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 floor ...

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 The submandibular triangle (or submaxillary or digastric triangle) corresponds to the region of the neck immediately beneath the body of the mandible. Boundaries and coverings It is bounded: * ''above'', by the lower border of the body of the man ...

, part of the

anterior triangle of the neck The anterior triangle is a region of the neck. Structure The triangle is inverted with its apex inferior to its base which is under the chin. Investing fascia covers the roof of the triangle while visceral fascia covers the floor. Anatomy Mus ...

Location and structure

Anatomic boundaries

The anatomic boundaries of each submandibular space are: * the

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" effe ...

and superficial layer of the deep cervical fascia 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 bon ...

anteriorly and laterally, * the

hyoid bone The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical verteb ...

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 The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimula ...

, which largely fills the space, * branches of the facial and lingual artery *

lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inc ...

s. * 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 d ...

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 Ancient Greek includes the forms of the Greek language used in ancient ...

s, often related to the mandibular molar teeth. This is due to the fact that the attachment of mylohyoid (the mylohyoid line) 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 perm ...

(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 ...

. 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