A system for delivering a therapeutic agent to a patient's ethmoid sinus cavity includes an injection device. The injection device includes an elongate member having a proximal end and distal end at a lumen extending between the proximal end and the distal end, the distal end of the elongate member comprising a sharpened tip or needle, the elongate member having sufficient columnar strength such that advancement of the sharpened tip or needle into the ethmoid sinus cavity, the elongate member does not buckle. The system further includes a dispensing device adapted to hold the therapeutic agent, the dispensing device being configured for coupling to the proximal end of the elongate member.