Suprahyoid Spaces
The spaces may be divided into three categories:
- Blind or Intrafascial spaces: formed by splitting of fascial layers
- Intercommunicating spaces: surrounding the pharynx and lying between
fascial laminae and the pharyngeal walls
- Blind "spaces": potential only, within the pharyngeal wall deep to
the buccopharyngeal fascia.
INTRAFASCIAL SPACES
Danger
Space #4 (already described)
- formed by a splitting of the prevertebral layer of
cervical fascia
- extending from the base of the skull into the thorax
The other intrafascial spaces related to the upper part of
the neck are all formed by a splitting of the superficial layer of cervical
fascia to attach to the skull, as well as to surround glands and muscles
- Potential spaces do not communicate with each other: infections within them
can spread only through rupture of their walls.
- The only one of these four spaces containing any appreciable quantity of
loose connective tissue is that associated with the muscles of mastication.
- Potential cleavage plane between the fascia and the bone.
- Limited anteriorly by superfical investing fascia and the attachment of
the anterior belly of the digastric
- Limited posteriorly by investing fascia
and the attachment of the medial pterygoid to the jaw
- Inferiorly closed by the continuity of the fascial layers
- Superiorly closed by the attachment of fascial layers to the inferior border
of the body of the mandible.
- Formed by the attachment of the superficial
layer of fascia to both the outer and inner surfaces of the body of the mandible
- attachment to the outer surface is at the lower border of the mandible
- attachment to the inner surface can be elevated from the mandible up to
the origin of the mylohyoid muscle
- Clinical: An infection here may remain localized, may discharge into
the mouth, or may spread to the masticator space.
- Anterior element of the peripharyngeal fascial spaces
(Continuous with the lateral pharyngeal space.
Infection under the tongue and the floor of the mouth can fill the submandibular
space, and pass posterior to the lateral pharyngeal space)
- Limited above by oral mucous membrane and the tongue
(lingual mucosa)
- Inferior boundary is the superficial layer of cervical
fascia (suprahyoid deep investing fascia) as it extends from the hyoid bone
to the mandible
- Posteriorly – continuous with the lateral pharyngeal
space
- Subdivided into two compartments:
- Mylohyoid muscle, stretching across the floor of the
mouth, divides the submandibular space
into a portion above this muscle: Sublingual
and a portion below: Submaxillary
- These two subdivisions can communicate by infection or
injection along the free edge of the mylohyoid muscle and about the submandibular
gland, which lies partly above and partly below the posterior portion of the
mylohyoid
- Sublingual space
- Contains the sublingual gland, the duct for the submandibular
gland, and the accessory submandibular gland, Lingual Nerve, and the hypoglossal
nerve appearing deep
- Consist of the loose connective tissue lying between
the muscles of the tongue and about the sublingual gland, the lingual and
hypoglossal nerves, and a portion of the submandibular gland and its duct.
- Paired but the two sides communicate anteriorly
- Subdivided based upon their relationships to the genioglossus
and geniohyoid muscles
- Clinical: Infection will pass down to the submandibular
space or can pass directly through the mylohyoid muscle
- Submaxillary space
is divided into subsidiary submental and submaxillary spaces by attachment
of the superficial layer of fascia to the anterior belly of the digastric
muscle,
- Corresponding to the triangle of the same name,
lies medial to the anterior belly of the digastric
- Contains Submandibular Gland with its fascial covering,
Facial Artery and Vein, Hypoglossal Nerve, Vena hypoglossi commitantes
- These spaces consist only of an easy line of cleavage
between the fascia and the muscles, unless they are abnormally distended.
- The roots of the third, second, and first molars are
all below the level of the mylohyoid. Infection of these teeth pass through
the root, directly into the submaxillary space and then to the lateral pharyngeal
space. Patient can present with problems in their airway. Never give a nerve
block if there is an infection of the submandibular space. Infection can
be passed by way of a needle tract infection to a deeper area of the body.
Submaxillary Space
- The superficial layer of fascia splits to form a capsule around the submandibular
or submaxillary gland which encloses this space
- Submandibular gland and its associated lymph nodes are embedded in and fused
with the fascial capsule.
- The outer layer of the capsule: the continuation upward of the main portion
of the superficial layer of the cervical fascia, is strong
- the inner layer is thinner and is perforated by the duct of the gland
- Clinical:
- infections arising in the region of the gland generally break inward
Masticator Space
- Formed by the splitting of the Superficial layer of cervical fascia to enclose
the ramus of the mandible, the masseter, the medial pterygoid, and the lower
portion of the temporal muscle.
- Since these structures lie between the fascial layers on the outer surface
of the masseter and the inner surface of the medial pterygoid, the loose connective
tissue and fat about them forms the potential space
- Its largest part is medial to the ramus of the mandible, between this and
the medial pterygoid, and medial and anterior to the lower portion of the
insertion of the temporal muscle.
- Posteriorly, the fascial walls of this space come together behind the ramus
of the mandible.
- Anteriorly, a part of the masseteric fascia attaches to the mandible in
front of the masseter muscle and to the insertion of the temporal muscle along
the anterior border of the ramus,
- Anteriorly, it is limited by another part passes in front of the ramus,
across the outer surface of the buccal fat pad, to attach to the maxilla and
the buccinator fascia below that
- Superiorly, it is limited deep to the temporal muscle by the origin of this
muscle from the skull,
- Superficially, it is limited by the muscle's origin from the temporal fascia.
- Deeply, anterior to the lateral pterygoid plate it extends into the pterygopalatine
fossa.
- Lies largely among the muscles of mastication. Those bordering the space
are enclosed by thin fascial layers that separate them from the fat pad and
subdivide the masticator space into compartments that do not freely communicate
with each other.
- It is traversed particularly by the mandibular nerve and the maxillary (internal
maxillary) vessels, and
- Largely filled by the buccal fat pad and its extensions posteriorly, upward,
and medially
- Clinical
- Infections of the zygomatic or temporal bones may pass to the masticator
space, and so may abscesses from the lower molar teeth
- Abscesses within this space may apparently point at the anterior aspect
of the masseter muscle, either into the cheek or the mouth, or they may point
posteriorly below the parotid gland.
Temperomasseteric Recess
- Temporalis is covered by both superficial layer of deep investing fascia
and by the masseteric fascia.
- Bounded laterally and medially by deep investing fascia
- Directly inferior it is open and communicates with the masticator space
- Clinical: Infections can pass outward to the cheek, but can also pass medial
to the medial pterygoid muscle or to the parotid gland
Space of Parotid Gland
- Encloses the parotid gland and its associated lymph nodes and the facial
nerve and great vessels traversing it.
- Attached to its surrounding fascia like the submandibular gland
- Clinical: Though the deep surface of the parotid gland is strong,
infections (usually of the glands or the nodes) may readily pass deeply and
therefore into the important lateral pharyngeal space lying deep to the parotid
gland
