A surgical instrument includes an ultrasonic transducer, a shaft defining a longitudinal axis, and an end effector at a distal end of the shaft. The end effector includes an ultrasonic blade driven by the ultrasonic transducer to treat tissue with ultrasonic energy. A tissue treatment portion of the ultrasonic blade includes a linear blade region extending parallel to the longitudinal axis, a curved blade region extending distally from the linear blade region along a curved path that deflects laterally from the longitudinal axis, an upper treatment side, a lower treatment side, a first lateral side having a first sweeping side surface, and a second lateral side having a second sweeping side surface. The sweeping side surfaces define respective first and second side edges of a transverse cross-section of the tissue treatment portion, and are configured such that the first and second side edges are parallel to one another.
