sa or on tapping the teeth of the upper jaw, and swelling of the
cheek are rarely met with save in acute inflammation. The complaint of
a bad odour or taste, the reappearance of pus in the middle meatus
after mopping it away and directing the patient to bend his head well
forwards, and opacity on trans-illumination of the suspected cavity,
are signs which strongly suggest an affection of the maxillary sinus.
The withdrawal of pus by a puncture through the thin outer wall of the
inferior meatus of the nose with a fine trocar and cannula will
establish the diagnosis.

The _treatment_ consists in opening and draining the sinus. If the
infection is due to a carious tooth, this should be extracted, the
socket opened up and drainage established through it in recent cases.
If the teeth are sound, and the case is of long duration, the sinus is
opened through the canine fossa and its walls curetted. To avoid the
risk of reinfecting the cavity from the mouth, an opening may be made
into the nose by removing a portion of the nasal wall of the sinus and
part of the inferior turbinated bone, after which the incision in the
buccal mucous membrane is closed with sutures.

Suppuration in the _frontal sinus_ is attended with frontal headache,
vertigo, especially on stooping, and tenderness on pressure,
particularly over the internal orbital angle, or on percussion over
the frontal region. Pus escapes into the middle meatus of the nose,
and if wiped away will reappear if the head is kept erect for a few
minutes. After removal of the anterior end of the middle turbinated
bone, it may be possible to catheterise the sinus and wash out pus
from its interior. The diseased sinus may present a darker shadow than
the healthy one on trans-illumination, or in an X-ray photograph.

The _treatment_ consists in exposing the anterior wall of the sinus,
chiselling away sufficient bone to admit of free removal of all
infected tissue, and establishing efficient drainage through the
infundibulum (Fig. 267) into the nose.

The _anterior ethmoidal cells_ (Fig. 267) are frequently affected in
conjunction with the frontal, and sometimes with the maxillary sinus.
The presence of polypi and granulations, with pus oozing out from
between them, and increasing after withdrawal of the probe, and the
detection of carious bone are significant of ethmoidal suppuration.

The _treatment_ consists in extending the operation for the frontal or
maxillary sinus so as t