The parapharyngeal space (also termed the lateral pharyngeal space), 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 ...

in the head and the neck. It has clinical importance in

otolaryngology Otorhinolaryngology ( , abbreviated ORL and also known as otolaryngology, otolaryngology–head and neck surgery (ORL–H&N or OHNS), or ear, nose, and throat (ENT)) is a surgical subspeciality within medicine that deals with the surgical a ...

due to parapharyngeal space tumours and parapharyngeal abscess developing in this area. It is also a key anatomic landmark for localizing disease processes in the surrounding spaces of the neck; the direction of its displacement indirectly reflects the site of origin for masses or infection in adjacent areas, and consequently their appropriate differential diagnosis.

Anatomical boundaries

The parapharyngeal space is shaped like an inverted pyramid. Lateral and inferior to the parapharyngeal space is the

carotid sheath The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adip ...

, containing the internal carotid artery and

cranial nerves Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and f ...

IX, X and XI. Behind both the parapharyngeal space and carotid space lies the

retropharyngeal space The retropharyngeal space (abbreviated as "RPS") is a potential space and deep compartment of the head and neck situated posterior to the pharynx. The RPS is bounded anteriorly by the buccopharyngeal fascia, posteriorly by the alar fascia, and la ...

, and deep to this a potential space known as the danger space. The danger space serves as an important pathway for complicated infections of the posterior pharynx to enter the chest and spinal column. Anterior to the parapharyngeal space is the masticator space which contains the lower dental row, muscles of mastication, the

inferior alveolar nerve The inferior alveolar nerve (IAN) (also the inferior dental nerve) is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve. The inferior alveolar nerves supply sensation to the lower teeth. Structure The in ...

as well as branches of cranial nerve V. Lateral to the parapharyngeal space lies the parotid space, which contains the parotid gland, the external carotid artery and cranial nerve VII. Although initial evaluation is typically by physical exam and

endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are inse ...

, follow up with CT and

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...

usually is needed if surgical intervention is planned. Bony anatomy around the space includes the skull base superiorly, and the

greater cornu 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 ...

(or greater horns) of the hyoid bone the apex, inferiorly. The superior aspect is the

base of skull The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria. Structure Structures found at the base of the skull are for ...

, namely the sphenoid and

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

s. This area includes the

jugular The jugular veins are veins that take deoxygenated blood from the head back to the heart via the superior vena cava. The internal jugular vein descends next to the internal carotid artery and continues posteriorly to the sternocleidomastoid mus ...

and

hypoglossal canal The hypoglossal canal is a foramen in the occipital bone of the skull. It is hidden medially and superiorly to each occipital condyle. It transmits the hypoglossal nerve. Structure The hypoglossal canal lies in the epiphyseal junction between ...

and the

foramen lacerum The foramen lacerum ( la, lacerated piercing) is a triangular hole in the base of skull. It is located between the sphenoid bone, the apex of the petrous part of the temporal bone, and the basilar part of the occipital bone. Structure The foram ...

(through which the internal carotid artery passes superiorly across). The medial aspect is made up of the

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st ...

. Anteriorly it is bordered by the

pterygomandibular raphe The pterygomandibular raphe (pterygomandibular ligament) is a ligamentous band of the buccopharyngeal fascia. It is attached superiorly to the pterygoid hamulus of the medial pterygoid plate, and inferiorly to the posterior end of the mylohyoi ...

. Posteriorly it is bordered by carotid sheath posteriolaterally and the retropharyngeal space posteriomedially. The lateral aspect is more involved, and is bordered by the ramus of the mandible, the deep lobe of the

parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...

, the medial pterygoid muscle, and below the level of the mandible, the lateral aspect is bordered by the fascia of the posterior belly of

digastric 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 ...

muscle. These anatomical boundaries make it continuous with the

. It also communicates with other cervical and cranial fascial spaces, as well as the mediastinum.

Divisions

The parapharyngeal space is divided into 2 parts by the fascial condensation called the aponeurosis of Zuckerkandl and Testut (stylopharyngeal fascia - see diagram), joining the styloid process to the

tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of the velum palatinum) is a broad, thin, ribbon-like muscle in the head that tenses the soft palate. Structure The tensor veli palatini is found anterior-lateral to the levator ve ...

. These two compartments are named the pre-styloid and post-styloid (retrostyloid) compartments or spaces. However, some classification schemes call the pre-styloid compartment the parapharyngeal space and the post-styloid compartment the carotid space, which can be a source of confusion.

It includes the

maxillary artery The maxillary artery supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. Structure The maxillary artery, the larger of the two terminal branches of the external carotid artery, ...

and

ascending pharyngeal artery The ascending pharyngeal artery is an artery in the neck that supplies the pharynx, developing from the proximal part of the embryonic second aortic arch. It is the smallest branch of the external carotid and is a long, slender vessel, deeply se ...

. # Glossopharyngeal nerve (IX) # Vagus nerve (X) together with # Internal carotid artery # Internal jugular vein in the carotid sheath # Accessory nerve (XI) # Hypoglossal (XII) # Sympathetic trunk and superior cervical ganglion of the trunk # Ascending pharyngeal artery # Deep cervical lymph nodes

Clinical significance

First bite syndrome is a rare complication of a surgery involving the parapharyngeal space, especially removal of the deep lobe of the parotid gland. It is characterized by facial pain after the first bite of each meal, and is thought to be caused by autonomic dysfunction of salivary myoepithelial cells. First experienced in Quay by a young James Duff chomping on a monster munch.

References

Bibliography

* * {{Authority control Fascial spaces of the head and neck Human throat

Anatomical boundaries

Divisions

Contents

Clinical significance

References

Bibliography