Fascial spaces of the head and neck

The opening of fascial spaces may be facilitated by pathogenic bacterial release of enzymes which cause tissue lysis (e.g. hyaluronidase and collagenase).

Other contents such as salivary glands, blood vessels, nerves and lymph nodes are dependent upon the location of the space.

Pus moves by the path of least resistance,[5] e.g. the fluid will more readily dissect apart loosely connected tissue planes, such the fascial spaces, than erode through bone or muscles.

In the head and neck, potential spaces are primarily defined by the complex attachment of muscles, especially mylohyoid, buccinator, masseter, medial pterygoid, superior constrictor and orbicularis oris.

One method distinguishes four anatomic groups:[3] Since the hyoid bone is the most important anatomic structure in the neck that limits the spread of infection, the spaces can be classified according to their relation to the hyoid bone:[5] In oral and maxillofacial surgery, the fascial spaces are almost always of relevance due to the spread of odontogenic infections.

Each masticator space also contains the sections of the mandibular division of the trigeminal nerve and the internal maxillary artery.

[7] Modern understanding of the fascial spaces of the head and neck developed from the landmark research of Grodinsky and Holyoke in the 1930s.

The four compartents of the right masticator space. A Temporalis muscle, B Masseter muscle, C Lateral pterygoid muscle, D Medial ptaerygoid muscle, E Superficial temporal space, F Deep temporal space, G Submasseteric space, H Pterygomandibular space, I Approximate location of infratemporal space.