Osteomeatal complex (OMC) connects
Ans. a (Nasal cavity with maxillary sinus). (Ref. ENT secrets 3rd ed., 100-107)Osteomeatal unit/complex (OMC) confluence# OMC is the normal aerated channel which provide airflow & mucociliary clearance for sinuses.# Anterior ethmoidal air cells, maxillary & frontal sinuses drain into it.# It is the cross road for drainage of most paranasal sinuses.# It is the key area for pathogenesis of chronic sinus diseases.# The concept that obstruction of OMC results in ethmoid, frontal & maxillary sinusitis is fundamental to FESS# Well identified on coronal CT with patient prone & head hyperextended (Coronal CT).# Thus, components of OMC include:# Middle meatus# Maxillary sinus ostium & infundibulum# Anterior & middle ethmoidal air cells ostia & ethmoidal infundibulum# Frontal recess/frontonasal duct# Bulla ethmoidalis# Hiatus semilunaris# Uncinate process# Sphenoethmoid recess & superior meatus (included by some authors)# Uncinate process is thin, curved lamina of bone from the lateral side of ethmoidal labyrinth that forms a portion of lateral nasal wall. It projects downwards & backwards & ranges from 1 to 4 mm in height and 14 to 22 mm in length. Superior edge of uncinate process is free and forms medial boundary of hiatus semilunaris.# Ethmoidal infundibulum is a trough shaped air space that is below bulla & above & lateral to uncinate process. It receives drain from anterior & middle ethmoid air cells & frontal & maxillary sinuses. The infund-ibulum may be narrowed if there is Concha bullosa &/or large Haller's cell (pneumatized middle turbinate).# Hiatus semilunaris is curvilinear opening of lateral wall that is above uncinate process & below the bulla ethmoidalis. This opening separates uncinate process from ethmoidal bulla & serves as connection between infundibulum & middle meatus.# The middle ethmoidal air cell produces a round swelling called bulla ethmoidalis on lateral wall of middle meatus.# Onodi cells are most posterior ethmoidal cells that surround optic canal.
Nasal cavity with maxillary sinus
Nasal cavity with sphenoid sinus
The two nasal cavities
Ethmoidal sinus with ethmoidal bulla
Nose and PNS