Killian's incision is used for -
"The incision used for submucous resection is known as Killian's incision, whereas that used for septoplasty (at the free margin of the quadrangular cartilage) is Freer's incision". ─Essential otolaryngology.
Submucous resection of nasal septum
Intranasal antrostomy
Caldwell-Luc operation
Myringoplasty