew directly out of the Morute aesthetic, which is characterized by the blending of morbid and cute imagery. While Morute has a broader focus on themes like death, dolls, and vintage medical imagery, Teethcore isolated and expanded upon one specific element: the tooth.

The aesthetic's creators and followers began to curate and create a distinct visual language centered on the uncanny quality of teeth when they are separated from the body. The practice of collecting and displaying baby teeth, and the folklore of the Tooth Fairy, also serve as inspirations, often reinterpreted through a darker or more surreal lens.

The visual style of Teethcore is defined by its unique and often disturbing use of teeth as artistic objects. The aesthetic is not about depicting mouths or smiles, but about teeth as isolated, collectible, and sometimes decorative items.

A primary motif is the loose tooth. Images frequently feature collections of teeth, often arranged in artistic or ritualistic patterns like hearts, pentagrams, or circles. This is often taken a step further with the creation of teeth-based jewelry, such as earrings and necklaces, or by placing teeth inside sentimental objects like lockets or music boxes. This act of turning a biological object into a piece of art or a treasured keepsake is central to the aesthetic.

The color palette is often stark, combining the clinical whites, creams, and pinks of teeth and gums with darker, grungier tones. The overall atmosphere is surreal, uncanny, and can range from delicately creepy to overtly grotesque, depending on the artist.