1-Lateral & medial pterygoids (muscles of mastication).2-Branches of mandibular N.3-Otic ganglion.4- Chorda tympani.5-Maxillary artery.6-Pterygoid venous plexus.

Contents of infratemporal fossaContents of infratemporal fossa

Contents of infratemporal Contents of infratemporal fossa : fossa : 2-Mandibular 2-Mandibular NerveNerve Origin & course :

It is a mixed N.,formed by 2 roots : Large sensory & Small motor roots.

They unite together in foramen ovale to form the main trunk of mandibular N. (mixed).

The main trunk emerge from skull through foramen ovale to reach infratemporal fossa, then divides into a small anterior & a large posterior division.

Branches from Branches from main main trunktrunk

Meningeal branch (Nervous Spinosus) –sensory nerve : it enters skull through foramen spinosum (with middle meningeal artery) to supply meninges in middle cranial fossa.

Nerve to medial pterygoid –motor nerve : It gives off 2 branches, which pass without relay through otic ganglion to supply : tensor tympani (middle ear) & tensor vili palatini (soft palate).

Branches from Branches from Anterior Division :Anterior Division :

2 deep temporal nerves (motor) : enter deep surface of temporalis muscle to supply it.

Masseteric nerve (motor).

Nerve to lateral pterygoid muscle (motor).

Buccal nerve ( sensory) : supplies skin over cheek + mucous membrane lining cheek, (it does not supply buccinator muscle, which is supplied by buccal branch of facial nerve).

Branches from Branches from Posterior Division :Posterior Division :(mainly (mainly sensory)sensory)

1-Auriculotemporal nerve (sensory) : - It arises by 2 roots that surround middle meningeal artey, then it ascend in company with superficial temporal vessels behind TM joint. - It gives sensory branches to : skin of auricle, external auditory meatus, tympanic membrane, scalp + parotid gland, TM joint.

- It gives postganglionic para-sympathetic secretomotor fibres from otic ganglion, to supply parotid gland.

2-Lingual nerve (sensory) : - It arises from posterior division of mandibular nerve, in front of inferior alveolar N. - It lies deep to lateral pterygoid, where it is joined by chorda tympani nerve (branch of facial N. carrying taste & parasympathetic fibres). - It descends between ramus of mandible & medial pterygoid. -Then, it passes on the inner surface of the socket of lower 3rd molar tooth (dangerous area during tooth extraction) - It passes into the submandibular region superficial on the lateral surface of hyoglossus, here the sub-mandibular ganglion hangs from it. - It ends by dividing into terminal branches to the tongue to carry general & taste sensation from anterior 2/ 3 of m.m of tongue & floor of mouth. Also, it gives secretomotor para-symp. Fs.to submandibular & sublingual glands.

3- Inferior alveolar N. (mixed) : -It is the largest branch of post.division of mandibular N. - It descends on lateral surface of sphenomandibular ligament. -Then, it enters mandibular canal through mandibular foramen and runs below teeth, supplying the teeth of lower jaw. - Finally it emerges from mental foramen to supply skin of chin (sensory) -N. to mylohyoid (motor) : arises from inferior alveolar N. before it enters the mandibular foramen, it runs in mylohyoid groove of mandible. It ends by supplying mylohyoid m.+ anterior belly of digastric.

3-Otic 3-Otic GanglionGanglion It is a small parasympathetic

ganglion that is functionally associated with glosspharyngeal N.

It lies below foramen ovale, medial to mandibular N.

It receives preganglionic para-sympathetic fibres via tympanic branch , tympanic plexus & lesser petrosal N. originate from glossopharyngeal N.(relay in the ganglion).

It sends postganglionic parasympathetic secretomotor fibres via the auriculo-temporal N. to supply the parotid gland.

4-Chorda 4-Chorda TympaniTympani

It is a branch of facial N., it leaves the middle ear cavity to enter infratemporal fossa through petrotympanic fissure to join lingual N.

It carries secretomotor parasympathetic fibres to submandibular & sublingual salivary glands.

It carries also sensory taste fibres continue with lingual N. from anterior 2/3 of tongue & floor of mouth.

5-Maxillary Artery5-Maxillary ArteryIt arises behind to the neck of mandible within the substance of parotid gland, as the larger of the 2 terminal branches of external carotid artery.

It runs upward and forward, superficial to lower head of lateral pterygoid muscle, then it dips between 2 heads of lateral pterygoid to enter pterygopalatine fossa.

Branches : 1-inferior alveolar artery : follows inf.alveolar N. into mandibular canal. 2-middle meningeal artery : it passes upward between 2 roots of auriculo-temporal N. it enters skull through foramen spinosum to supply meninges. 3-deep auricular artery : to supply external auditory meatus + tympanic membrane. 4-numerous branches to muscles of mastication.

6-Pterygoid venous plexus6-Pterygoid venous plexusIt is a network of veins lying around and inside the substance of lateral pterygoid muscle.

It is drained posteriorly by maxillary v.

It communicates anteriorly with facial vein through deep facial vein.

Maxillary VeinIt drains the posterior end of pterygoid venous plexus.

It runs backward with maxillary artery on medial side of neck of mandible and joins superficial temporal vein within parotid gland to form retromandibular v.

Submandibular RegionSubmandibular Region It lies under cover of body of mandible, It lies under cover of body of mandible,

between mandible & hyoid bone.between mandible & hyoid bone. It contains the following structures :It contains the following structures : Muscles :Muscles : digastric,digastric, mylohyoidmylohyoid, , hyoglossushyoglossus, ,

geniohyoigeniohyoid, d, genioglossusgenioglossus and and styloglossusstyloglossus.. Salivary glands :Salivary glands : submandibular + sublingual. submandibular + sublingual. Nerves :Nerves : lingual, glossopharyngeal, & lingual, glossopharyngeal, &

hypoglossal.hypoglossal. Parasympathetic ganglion :Parasympathetic ganglion : submandibular. submandibular. Blood vessels :Blood vessels : facial & lingual. facial & lingual. Lymph nodes :Lymph nodes : submandibular. submandibular.

Muscles of Muscles of submandibular region :submandibular region :1-digastric muscle :

Origin : by 2 bellies -anterior belly : from digastric fossa on the lower border of body of mandible close to symphysis menti. -posterior belly : from medial surface of mastoid process.

Insertion : into the intermediate tendon which is cnnected to hyoid bone by a fibrous loop of deep fascia. This intermediate tendon pierces stylohoid insertion.

Nerve supply : anterior belly : by N.to mylohyoid from mandibular. Posterior belly : by facial N.

Action : depress mandible or elevate hyoid bone during swallowing.

2-mylohyoid muscle :

Origin : flate triangular sheet of muscle arise from mylohyoid line of mandible.

Insertion : the anterior fibres into a median fibrous raphe, the mylohyoid raphe which extends in the median plane from symphysis menti to hyoid bone. The posterior fibres into body of hypoid bone.

Nerve supply : mylohyoid N. from inferior alveolar N.

Action : -they supports tongue & floor of mouth. -they elevate floor of mouth & hyoid bone during 1st stage of swallowing. -they depress mandible (open mouth) when hyoid bone is fixed.

3-hyoglossus muscle :Origin :upper border of body and greater cornu of hyoid bone.

Insertion : it lies deep to mylohyoid to be inserted to side of posterior ½ of tongue.

Nerve supply : hypoglossal N.

Action :depresses the tongue.

4-styloglossus muscle :

Origin : styloid process.

Insertion : it passes downward on lateral surface of superior constrictor muscle to insert into side of tongue decussating with hyoglossus m.

Nerve supply : hypoglossal N.

Action : retracts the tongue backward.

5-Geniohyoid muscle :Origin : inferior mental spine, behind symphysis menti of mandible.

Insertion : into anterior surface of body of hyoid bone.

Nerve supply : 1st cervical N. via hypoglossal N.

Action : elevate hyoid bone or depress mandible if hyoid bone is fixed.

6-Genioglossus muscle : it is a fan-shaped m.lies medial to hyoglossus m.

Origin : superior mental spine, behind symphysis menti of mandible.

Insertion : into whole length of tongue + superior fs.into tip of tongue + few inferior fs. Into body of hyoid bone.

Nerve supply : hypoglossal N.

Action : 1-single m. : pulls tongue to opposite side. 2-The 2 ms. Protrude the tongue forward.