Dermal filler a substance that is injected into the dermis of the skin and can work improve definition and smooth irregularities. It can therefore be very effective in treating a dorsal nasal hump, making the nose appear straighter. Although there are many different types of fillers, the most popular are hyaluronic acid (HA) fillers. Dermal fillers can have different structures and consistencies that make them more suitable for treatment of different areas. For example, when treating the nose, we use a filler that is firm and smooth in order to shape and define.