The pterygopalatine recess of the superior nasal meatus.

The pneumatizations surrounding the pterygopalatine fossa (PPF) and closely related to the sphenopalatine foramen are anatomically variable. During the assessment of a cone beam computed tomography of a 64-year-old male patient, we found bilaterally a previously unreported anatomic variant. This was represented by a lateral or pterygopalatine recess (PPR) of the superior nasal meatus which extended in the anterior wall of the PPF and protruded within the maxillary sinus to determine a maxillary bulla.

Anatomic variation in the pterygopalatine angle of the maxillary sinus and the maxillary bulla.

Bulges of the most posterior ethmoid air cells into the maxillary sinus were termed maxillary bullæ by Onodi. With few exceptions, they have since been ignored by anatomists through time. Likewise, Sieur cells-the spheno-ethmoido-maxillary air cells-are uncommonly found in anatomical texts.

Regenerative potential of human schneiderian membrane: progenitor cells and epithelial-mesenchymal transition.

An innate osteogenic potential of the Schneiderian membrane (SM) is progressively assessed in studies ranging from non-human species to human subjects. It has relevance for endosteal placement and osseointegration. Nestin-expressing osteogenic progenitor cells are allegedly involved in bone formation and remodelling.