Postnatal presence of paraseptal cartilages in humans: a description of morphology and size

Anatomical position of the vomeronasal organ in postnatal humans

In the last decade or so, there has been a renewed interest in the adult human vomeronasal organ (VNO). Studies have yielded sometimes disparate findings about the microscopic structure of the organ and its supporting tissues. Such varied descriptions may be due to examination of different regions of the VNO, individual variation of VNOs among humans, or the presence of multiple, non-homologous structures that bear false resemblance to the human VNO. A histological description of the spatial relationship of the human VNO to other nasal septal elements is needed to ensure that all investigators are examining the same regions and homologous structures. Histologically sectioned nasal septa from, 22 human cadavers (1 child, 21 adults) were examined grossly and by light microscopy for the VNO. Using histological sections, the position of the VNO relative to other structures was estimated. Sections containing the VNO were retrospectively compared to scaled photographic slides of the unsectioned septa to identify surface landmarks. Human VNOs varied in anteroposterior and superoinferior position relative to the anterior nasal spine and the nasal cavity floor. In the absence of a visible duct opening, the only reliable surface marker, no consistent surface markings were noted for precise location. VNOs were frequently found superior to swellings associated with the paraseptal and/or septal cartilages. Such findings demonstrate that the human VNO is positionally variable, which may have contributed to previous conflicting findings on presence versus absence. Furthermore, our findings support recent suggestions that the VNO may have been misidentified by some investigators, and that its opening can be easily confused with other structures.

The human vomeronasal organ. III. Postnatal development from infancy to the ninth decade

The large literature on the human vomeronasal organ (VNO) offers little consensus as to its persistence in the adult. We have already documented the existence of the VNO from embryonic day 33 through the neonatal stages. This has now been extended to human adults: 27 cadaver nasal septa, aged 2-86 y, were either dissected or decalcified, serially sectioned, stained and examined. The consistent presence of the VNO is reported as a homologue, in the form of a duct-like structure on the nasal septum at all ages. Also reported are size variability, pronounced bilateral asymmetry, a nonchemosensory pseudostratified ciliated epithelium with considerable structural variation and generally without medial-lateral differentiation, nasal septal glands opening into the VNO lumen, a lack of correlation between postnatal age and VNO size, visualisation of the human VNO with certainty by histological means alone, and a minute opening as its only visible surface feature. The human VNO is a discrete structure that should not be confused with the nasopalatine fossa, the septal mucosal pits or VNO openings.