Compartmentalization of the human cephalic parapharyngeal space: a scoping review

The existing literature tends to describe the division of the cephalic parapharyngeal space into its prestyloid and poststyloid compartments by relying on either the tensor-vascular-styloid fascia, the styloid diaphragm, or one of many other musculofascial structures, while disregarding the existence of the rest. This scoping review is aimed at integrating these widely differing anatomical descriptions to achieve a more complete understanding of this complex region.

In accordance with the PRISMA-ScR guidelines, online databases were used to identify scientific publications that described the compartmentalization of the cephalic parapharyngeal space. 202 studies were deemed eligible for review and were subsequently categorized according to what anatomical structure they considered to compartmentalize the region.

The anatomical structures most frequently considered to be the dividing boundary between the prestyloid and poststyloid compartments were the tensor-vascular-styloid fascia (in 43.6% of reviewed studies) and the styloid diaphragm (in 30.7%), followed by the styloid process on its own (7.4%), the styloid muscles (5.9%), fascial condensations (4%), the styloid process and the tensor veli palatini muscle (2%), the stylopharyngeal aponeurosis (1%), the stylohyoid ligament (0.5%), and an imaginary plane (0.5%).

We propose a more comprehensive description of the region considering the coexisting musculofascial structures that subdivide it, with the styloid diaphragm coronally dividing the cephalic parapharyngeal space into poststyloid and prestyloid compartments, and the latter being further divided by the stylomandibular membrane and the tensor-vascular-styloid fascia into the parotid, paramasticatory, and paratonsillar spaces.