Anterior Nasal Nerves: A Cadaveric Anatomic and Immunohistochemical Analysis.

Abstract

Sensory and autonomic nerves supply the sinonasal mucosa and contribute to chronic rhinitis, rhinosinusitis, and craniofacial pain. While posterior and posterolateral nasal nerves have been studied anatomically and histologically, nerves supplying the anterolateral nasal wall (ALNW) have been incompletely studied. The purpose of this cadaveric study was to investigate the ALNW's nerve supply. Sixteen fresh cadaver heads were dissected. First, six heads underwent unilateral ALNW dissection to harvest nerves coursing through the bony ALNW, and these were termed anterior nasal nerves (ANNs). Specimens were formalin-fixed, sectioned, and stained with hematoxylin and eosin, as well as for sensory or autonomic neuropeptides and enzymes. Nerve biomarker presence/absence was recorded. Next, 10 heads (20 sides) were utilized for ALNW mucosal area measurement and dissections. Bilateral subperiosteal dissections were performed to count nerves coursing from the ALNW and anterior portion of the inferior turbinate (IT). Of the six ANNs analyzed immunohistochemically, sensory and autonomic nerve markers were identified in each ANN. The other 10 cadavers all had ANNs coursing from the bony ALNW, with significantly more ANNs coursing through the bony ALNW superior to the IT-ALNW mucosal junction (p = 0.001). ANNs were identified in all cadavers, with more supplying the ALNW than the anterior portion of the IT. Sensory and autonomic nerve markers were identified in the ANNs. Future studies should explore the relative contributions of sensory versus autonomic dysfunction in different rhinologic conditions, and whether these aberrations differentially affect the anterior versus posterior nasal cavities.