TABLE 1.

Overview of the ultrasound patterns of the different dermal fillers

Pattern	Ultrasound findings
Heterogeneous	Presence of alternating anechoic/hyperechoic images, which that are visualized in the tissue in a heterogeneous way. This pattern is characteristic of healthy skin and subcutaneous cellular tissue. Additionally, it is observed after tissue biointegration of resorbable fillers, like hyaluronic acid‐based fillers. This pattern allows to see those fillers that, due to their chemical characteristics, are not collected and remain diffused into the tissue, causing fibrosis and hyperechoic images to varying degrees.
Fine‐grain snowfall	Presence of hyperechoic images with posterior echogenic shadow. This pattern is characteristic of oily silicone and biopolymers. There is an important infiltration of the tissue, which causes posterior reverberations.
Coarse grain snowfall	Presence of multiple hyperechoic images distributed into the tissue in a homogeneous way, which gives its typical coarse grain snowy appearance. Echogenic shadow is usually lower than in the "fine‐grain snowfall pattern", since the infiltration of the tissue by the material is usually less. This pattern is characteristic of calcium hydroxylapatite and polymethyl methacrylate.
Globular	Presence of cysts, with content of an anechoic nature to a greater or lesser extent, surrounded by a capsule of variable thickness. There is posterior reinforce suggestive of liquid or semi‐liquid content in the cyst, which causes a typical hyperechoic imaging. This pattern is characteristic of polyalkylamides and polyacrylamides (non‐resorbable materials that behave like a Endoprosthesis). In addition, this pattern is also observed in hyaluronic acid‐based filler immediately after their injection.