Rare Anatomic Variation: Pneumatized Secondary Middle Turbinate.

The nasal turbinates adhere to the lateral nasal wall and are subjected to various morphological variations. A common variation is concha bullosa, the pneumatization of a nasal turbinate. Another possible variation is the secondary middle turbinate (SMT) which originates from the lateral wall of the middle nasal meatus. Pneumatized SMTs were previously found only twice in Computed Tomography (CT) studies. It is hereby reported the third such evidence, gathered in a 44 y.o. male patient which was scanned in Cone Beam CT (CBCT) for routine dental medical procedures. In the present case the superior turbinates were pneumatized and were found bilateral SMTs. The left SMT was unpneumatized and projected medially and the right SMT was pneumatized and projected infero-medially. The right pneumatized SMT was communicating through a narrow isthmus with the ethmoidal bulla; beneath these two, a large ethmoidal infundibulum opened medially through a narrow semilunar hiatus. Such extremely rare anatomic variations could impede on the normal drainage of the ostiomeatal unit and could lead to inadvertent surgical corridors if they are not documented in CT or CBCT.