A method is provided that includes inserting a stylet into a greater palatine canal of a subject, the stylet including a proximal rod shaft, having a first diameter, and a distal rod shaft, having a second diameter less than the first diameter, such that a region between the proximal rod shaft and the distal rod shaft is shaped so as to define a shoulder. The stylet is advanced through the greater palatine canal until the shoulder reaches an entrance of a greater palatine foramen, thereby preventing insertion of the distal rod shaft into a sphenopalatine fossa of the subject beyond a depth of the greater palatine canal.