In Orbital Cellulitis, which sinus is most commonly involved?

In Orbital Cellulitis, which sinus is most commonly involved?

• A. Maxillary sinus
• B. Ethmoid sinus
• C. Frontal sinus
• D. Sphenoid sinus

Answer: (B)

Spread into the orbit is most likely from infection of the ethmoid sinuses because the medial orbital wall is formed by the lamina papyracea, a very thin bone that lies directly adjacent to the ethmoid air cells. This close proximity allows an infection in the ethmoid sinuses to breach the wall and involve the orbital contents more readily than infections from other sinuses. This is particularly true in children, where the ethmoid air cells form early and create a common route for spread. The maxillary sinus sits below and to the side of the orbit, so while it can be involved in sinusitis, it doesn’t provide as direct a pathway to the orbital tissues. Frontal and sphenoid sinuses are farther from the orbit and typically require more extensive disease to extend into the orbital space, making them less common sources of orbital cellulitis.

Spread into the orbit is most likely from infection of the ethmoid sinuses because the medial orbital wall is formed by the lamina papyracea, a very thin bone that lies directly adjacent to the ethmoid air cells. This close proximity allows an infection in the ethmoid sinuses to breach the wall and involve the orbital contents more readily than infections from other sinuses. This is particularly true in children, where the ethmoid air cells form early and create a common route for spread.

The maxillary sinus sits below and to the side of the orbit, so while it can be involved in sinusitis, it doesn’t provide as direct a pathway to the orbital tissues. Frontal and sphenoid sinuses are farther from the orbit and typically require more extensive disease to extend into the orbital space, making them less common sources of orbital cellulitis.