Defining the Morphology and Distribution of the Alar Fascia: A Sheet Plastination Investigation

Objectives: This study aims to delineate the morphology, integrity, and distribution of the alar fascia using dissection and E12 sheet plastination. This is the first study that employs E12 sheet plastination to investigate the alar fascia and its adjacent potential spaces. Methods: Twenty-nine manual dissections and 3 sets of E12 sheet plastinations were used to examine the posterior pharyngeal region for the architecture and distribution of the alar fascia. Specimens were examined from the inferior nuchal line to C6. Results: The alar fascia originated as a well-defined midline structure at the level of C1 and could be identified down to C6. There was no evidence of the alar fascia between the inferior nuchal line and the base of the skull. Notably, the alar fascia permitted resistance to manual traction. Conclusions: E12 sheet plastination allowed for visualization of the alar fascia's superior attachments within the deep cervical region. Resistance to traction suggests that the alar fascia may be more than just a loose fibroareolar matrix. The findings in this study suggest an alternative point of entry into the danger space. Understanding the continuity of this fascial layer is critically important with regard to the pathophysiology of deep neck space infections.