submandibular region Flashcards
submandibular region
area between the mandible and hyoid bone and 2 bellies of digastric muscle
muscles in submandibular region
hyoglossus
mylohyoid
geniohyoid
digastric
boundaries of submandibular triangle
anterior: anterior belly of digastric
posterior: posterior belly of digastric and stylohyoid
above: base of mandible
floor of submandibular triangle contains
mylohyoid
hyoglossus
middle constrictor
glands of submandibular region
submandibular and sublingual
apex of parotid
nerves of submandibular region
lingual, hypoglossal, submandibular ganglion, glossopharyngeal, nerve to mylohyoid, and marginal mandibular and cervical branches of facial nerve
arteries of submandibular region
facial and lingual arteries
vein of submandibular region
common facial vein (and internal jugular vein)
lymph nodes of submandibular region
submandibular
the deep part of the submandibular gland is between what two muscles?
hyoglossus and mylohyoid
what kind of gland is the submandibular gland?
mixed-mucous and serous
produces 70% of saliva
two parts of the submandibular gland
- superficial (larger): forms an impression on the medial aspect of the mandible (submandibular fossa)
- deep part (smaller): hooks around the posterior margin of the mylohyoid to enter the oral cavity proper. It lies on the lateral surface of the hyoglossus, lateral to the root of the tongue
submandibular duct
(Wharton’s duct)
5 cm long
-first between mylohyoid and hyoglossus then between sublingual gland and genioglossus.
-opens as 1-3 orifices on a small sublingual papilla (caruncle) at the base of the lingual frenulum bilaterally
what is the lymph drainage of the submandibular gland?
drains to submandibular lymph nodes
whats the dangerous relationship between the submandibular duct and lingual nerve?
lingual nerve hooks around duct
what is superficial to the submandibular gland?
platysma facial vein cervical and marginal mandibular branches of facial nerve submandibular lymph nodes *part of the gland is related laterally to : --mandibular fossa --facial artery --attachment of medial pterygoid
the ____ artery is embedded in the submandibular gland
facial
deep relation of the submandibular gland
mylohyoid vessels, nerve, and muscle lingual nerve and submandibular ganglion hypoglossal nerve submandibular duct hyoglossus muscle deep lingual vein
blood supply of the submandibular gland
- submental arteries which arise from the facial artery; a branch of the external carotid artery
- venous drainage through submental veins which drain into the facial vein and then the internal jugular vein
parasympathetic innervation of submandibular gland
- promotes saliva secretion
- originates from the superior salivatory nucleus through preganglionic fibers via the chorda tympani branch
- chorda tympani joins lingual nerve before synapsing at submand ganglion
- post-gang secretomotor fibers directly induce the gland to produce secretions and vasodilator fibers which accompany arteries to increase blood supply to gland
sympathetic innervation of submandibular gland
- reduces saliva secretion thru vasoconstriction
- decreases volume of salivary secretions, resulting in a more mucus and enzyme rich saliva
- originates from superior cervical ganglion, where post-ganglionic vasoconstrictor fibers travel as a plexus on the internal and external carotid arteries, facial artery and submental arteries to enter each gland
symptoms of lingual nerve injury
immediate post-op ipsilateral parathesia–permanent
-injury of chorda tympani leads to loss of taste from anterior 2/3 of tongue and loss of salivary secretion from submand and sublingual glands
symptoms of hypoglossal nerve
ipsilateral paresis or paralysis of intrinsic muscles of tongue leading to dysarthria and deviation of tongue to side of lesion
-rarely injured
symptoms of facial nerve injury
- (marginal mandibular branch)
- ipsilateral paresis or paralysis of muscles supplying lower lip and chin, including depressor labii inferioris, which presents as drooping of lower lip
- temporary–6-12 weeks
salivary duct calculi
-calculus or sialolith is a calcified deposit which can block the lumen of a duct
why is the submandibular duct the most susceptible to calculi out of all the salivary ducts? (80% of cases)
- torturous length of duct (5 cm)
- ascending secretory pathway
- nature of salivary secretion
salography
- direct injection to salivary gland to examine them
- sialogram=special type of radiograph
- calculus may be present radiographically as stricture or complete occlusion of duct
the smallest salivary gland
sublingual
deepest salivary gland
sublingual
submandibular and sublingual both contribute to only —% of overall salivary volume
3-5%
what kind of secretions does sublingual gland produce?
mixed but predominately mucous
location of sublingual
- almond shaped
- on floor of the oral cavity proper
- under tongue
- bordered laterally by mandible and medially by genioglossus muscle
- the glands form a groove on the medial surface of the mandible (sublingual fossa)
where is the sublingual gland in relation to the submandibular duct?
on medial side of sublingual
-submandibular duct and lingual nerve pass immediately next to sublingual glands between sublingual and genioglossus
both sublingual glands unite anteriorly and form a single mass thru ______ configuration around the _____
horseshoe configuration around the lingual frenulum
sublingual fold
superior aspect of the horeshoe shape
-elevated, elongated crest of mucous membrane
how do secretions from the sublingual gland flow into oral cavity?
minor sublingua ducts (Rivinus**, 8-20 ducts)
each open out onto sublingual folds
sublingual duct of Bartholin
major sublingual duct
- large accessory duct
- adheres to passing submandibular duct on its medial side
- drainage then follows the submandibular duct through the sublingual papillae
arterial supply of sublingual gland
via sublingual (from lingual artery) and submental (from facial artery)
venous drainage of sublingual gland
through sublingual (from lingual vein) and submental (from facial vein) both veins drain into internal jugular vein
nerve supply of sublingual gland
same as submandibular gland
lymphatic drainage of sublingual gland
submandibular lymph nodes
ranula
type of mucocele (mucous cyst) that occurs in the floor of the mouth inferior to the tongue
-most common disorder associated with sublingual glands due to their higher mucin content
how can ranulas form?
trauma to the delicate sublingual gland ducts causing them to rupture, with mucin then collecting within connective tissues to form a cyst
T/F Ranulas may be small and asymptomatic and can therefore be left alone
true
what is an indication for sublingual gland excision?
when a ranula causes pain and grows large enough to fill mouth causing dysphagia
cervical ranula
leaked mucin from sublingual gland or ducts that collects inferiorly beneath the mylohyoid and presents as a swelling in the neck
digastric muscle
-origin: anterior belly from digastric fossa of mandible
posterior belly from mastoid notch
-insertion: intermediate tendon attached to hyoid bone
-nerve supply: nerve to mylohyoid (V3) to anterior belly
facial nerve to posterior belly
-action: depression of mandible, elevation of hyoid bone
mylohyoid muscle
- origin: mylohyoid line of mandible
- insertion: hyoid and midline raphe with opposite side
- action: elevate hyoid, raises floor of mouth in swallowing
- innervation: nerve to mylohyoid (V3)
geniohyoid muscle
- origin: inner side of mandible (*inferior genial tubercle) above mylohyoid
- insertion: hyoid bone
- action: elevates hyoid and draws forward, depresses mandible
- innervation: C1 branch hitch-hiking with hypoglossal nerve (CN XII) **note NOT a cranial nerve
lingua nerve
- branch from posterior division of V3
- purely sensory–to anterior 2/3 of tongue
- joined by chorda tympani (branch of VII)
chorda tympani responsible for?
taste sensation of anterior 2/3 of tongue
carries parasympathetic secretomotor fibers to submandibular and sublingual salivary glands
_____ fibers relay in the _____ from which the postganglionic fibers go to the glands
parasympathetic fibers relay in the submandibular ganglion
lingual nerve travels between what two muscles and then hooks around what?
travels between mylohyoid and hyoglossus muscles and hooks around submandibular duct
-passes medial to last molar
dangerous positions for lingual nerve
- mandibular sagittal split ramus osteotomy (SSRO) causes injury 0.6% of the time
- injury during wisdom teeth removal has same risk
- likely during subperiosteal dissection along medial ramus or electrocautery
- most posteroperative paresthesias resolve without treatment
the most frequent surgical procedure to reconstruct lingual or inferior alveolar nerve injury is autogenous nerve graft reconstruction of the IAN using the _____ or _______ nerve
sural or great auricular
what nerve travels between the mylohyoid and hyoglossus muscles?
hypoglossal nerve
what nerve supplies all the muscles of the tongue except palatoglossus muscle?
hypoglossal nerve
the hypoglossal nerve is joined by what?
C1
C1 and hypoglossal nerve supply what muscles?
geniohyoid and thyrohyoid muscles
glossopharyngeal nerve supplies ?
- posterior 1/3 of tongue (general and taste sensation)
- one pharyngeal muscle (stylopharyngeus)
- parotid gland via the lesser superficial petrosal nerve
- passes deep to hypoglossus muscle
nerve to the mylohyoid supplies?
- branch of inferior alveolar
- supplies mylohyoid and anterior belly of digastric
the lingual artery arises from the ______ near the level of the hyoid bone
external carotid artery
relation of the lingual artery to the hyoglossus muscle
- posterior
- deep
- anterior to the hyoglossus
the first part of the lingual artery
lies mainly in the lesser triangle bounded by hypoglossal nerve, mylohyoid muscle, and intermediate tendon of the digastric
second part of the lingual artery
deep to the hyoglossus muscle and gives branches to the dorsum of the tongue
third part of the lingual artery
- arteria profunda linguae
- ascends between the muscles of the tongue and anastomoses with the artery of the opposite side
lingual artery supplies
tongue sublingual gland palatine tonsils palate epiglottis
suprahyoid artery supplies
suprahyoid
dorsal lingual branches of lingual artery supplies
tongue
palatine tonsils
soft palate
sublingual artery supplies
sublingual glands
floor of mouth
mandible
arteria profunda lingua (deep lingual branches) supply
the tongue
lingual side of the parasymphyseal region of the mandible is supplied by?
sublingual branch of the lingual artery, which anastomoses with the submental branch of the facial artery and incisive branches of the inferior alveolar artery
lingual vascular canals of the mandible receive branches of the _______
sublingual artery
two typical locations of the lingual vascular canal
- near the midline
2. lateral lingual canal in both premolar regions
what is the number of lingual vascular canals in each patient?
1-5
facial artery arise from?
external carotid a little above the lingual artery
where is the facial artery?
passes obliquely up deep to the digastric and stylohyoid muscles and passes in a groove on the posterior surface of the submandibular gland
where does the facial artery pass on the mandible?
anteroinferior angle of the masseter and then passes forward and upward across the cheek to the angle of the mouth then ascends along the side of the nose and ends at the medial angle of the eye (angular)
why is the facial artery torturous?
to accommodate itself to the movements of the pharynx and to the movements of the mandible, lips, cheeks
branches of facial artery in neck
tonsillar
ascending palatine
glandular
submental (TAGS)
branches of the facial artery in the face
inferior labial
superior labial
nasal
angular (ISNA)
what is the primary supply for the vascular canal?
sublingual
around which muscle is the submandibular gland wrapped?
mylohyoid
what is the significance of the innervation of the digastric muscle?
anterior: nerve to mylohyoid
posterior: facial nerve
they come from different pharyngeal arches
how are the mylohyoid muscles inserted?
midline bw mandible and hyoid bone
to which nerve is the submandibular ganglion suspended?
lingual
which muscle is immediately lateral to the middle (second) part of the lingual artery?
hyoglossus
what is the origin of the secretomotor supply of the submandibular and sublingual glands?
facial – ascending chorda tympani
where are the submandibular and sublingual ducts opening?
caruncle for submandibular
fold for sublingual
what is the clinical significance of lingual vascular canals of the mandible?
canals supplied by lingual artery (sublingual) turns into a sublingual hematoma which flips the tongue backwards and obstructs airway if you hit them during an implant placement
