Retrobullar recess

The retrobullar recess is a small potential opening (cleft) rather than an actual air cell located superior and posterior to the ethmoid bulla, separating it from the skull base and basal lamella. The ethmoid bulla usually opens posteriorly in the retrobullar recess.

Gross anatomy

Boundaries

• anteriorly by the posterior wall of the ethmoid bulla
• posteriorly by the basal lamella
• superiorly by the skull base
• laterally by the lamina papyracea