Dermatological cosmetic combination treatments with high intensity focused ultrasound, dermal fillers, fat-reducing compounds, cavitation-prone fluids, and/or septa dissection are provided. A HIFU therapy system can include an imaging system, methods adapted to alter placement and position of a line focus band therapy, multiple simultaneous cosmetic ultrasound treatment zones in tissue, and dithering ultrasound beams from a transducer to alter placement and position of multiple cosmetic treatment zones in tissue. The HIFU systems can include a hand wand, removable transducer modules, and a control module. The dermal fillers can include hydroxyapatite. The fat-reducing compounds can include adipocytolytic compounds, pentacyclic triterpenoid compounds, proapoptotic compounds, compounds impairing differentiation of pre-adipocytes, and combinations thereof. The cavitation-prone fluids can include molecules dissolved in fluids, ethanol, glycerin, and ethylene glycol. The septa dissecting can include using a cutting blade and/or cavitation HIFU. The cosmetic treatment system may be used in various cosmetic procedures, such as treating cellulite.