The modified Lothrop procedure or frontal sinus drill-out is a completely i
ntranasal technique that creates a common frontonasal communication to allo
w drainage and ventilation of the chronically infected frontal sinus. It is
an effective alternative to the classic frontal sinus obliteration. The mo
dified Lothrop is usually performed on an outpatient basis, leaves no exter
nal scars, provides excellent visualization of the frontal sinus in the pos
toperative setting, and yields a high cure rate in chronically infected pat
ients.