The present invention provides minimally invasive devices and methods for accessing the sinuses and their surrounding structures for surgery and other treatments. The anterior ethmoid and maxillary sinuses are accessed and treated under minimal anesthesia with little or no postoperative limitation of activity or adverse symptoms. Direct visual verification of the sinuses and their natural ostia is utilized. Other paranasal sinuses may be treated by this method as well. The sinuses, in particular the maxillary and anterior ethmoid, are accessed via a direct anterior to posterior axis and the natural ostia of those sinuses is directly visualized for placement of a guide-free dilator, in the desired location within the natural ostia. That access to the maxillary ostium is accomplished by the anterior transuncinate “keyhole” approach in which a hole is punched in the uncinate process with the described devices according to the described methods. The properly placed dilator is expanded to allow drainage of the inflamed sinus and then withdrawn. An analogous ethmoid bulla “keyhole” approach and subsequent dilation are used for the anterior ethmoid sinus ostia. Pharmaceutical agents may be placed at desired locations in the sinuses using the same access technique.