Retromandibular Area
The retromandibular area is the inferior continuation of the infratemporal fossa. The retromandibular area is also referred to as the parapharyngeal space. Large blood vessels including the internal and external carotid arteries pass through the retromand
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The retromandibular area (Fig. 13.1) as described here is rarely addressed in textbooks. It is a diffuse region located behind the inferior portion of the mandibular ramus, but lacking specific boundaries except the posterior margin of the ramus. Superiorly, the retromandibular area is continuous with the infratemporal space (Chap. 11), medially it extends to the retropharyngeal space, and inferiorly it connects to the lateral cervical space. Superficially, the retromandibular area is covered by the skin of the neck, external fat layer, superficial
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fascia, platysma, and superficial cervical fascia (Candirli et al. 2014). Typical anatomical structures of the retromandibular area include the lower portion of the parotid glands (Chap. 4); the muscles originating from the styloid process; the glossopharyngeal nerve (CN IX), hypoglossal nerve (CN XII), and vagus nerve (CN X); and the external and internal carotid arteries (Chaps. 4 and 23). The muscles and ligaments originating from the styloid process have a common function in lifting the aerodigestive elements upward and backward.
masseter
MA STA
FA FA ECA
Fig. 13.1 Dissection of the right side of a cadaveric head showing the retromandibular area (dotted white line) with the parotid gland and the ramus removed. DgMab anterior belly of digastric muscle, DgMpb posterior belly of digastric muscle, ECA external carotid artery, FA facial artery, MA maxillary artery, SHM stylohyoid muscle, STA superficial temporal artery
lower mandibular border submandibular gland FA
DgMpb
DgMab SHM
© Springer International Publishing Switzerland 2017 T. von Arx, S. Lozanoff, Clinical Oral Anatomy, DOI 10.1007/978-3-319-41993-0_13
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Styloid Process The styloid process (g, stylos = pillar) is a spiny process located at the bottom of the temporal bone just anteromedial to the stylomastoid foramen and lateral to the jugular foramen and carotid canal (Okur et al. 2014) (Figs. 13.2, and 13.3). In fact, the styloid process is the most inferior structure of the temporal bone. The styloid process points inferoanteriorly and it is slightly angulated medially. The mean length of the styloid process ranges between 20 and 30 mm, but is considered elongated when it exceeds 30 mm (Figs. 13.4 and 13.5) (Balcioglu et al. 2009). Calcification of the stylohyoid ligament may also result in elongation (Öztunc et al. 2014). The tip of the process is located lateral to the pharyngeal wall immediately behind the tonsillar fossa. Usually, the styloid process lies between the external and internal carotid arteries (Balcioglu et al. 2009). Three thin muscles and two ligaments originate from the styloid process (see below). Together with the posterior belly of the digastric muscle, the styloid muscles and ligaments form the styloid diaphragm that is considered a key landmark in the retromandibular area. The styloid diaphragm divides the retromandibular-pharyngeal space into pre- and retrostyloid regions (Prades et al. 2014). The external carotid artery passes through the styloid diaphragm;
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