eRadiograph Volume 7: Imaging of Oral Cavity | Page 148
Parapharyngeal Space
Introduction
This is a central fat filled space deep in the face. It is not surrounded by fascia but
surrounded by fascial lined spaces. Since there is no fascial covering and it contains only
fat, it is very mobile and can be easily displaced. Mass lesions in the adjacent fascially
lined spaces displace the fat filled parapharyngeal space. Based on the direction of the
displacement of this space the origin of the space from where the primary pathology is
lying can be determined.
Extent and Anatomy
The parapharyngeal space extends from the petrous apex at the base of the skull
inferiorly to the greater cornu of the hyoid. Inferiorly it is continuous with the fat of the
posterior aspect of the submandibular space as there is no fascia separating the
parapharyngeal space from the submandibular space. As a result pathological
processes can pass freely between these two spaces. The parapharyngeal space lies
lateral to the pharyngeal mucosal space, anterolateral to retropharyngeal space,
anterior to the carotid space posteromedial to masticator space and medial to parotid
space.
If PPS is displaced Laterally – lesion is in
Posteriorly –
Anteriorly –
Anterolaterally –
Medially –
Pharyngeal mucosal space
Masticator space
Carotid space
Retropharyngeal space
Parotid space
It is important to differentiate a lesion arising primarily in the parapharyngeal space
from a deep lobe parotid mass, this distinction is important as a surgeon will approach
a primary parapharyngeal mass from a submandibular or oral route but a deep lobe
parotid will be approached via a transparotid approach so facial nerve control is
achieved. A lesion in the parapharyngeal space will have a thin crescent of fat along its
lateral aspect whereas a lesion arising from the deep lobe of parotid would have a fat
plane along its medial aspect.
Contents
The contents of the parapharyngeal space are fat, styloglosus, stylopharyn - geus
muscles, internal maxillary artery, inferior alveolar, lingual and auriculotemporal
nerves.
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Parapharyngeal Space
The parapharyngeal space is also a useful landmark for surgeons – as once they reach
this space, they are then aware that just posterior are important vascular structures in
the carotid space.