Infratemporal fossa

邱瑞珍 rueijen@tmu.edu.tw
解剖學暨細胞生物學科 # 3261
Infratemporal fossa
Wedge-shaped
Inferior to temporal fossa
Between ramus of mandible and
wall of pharynx
• Roof
Inferior surface of greater wing of sphenoid and temporal bone
Contain: foramen spinosum, foramen ovale, petrotympanic fissure,
lateral to infratemporal crest of greater wing of sphenoid
Open superiorly to temporal fossa
• Lateral wall
Medial surface of ramus of mandible
Contain: opening to mandibular canal
• Medial wall
Anteriorly: lateral plate of pterygoid process
Posteriorly: pharynx and 2 muscles
tensor and levator veli palatine muscles
Contain: pterygomaxillary fissure
allow structures to pass between infratemporal fossa and
pterygopalatine fossa
• Anterior wall
Posterior surface of maxilla
Contain: alveolar foramen
upper part open as inferior orbital fissure
Contents
Major contents:
sphenomandibular ligament,
medial and lateral pterygoid muscles,
maxillary artery,
mandibular nerve[V3],
branches of facial nerve[VII],
glossopharyngeal nerve[IX],
pterygoid plexus of veins
Sphenomandibular ligament
Extracapsular ligament of temporomandibular ligament
Attach superiorly: spine of sphenoid bone
Inferiorly: ligula of mandible and
posterior margin of mandibular foramen
Medial pterygoid
Quadrangular in shape
• Deep head
Attach above medial surface of lateral plate of pterygoid process
and associated surface of pyramidal process of palatine bone
Descend obliquely downward
Medial to sphenomandibular ligament
Attach to roughened medial surface of ramus of mandible
near angle of mandible
• Superficial head
Originate from tuberosity of maxilla and
adjacent pyramidal process of palatine bone
Join with deep head to insert on mandible
Medial pterygoid action :
mainly elevate mandible
(pass obliquely backward to insert into mandible)
also assist lateral pterygoid muscle
in protruding lower jaw
innervated by nerve to medial pterygoid from V3
Lateral pterygoid
a thick triangular muscle
• Upper head
Originate from roof of infratemporal fossa
inferior surface of greater wing and
infratemporal crest
lateral to foramen ovale and spinosum
• Lower head
Larger than upper head
Originate from lateral surface of lateral plate of
pterygoid process
Inferior part insinuate between 2 heads of medial pterygoid
Fibers from both heads of lateral pterygoid:
converge to insert into pterygoid fovea of neck
of mandible and
into capsule of temporomandibular joint
in the region: capsule attached internally to articular disc
Fiber of lateral pterygoid muscle:
almost horizontally
Contract:
pull articular disc and head of mandible
forward onto articular tubercle
major protrude of lower jaw
Innervated by:
nerve to lateral pterygoid from V3
When lateral and medial pterygoid contract on only one side:
chin move to opposite side
When opposite movement at 2 TMJ coordinated:
chewing movement results
Mandibular nerve [V3]
Largest of 3 divisions of trigeminal nerve [V]
V1 and V2: pure sensory
V3: mixed, both sensory and motor
General sensation: teeth and gingivae of mandible,
anterior 2/3 of tongue, mucosa on floor of oral cavity,
lower lip, skin over temple and lower face, part of cranial
dura mater
Motor innervation:
most muscle that move mandible, tensor tympani (middle ear),
tensor veli palatine (soft palate)
All branches of V3: originate in infratemporal fossa
Sensory part: from trigeminal ganglion
• Sensory part
Drop vertically through foramen ovale
Enter infratemporal fossa
Between tensor veli palatine muscle and lateral pterygoid muscle
• Motor root
Small
Pass medial to trigeminal ganglion
Then pass through foramen ovale
Immediately join sensory part
Branches
After sensory and motor join:
small meningeal branch
nerve to medial pterygoid
anterior trunk
posterior trunk
• Anterior trunk
buccal (predominantly sensory),
masseteric, deep temporal nerves, nerve to lateral pterygoid (motor)
• Posterior trunk
auriculotemporal, lingual, inferior alveolar nerves (sensory)
nerve to mylohyoid (motor)
Meningeal branch
From medial side of V3
Ascends to leave infratemporal fossa
with middle meningeal artery
reenter cranial cavity through foramen spinosum
Sensory for dura mater
mainly of middle cranial fossa
Also supply mastoid cells
communicate with middle ear
Nerve to medial pterygoid
Originate medially from V3
Descend to enter and supply deep surface of muscle
Near origin: 2 small branches
• One supply tensor veli palatine
The other: ascend to supply tensor tympani muscle
Buccal nerve
Branch of anterior trunk of V3
Predominantly sensory:
but may also carry motor innervation
to lateral pterygoid muscle and
temporalis muscle
Pass laterally between upper and lower heads of lateral pterygoid
Descend around anterior margin of insertion of temporalis
Continue into cheek lateral to buccinators
Supply general sensory nerve to:
skin, oral mucosa, buccal gingivae of lower molars
Masseteric neve
A branch of anterior trunk of V3
Pass laterally over lateral pterygoid
Through mandibular notch to penetrate
and supply muscle
Deep temporal nerves
Usually 2
From anterior trunk of V3
Pass laterally above lateral pterygoid
Curve around infratemporal crest
Supply temporalis from deep surface
Nerve to lateral pterygoid
Originate directly as a branch from anterior trunk of V3
or from buccal branch
Pass directly into deep surface of muscle
Auriculotemporal nerve
First branch of posterior trunk of V3
Originate as 2 roots
Pass posteriorly around middle meningeal artery
First between tensor veli palatini
and upper head of lateral pterygoid
Then between sphenomandibular ligament
and neck of mandible
Curve laterally around neck of mandible
Ascend deep to parotid gland between joint and
ear
Terminal branch of auriculotemporal nerve:
carry general sensation from skin
over a large area of temple
also external ear, external auditory meatus,
tympanic membrane, TMJ
Also deliver postganglionic parasympathetic nerves
from glossopharyngeal nerve to parotid gland
Lingual nerve
A major sensory branch of posterior trunk
Carry general sensation from:
anterior 2/3 tongue, oral mucosa on floor of oral cavity,
lingual gingivae associated with lower teeth
Joined high by chorda tympani branch of facial nerve
Chorda tympani carry:
• Taste from anterior2/3 of tongue
• Parasympathetic fiber to all salivary glands
below the level of oral fissure
Lingual nerve:
descend between tensor veli palatini and lateral pterygoid muscle
joined by chorda tympani
then descend across lateral surface of medial pterygoid muscle
to oral cavity
enter oral cavity between posterior attachment
of mylohyoid muscle and pterygomandibular
raphe
As lingual nerve enter floor of oral cavity:
in a shallow groove on medial surface of mandible
immediately inferior to last molar tooth
here, palpable through oral mucosa
in danger when operating on molar teeth and gingivae
Lingual nerve:
pass into tongue on lateral surface of hyoglossus m.
submandibular ganglion:
preganglionic parasympathetic fiber
 postganglionic fiber
Inferior alveolar nerve
A major sensory branch of posterior trunk
Innervating all lower teeth and associated gingivae
Also supply mucosa and skin of lower lip and skin of chin
One motor branch:
innervate mylohyoid muscle and
anterior belly of digastric muscle
Inferior alveolar nerve:
originate deep to lateral pterygoid from posterior trunk
associated with lingual nerve
descend on lateral surface of medial pterygoid muscle
pass between sphenomandibular ligament and mandible
then enter mandibular canal through mandibular foramen
give origin to nerve to mylohyoid:
lie in mylohyoid groove inferior to foramen
continue anteriorly below floor of oral cavity
innervate mylohyoid muscle and
anterior belly of digastric muscle
Inferior alveolar nerve:
supply branches to 3 molar teeth and second premolar tooth
and associated labial gingivae
divide into 2 terminal branches
• Incisive nerve
In mandibular canal
Supply 1st premolar, incisor, canine teeth
and related gingivae
• Mental nerve
Exits mandible through mental foramen
Supply lower lip and chin
Chorda tympani and lesser petrosal nerve
Branches of 2 cranial nerve join branches of V3 in infratemporal fossa
• Chorda tympani - branch of facial nerve
• Lesser petrosal nerve – origin from a branch of glossopharyngeal nerve
Chorda tympani
Carry taste from anterior 2/3 of tongue and
parasympathetic innervation to salivary glands
Origin from facial nerve within temporal bone
association with mastoid wall of middle ear
Pass anteriorly enter lateral aspect of middle ear
Separate from tympanic membrane by
handle of malleus
Leave middle ear through medial end of
petrotympanic fissure
Enter infratemporal fossa
Descend medial to spine of sphenoid
then lateral pterygoid
Join lingual nerve
Preganglionic parasympathetic fiber carry in chorda tympani:
synapse with post fiber in submandibular ganglion
hangs off the lingual nerve in floor of oral cavity
Postganglionic parasympathetic fiber:
leave submandibular ganglion
• Reenter lingual nerve to target
• Pass directly from submandibular ganglion into gland
Lesser petrosal nerve
Carry mainly parasympathetic fiber destined for parotid gland
Preganglionic fiber : locate in glossopharyngeal nerve
exit jugular foramen  tympanic nerve
Tympanic nerve reenter temporal bone
Participate in formation of tympanic plexus
lesser petrosal nerve: a branch of tympanic plexus
Lesser petrosal nerve:
contain mainly preganglionic parasympathetic fibers
leave middle ear and enter middle cranial fossa
pass medially and descend through foramen ovale
with mandibular nerve
In infratemporal fossa:
preganglionic fiber synapse with cell bodies of post fibers
in otic ganglion
Postganglionic parasympathetic fibers:
leave ganglion and join
auriculotemporal nerve
to parotid gland
Maxillary artery
Largest branch of external carotid artery
A major source of blood supply for:
nasal cavity, lateral wall and roof of oral cavity,
all teeth, dura mater
Pass through and supply infratemporal fossa
Then enter pterygopalatine fossa
Originate within parotid gland
Then pass forward: between neck of mandible and
sphenomandibular ligament
into infratemporal fossa
Ascend obliquely through infratemporal fossa to
enter pterygopalatine fossa
Branches
• First part
Between neck of mandible and sphenomandibular ligament
2 major branches :
middle meningeal artery and
inferior alveolar artery
A number of smaller branes:
deep auricular, anterior tympanic,
accessory meningeal
• Second part
Related to lateral pterygoid muscle
Give origin to:
deep temporal, masseteric, buccal,
pterygoid branches
• Third part
In pterygopalatine fossa
Middle meningeal artery
Ascend vertically
Pass through foramen spinosum
Enter cranial cavity
Pass superiorly between sphenomandibular
ligament and lateral pterygoid muscle
Pass between 2 roots of auriculotemporal n.
Largest of meningeal vessels
Supply much of dura mater, bone,
related bone marrow
Inferior alveolar artery
Descend from maxillary artery
Enter mandibular foramen and canal with nerve
Supply all lower teeth
Also buccal gingivae, chin, lower lip
Before enter mandible:
give rise mylohyoid branch
accompany nerve to mylohyoid
Deep auricular, anterior tympanic, accessory meningeal arteries
Small branches
Supply :
external acoustic meatus, deep surface of tympanic membrane,
cranial dura mater
Accessory meningeal branch:
also contribute small branch to muscles in fossa
Branches from second part
Deep temporal artery: usually 2
originate from 2nd part
with nerves supply temporalis
Pterygoid arteries:
supply pterygoid muscles
Masseteric artery:
with nerve through notch
supply masseter
Buccal artery:
with buccal nerve
supply skin, muscle, oral mucosa of cheek
Pterygoid plexus
A net work of veins
Between medial and lateral pterygoid muscles
And between lateral pterygoid and
temporalis muscles
Veins drain region supply by arteries:
connect with pterygoid plexus
Veins include:
nasal cavity, roof, lateral wall of oral cavity,
all teeth, muscles in fossa, paranasal sinuses,
nasopharynx
Inferior ophthalmic vine:
from orbit drain through inferior orbital fissure into plexus
Pterygoid plexus connect:
• Posteriorly
via a short maxillary vine
with retromandibular vein
• Anteriorly
via deep facial vein
with facial vein
Temporomandibular joints
Allow opening and closing of mouth
and complex chewing or side-to-side movements
Synovial joint
Formed between head of mandible and fossa and tubercle
Covered by fibrocartilage
Completely divided by a fibrous articular disc
• Lower part
allow mainly hinge-like depression and
elevation of mandible
• Upper part
allow head of mandible to translocate
forward and backward
Opening mouth:
involve both depression and protrusion
Forward or protrusive movement:
allow greater depression of mandible
by preventing backward movement of
angle of mandible into structures
in neck
Joint capsule
Synovial membrane: line all nonarticular surfaces
upper and lower compartment
attached to margins of articular disc
Fibrous membrane of joint capsule:
enclose TMJ complex and attached
• Above along anterior margin of articular tubercle
• Laterally and medially along margins of articular fossa
• Posteriorly to region of tympanosquamous suture
• Below around upper part of neck of mandible
Disc attach around its periphery to inner aspect of fibrous membrane
Extracapsular ligaments
3 extracapsular ligaments with TMJ
• Lateral ligament
closet to joint
lateral to capsule
run diagonally backward from margin of
articular tubercle to neck of mandible
• Sphenomandibular ligament
medial to joint
from spine of sphenoid bone
to lingual on medial side of mandible
• Stylomandibular ligament
pass from styloid process
to posterior margin of mandible
步驟
Infratemporal Fossa
1. 在頭骨上複習 infratemporal fossa 的範圍
2. 在 temporalis 肌肉 tendon 後方，從 mandibular notch 處
伸入鑷子， 往前延伸到臼齒的位置，
分開骨頭與深層組織
3. 依照圖的指示，在 mandible 上標示切線，沿著 1
的標示，將 coronoid process 鋸下，
小心深層的結構
4. 用骨剪小心剪下其他骨頭。

Cut 1
5. 將 coronoid process 連同 temporalis muscle 往上翻
6. 將 temporalis muscle 從 skull 上剝除下部，注意
deep temporal nerves and arteries 會進入肌肉的深層。
nerves 為 CN V3 的分支，為 temporalis muscle 提供 motor
innervation 。
7. 在 neck 的地方伸入一隻鑷子，分開骨頭與深層組織
8. 將 neck 鋸開 (cut 2) 。
9. 在 mandible 的深層，找出 inferior alveolar nerve and vessels 。
10. 用骨剪慢慢將 mandible 移除，從 notch 往下，直到 lingual (cut 3) 。
11. 將剩餘的骨頭移除。
12. 清楚 inferior alveolar nerve and vessels ，觀察其進入 mandibular
foramen
13. 找出 nerve to mylohyoid ，會在 inferior alveolar nerve 後方，
在 inferior alveolar nerve 進入 foramen 的地方分出
14. Inferior alveolar nerve and vessels
會進入 mandibular foramen 並往前分布在 mandibular canal 中，
此神經提供下排牙齒的 sensory innervation 。
15. 複習 mental nerve ，是 inferior alveolar nerve 的分支，穿過 mental
foramen ，支配下巴與下唇。
16. 在 ramus 的內側，找出 lingual nerve ，位於 inferior alveolar nerve
的前方，但是沒有進入 foramen ，通過第三臼齒的內側，
提供舌頭前 2/3 與口腔底部的 sensory innervation 。
Maxillary Artery
1. 從 external carotid artery 分支的地方，找出
maxillary artery 。此血管分出之後，水平分布
穿過 infratemporal fossa ，經過 lateral
pterygoid muscle 的淺層 (2/3 of cases)
或深層 (1/3 of cases) 。
2. 找出 maxillary artery 的分支
3. 在靠近 maxillary artery 從 external carotid
artery 分出的附近，找出 middle meningeal
artery 。從 neck of mandible 的內側發出，
往上走，穿過 lateral pterygoid muscle 的
深層。在顱骨的下方，血管會被
auriculotemporal nerve 環繞。之後經由
foramen spinosum 進入
middle cranial fossa ，
供應血液到 dura mater 。
4. 找出 deep temporal arteries (anterior, posterior)
從 maxillary artery 上方發出，往上走並通過
infratemporal fossa 的外側，進入 termporalis
muscle 的深層。
5. 找出 masseteric artery ( 已切斷 ) 。
從 maxillary artery 分出之後會往外側分布，
通過 mandibular notch ，進入 masseter muscle
的深層。
6. 找出 inferior alveolar artery ，並追蹤
其進入 mandibular foramen ，伴隨著
inferior alveolar nerve 。
7. 找出 buccal artery ，往前走向分布在 buccinator
的表面，並供應血液到臉頰。 ( 可能很小 )
Pterygoid muscles
1. 在 infratemporal fossa 找出 lateral pterygoid
muscle ，水平分布。
2. 清出肌肉的範圍，並分出 2 各 heads 的界線，
此肌肉受到 CN V3 的分支的支配。
3. 複習肌肉的接點與作用。
4. 在 lateral pterygoid muscle
的下方為 medial
pterygoid muscle 。
將 masseter 復位，
觀察 fiber 走向，
2 者很類似。
5. 觀察 lingual nerve 與 inferior alveolar nerve
會從 lateral 與 medial 之間穿出。
6. 清出 medial pterygoid muscle ，可以利用 lingual
nerve 作為標記，分開 medial 與 lateral
pterygoid muscle 。
7. 複習 medial pterygoid muscle 的接點與作用。
8. 找出 lateral pterygoid
的下緣。
9. 用剪刀將 lateral 從靠近
後方的接點，剪開
肌肉。
10. 一小部分一小部分的移除肌肉，保留淺層的
血管的神經。
11. 沿著 lingual nerve 與 inferior alveolar nerve
往上追蹤，一直到顱底的 foramen ovale 。
12. 找出 chorda tympani ，
在 lingual nerve 後方
13. 清出 maxillary artery ，直到進入
pterygopalatine fossa 。
14. 在進入 pterygopalatine fossa 之前， maxillary
artery 分出 4 條分支 : posterior superior
alveolar artery, infraorbital artery,
descending palatine artery, sphenopalatine
artery 。
Temporomandibular Joint
1. 找出 temporomandibular joint (TMJ) 的 capsule ，
用 2 支鑷子去夾，會發現 capsule 有點鬆，
活動性比較大。利用圖譜查看 capsule 的外側面，
有 lateral ligament 強化。
2. 保留淺層的血管與神經，
將其拉到邊邊。
3. 用刀子將 capsule 與 lateral
ligament 清開。
4. 在 joint 裡面，觀察 articular disc 會在 fossa
與 head of mandible 之間。 Lateral
pterygoid muscle 的 tendon 會同時接在 neck
of mandible 與 articular disc 。
5. 觀察 disc ，中間比較薄，旁邊比較厚。
6. 將探針伸入關節，有 2 個 cavities ，
上方為 superior synovial
cavity ，下方為 inferior
synovial cavity 。
7. 移動剩餘的 head of mandible ，觀察與 TMJ 相關
的動作。 Protrusion and retrusion 時，
在 superior 觀察 articular disc 與 mandibular
fossa 會有 gliding movement ；在 inferior 觀察
disc 與 head of mandible 會出現 hinge
movement 。
8. 將你自己的小指伸入耳朵，動一動下巴 : elevate,
depress, protrude, retrude ，感覺一下
head of mandible 。
Lists :
Muscles:
Masseter muscle, Temporalis muscle,
lateral and medial pterygoid m.,
Nerves and vessels:
Deep temporal arteries and nerves,
Inferior alveolar nerve and vessels,
Nerve to mylohyoid, Lingual nerve,
Maxillary artery, middle meningeal artery,
deep temporal arteries, masseteric artery,
buccal artery, chorda tympani,
(posterior superior alveolar a.,
infraorbital artery, descending palatine a.,
Sphenopalatine a.)