Sub-masseteric infections occupy the potential space between the lateral border of
the mandible and the masseter muscle. This is not a fascial-lined space; infection
in this area is in direct contact with the masseter muscle and usually induces
intense spasm in the muscle, resulting in a profound limitation in mouth opening
(trismus).
Internal pterygoid space infections occupy the fascia-lined space between the
internal pterygoid muscle and the medial aspect of the mandible. Infections in this
area cause a less profound trismus but can result in airway embarrassment. They
can also result from Inferior Alveolar Nerve block.
The sub-mandibular space consists of a splitting of the investing fascia of the neck
to enclose the submandibular salivary gland and is in continuity with the internal
pterygoid and para-pharyngeal spaces. Infections in this region can cause airway
embarrassment and, when bilateral with associated cellulitis, is termed Ludwigs
Angina. This is very serious and potentially life-threatening.
Infections occur between the pharyngeal mucosa and superior constrictor muscle.
Infections in this region are also potentially life-threatening and require urgent
attention.
