The submandibular space is a
fascial space of the head and neck (sometimes also termed fascial spaces or tissue spaces). It is a
potential space
In anatomy, a potential space is a space between two adjacent structures that are normally pressed together (directly apposed). Many anatomic spaces are potential spaces, which means that they are potential rather than realized (with their realiz ...
, and is paired on either side, located on the superficial surface of the
mylohyoid muscle
The mylohyoid muscle or diaphragma oris is a paired muscle of the neck. It runs from the mandible to the hyoid bone, forming the floor of the oral cavity of the mouth. It is named after its two attachments near the molar teeth. It forms the fl ...
between the anterior and posterior bellies of the
digastric muscle
The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle belli ...
.
The space corresponds to the anatomic region termed the
submandibular triangle, part of the
anterior triangle of the neck.
Location and structure
Anatomic boundaries
The anatomic boundaries of each submandibular space are:
* the
mylohyoid muscle
The mylohyoid muscle or diaphragma oris is a paired muscle of the neck. It runs from the mandible to the hyoid bone, forming the floor of the oral cavity of the mouth. It is named after its two attachments near the molar teeth. It forms the fl ...
superiorly,
* the skin, superficial fascia,
platysma muscle
The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effect ...
and superficial layer of the
deep cervical fascia
The deep cervical fascia (or fascia colli in older texts) lies under cover of the platysma, and invests the muscles of the neck; it also forms sheaths for the carotid vessels, and for the structures situated in front of the vertebral column. Its a ...
inferiorly and laterally,
* the medial surface of the
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
anteriorly and laterally,
* the
hyoid bone posteriorly,
* the anterior belly of the digastric muscle medially.
Communications
The communications of the submandibular space are:
* medially and anteriorly to the
submental space (located medial to the paired submandibular spaces, separated from them by the anterior bellies of the digastric muscles).
* posteriorly and superiorly to the
sublingual space (located above the mylohyoid muscle)
* inferiorly to the
lateral pharyngeal space
Contains
In health, the contents of the space are:
* the
submandibular gland, which largely fills the space,
* branches of the
facial and lingual artery
*
lymph nodes.
* cranial nerve XII
* nerve to mylohyoid muscle
Clinical relevance
Infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...
s may spread into the submandibular space, e.g.
odontogenic infection
An odontogenic infection is an infection that originates within a tooth or in the closely surrounding tissues. The term is derived from '' odonto-'' (Ancient Greek: , – 'tooth') and '' -genic'' (Ancient Greek: , ; – 'birth'). The most common ...
s, often related to the
mandibular molar teeth. This is due to the fact that the attachment of mylohyoid (the
mylohyoid line
The mylohyoid line is a bony ridge on the internal surface of the mandible. It runs posterosuperiorly. It is the site of origin of the mylohyoid muscle, the superior pharyngeal constrictor muscle, and the pterygomandibular raphe.
Structure
The ...
) becomes more superior towards the posterior of the mandible, meaning that the roots of the posterior teeth are more likely to be below mylohyoid than above.
Signs and symptoms of a submandibular space infection might include
trismus
Trismus, commonly called ''lockjaw'' as associated with tetanus, is a condition of limited jaw mobility. It may be caused by spasm of the muscles of mastication or a variety of other causes. Temporary trismus occurs much more frequently than perma ...
(difficulty opening the mouth), inability to
palpate
Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...
(feel) the inferior border of the mandible and swelling of the face over the submandibular region.
If the space contains pus, the usual treatment is by
incision and drainage
Incision and drainage (I&D), also known as clinical lancing, are minor surgical procedures to release pus or pressure built up under the skin, such as from an abscess, boil, or infected paranasal sinus. It is performed by treating the area with a ...
. The site of the incision is extra-oral, and usually made 2–3 cm below, and parallel to, the inferior border of the mandible.
Ludwig's angina
Ludwig's angina (lat.: Angina ludovici) is a type of severe cellulitis involving the floor of the mouth and is often caused by bacterial sources. Early in the infection, floor of the mouth raises due to swelling, leading to difficulty swallowing s ...
is a serious infection involving the submandibular, sublingual and submental spaces bilaterally.
Ludwig's angina may extend into the pharyngeal and cervical spaces, and the swelling can compress the airway and cause
dyspnoea
Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing dis ...
(difficulty breathing).
References
{{mouth anatomy
Fascial spaces of the head and neck
Otorhinolaryngology
Oral and maxillofacial surgery
Mouth