Type 1 frontal recess cell (Fig 1): They are defined as single anterior ethmoid cells
within the frontal recess sitting above the agger nasi cell.
Posterior Ethmoids: A small opening was made through the ground (basal) lamella into the posterior ethmoid cells
HALLER CELLS: Haller's cell is the pneumatization of the anterior ethmoid cells
into the roof of the maxillary sinus extending into the floor of the orbit.
1) From within the nasal cavity, the drainage pathway of the posterior ethmoid cells
is sometimes seen as a well-defined opening, or ostium, into the superior meatus.
Ariyurek et al studied 52 patients with normally aerated posterior ethmoid cells
who underwent CT examination prior to endoscopic sinus surgery.
As the dissection progressed, both of these ostia were found to open into the posterior ethmoid cells
Partial multiphase skeletal scintigraphy and single-photon emission CT of the cranium showed increased bone metabolism in the area of the right frontal bone, starting in the ethmoid cells
in the roof of the orbit and extending slightly to the left (figure 2).
However, computed tomography (CT) identified a homogenously enhancing soft-tissue density that involved the right middle and posterior ethmoid cells
and the entire sphenoid sinus.
3) The anterior and middle ethmoid cells
begin as evaginations from the nasal cavity into the middle meatus at about the third month of fetal development.