Pterygopalatine Region-2 PDF

Parotid, Temporal, and Pterygopalatine Regions Oratai Weeranantanapan, PhD, FHEA School of Preclinical Sciences, Institute of Science, Suranaree University of Technology 601321 Respiratory System, 25th June 2024...

Parotid, Temporal, and Pterygopalatine Regions Oratai Weeranantanapan, PhD, FHEA School of Preclinical Sciences, Institute of Science, Suranaree University of Technology 601321 Respiratory System, 25th June 2024 1  OUTLINE I. Parotid region o Parotid gland o Structures within the parotid gland o Innervation of the parotid gland and related structures o Clinical correlations II. Temporal region o Temporal fossa o Infratemporal fossa o Temporomandibular joint (TMJ) o Muscles of mastication o Neurovasculature of infratemporal fossa o Clinical correlations III. Pterygopalatine region and Its contents 2  Parotid Region o Posterolateral part of the facial region, bounded by the: o Superior: Zygomatic arch o Posterior: External ear and anterior border of the sternocleidomastoid o Medial: Ramus of Mandible o Inferior: Angle and inferior border of the mandible o Parotid region includes the 1. Parotid gland and duct 2. Parotid plexus of facial nerve (CN VII) 3. Retromandibular vein 4. External carotid artery 5. Masseter muscle 3  Parotid Gland o The largest of three paired salivary glands o It is enclosed within a tough fascial capsule, the parotid sheath (capsule) o An Irregular shape o Apex: Posterior to the angle of the mandible o Base: Zygomatic arch o Parotid duct passes horizontally from anterior edge of the gland and enters oral cavity though a small orifice opposite the 2nd maxillary molar tooth 4  Structures within Parotid Gland oContents embedded within parotid gland (from superficial to deep) 1. Parotid plexus of the facial nerve (CN VII) and its branches. 2. Retromandibular vein 3. External carotid artery 4. On the parotid sheath and within the gland are parotid lymph Facial nerve passes and leaves the skull through stylomastoid foramen, enters parotid gland, and branches to temporal, zygomatic, buccal, mandibular, and nodes cervical branches. 5  Innervation of Parotid Region and Related Structures o Sensory nerve fibres: Great auricular nerve (a branch of the cervical plexus) and auriculotemporal nerve (a branch of CN V3) o Parasympathetic component of the glossopharyngeal nerve (CN IX) supplies presynaptic secretory fibres to the otic ganglion. The postsynaptic parasympathetic fibres are conveyed from the ganglion to the parotid gland by the auriculotemporal nerve. Stimulation of the parasym-pathetic fibres produces a thin, watery saliva. o Sympathetic fibres are derived from the cervical ganglia through the external carotid nerve plexus on the external carotid artery. 6  Clinical Correlations: Mumps o Mumps or epidemic parotitis o A highly contagious viral illness o It affects the inside mucosa of the mouth and the parotid glands o Symptoms: Fever, Headache, Muscle pain, Pain when eating, Pain in the ears, jaw, chin, Swollen cheeks, jaw o How it spreads: Airborne, Saliva, Touching contaminated surface 7  OUTLINE I. Parotid region o Parotid gland o Structures within the parotid gland o Innervation of the parotid gland and related structures o Clinical correlations II. Temporal region o Temporal fossa o Infratemporal fossa o Temporomandibular joint (TMJ) o Muscles of mastication o Neurovasculature of infratemporal fossa o Clinical correlations III. Pterygopalatine region and Its contents 8  Temporal Region o Temporal region of the head includes the lateral area of the scalp and the deeper soft tissues overlying the temporal fossa of the cranium, superior to zygomatic arch o Temporal region consists of 1. Temporal fossa- superior to the zygomatic arch 2. infratemporal fossa—inferior to the zygomatic arch 9  Temporal Region 1. Temporal fossa boundaries: o Superior and posterior: Temporal lines o Anterior: Frontal and zygomatic bones o Lateral: Zygomatic arch o Inferior: Infratemporal crest o Floor: Pterion (Frontal, temporal parietal and greater wing of sphenoid bones) o Roof: Temporal fascia The fan-shaped temporalis muscle arises from the bony floor and overlying temporal fascia 10 Temporal Fossa 11  Temporal Fossa o Contents 1. Temporalis muscle 2. Zygomaticotempo-ral branches of the maxillary nerve (CN V2), which enters the region through foramina on the temporal fossa surface of the zygomatic bone 12 Infratemporal Fossa 13 Infratemporal Fossa: Bone Review 14  Infratemporal Fossa 2. Infratemporal fossa boundaries: o Lateral: Ramus of mandible o Medial: Lateral pterygoid plate o Anterior: Posterior aspect of maxilla o Posterior: Tympanic plate and mastoid and styloid processes of temporal bone o Superior/roof: Inferior surface of greater wing of sphenoid o Inferior: where the medial pterygoid muscle attaches to the mandible near its angle. 15  Infratemporal Fossa o Contents 1. Inferior part of temporalis muscle 2. Medial and lateral pterygoid muscles 3. Maxillary artery 4. Pterygoid venous plexus 5. Mandibular nerve and its branches (Inferior alveolar, lingual and buccal nerves, chorda tympani) 6. Otic ganglion Note: Chorda tympani is a branch of the facial nerve (CN VII) joins branch of the mandibular nerve (CN V3) 16  OUTLINE I. Parotid region o Parotid gland o Structures within the parotid gland o Innervation of the parotid gland and related structures o Clinical correlations II. Temporal region o Temporal fossa o Infratemporal fossa o Temporomandibular joint (TMJ) o Muscles of mastication o Neurovasculature of infratemporal fossa o Clinical correlations III. Pterygopalatine region and Its contents 17  Temporomandibular Joint (TMJ) o The parotid and temporal regions and the infratemporal fossa collectively include the temporomandibular joint and the muscles of mastication that produce its movements. o Temporomandibular joint (TMJ) articulation: 1. Superior: Mandibular fossa and articular tubercle of the temporal bone 2. Inferior: Head of mandible 18 Temporomandibular Joint (TMJ) Type: Modified hinge type of synovial joint 19  Temporomandibular Joint (TMJ) o Movements 1. Depression 2. Elevation 3. Protrusion (Protraction) 4. Retrusion (Retraction) 5. Lateral movements 20  Temporomandibular Joint (TMJ) Head of mandible เคลือ= นมาที= articular tubercle of Head of mandible อยูท่ ี= mandibular fossa of zygomatic process of temporal bone ทําให้ เกิดการ zygomatic process of temporal bone เคลือ= นไปด้ านหน้ าของ mandible และกด mandible ลง 21 Temporomandibular Joint (TMJ) (TMM) 22  Temporomandibular Joint (TMJ) Lateral ligament* o Supporting 1. Lateral (temporomandibular) ligament 2. Stylomandibular ligament 3. Sphenomandibular ligament 23  Temporomandibular Joint (TMJ) o Arterial supply o Branches of the external carotid artery, principally the superficial temporal branch. o Other contributing branches include deep auricular, ascending pharyngeal and maxillary arteries o Nerve supply o Auriculotemporal and masseteric branches of the mandibular nerve (CN V3) 24  Clinical Correlations: Dislocation of TMJ o Sometimes during yawning or taking a large bite, excessive contraction of the lateral pterygoids may cause the heads of the mandible to dislocate anteriorly (pass anterior to the articular tubercles). In this position, the mandible remains depressed and the person is unable to close his or her mouth. o Most common, a sideways blow to the chin by a clenched hand (fist) when the mouth is open dislocates the TMJ on the side that received the blow. o Because of the close relationship of the facial and auriculotemporal nerves to the TMJ, care must be taken during surgical procedures to preserve both the branches of the facial nerve overlying it and the articular branches of the auriculotemporal nerve that enter the posterior part of the joint. 25  OUTLINE I. Parotid region o Parotid gland o Structures within the parotid gland o Innervation of the parotid gland and related structures o Clinical correlations II. Temporal region o Temporal fossa o Infratemporal fossa o Temporomandibular joint (TMJ) o Muscles of mastication o Neurovasculature of infratemporal fossa o Clinical correlations III. Pterygopalatine region and Its contents 26  Muscles of Mastication o TMJ movements are produced chiefly by the muscles of mastication: o Masseter o Temporalis All are innervated by CN V3 o Lateral pterygoid (Mandibular branch of o Medial pterygoid trigeminal nerve) 27  Muscles of Mastication 1. Temporalis o Origin: Triangular muscle with broad attachment to floor of temporal fossa and deep surface of temporal fascia o Insertion: Narrow attachment to tip and medial surface of coronoid process and anterior border of ramus of mandible o Innervation: Anterior trunk of mandibular nerve (CN V3) via deep temporal branches o Action: Elevates mandible, closing jaws 28  Muscles of Mastication 2. Masseter o Origin: Quadrate muscle attaching to inferior border and medial surface of maxillary process of zygomatic bone and the zygomatic arch o Insertion: Angle and lateral surface of ramus of mandible o Innervation: Anterior trunk of mandibular nerve (CN V3) via masseteric nerve o Action: Elevates mandible, closing jaws; superficial fibers make limited contribution to protrusion of mandible 29 Botulinum Toxin for Masseter Reduction 30  Muscles of Mastication 3. Lateral pterygoid o Origin: Two-headed muscle: (1) infra- temporal surface and crest of greater wing of sphenoid and (2) lateral surface of lateral pterygoid plate o Insertion: Superior head attaches to joint capsule and articular disc of TMJ; inferior head attaches primarily to pterygoid fovea on anteromedial aspect of neck of condyloid process of mandible o Innervation: Anterior trunk of mandibular nerve (CN V3) via lateral pterygoid nerve o Action: Acting bilaterally, protracts mandible and depresses chin; acting unilaterally, swings jaw toward contralateral side; alternate unilateral contraction produces larger lateral chewing movements 31  Muscles of Mastication 4. Medial pterygoid o Origin: Two- headed muscle from (1) medial surface of lateral pterygoid plate and pyramidal process of palatine bone and (2) tuberosity of maxilla o Insertion: Medial surface of ramus of mandible, inferior to mandibular foramen o Innervation: Anterior trunk of mandibular nerve (CN V3) via medial pterygoid nerve o Action: Acts synergistically with masseter to elevate mandible; contributes to protrusion; alternate unilateral activity produces smaller grinding movements 32  OUTLINE I. Parotid region o Parotid gland o Structures within the parotid gland o Innervation of the parotid gland and related structures o Clinical correlations II. Temporal region o Temporal fossa o Infratemporal fossa o Temporomandibular joint (TMJ) o Muscles of mastication o Neurovasculature of infratemporal fossa o Clinical correlations III. Pterygopalatine region and Its contents 33  Neurovasculature of Infratemporal Fossa o Maxillary artery o The larger of the two terminal branches of the external carotid artery. o It arises posterior to the neck of the mandible and is divided into 3 parts based on its relation to the lateral pterygoid muscle. 1. Mandibular (1st part) 2. Pterygoid (2nd part) 3. Pterygopalatine (3rd part) 34 35 36  Neurovasculature of Infratemporal Fossa I. Mandibular artery (1st part of maxillary artery) 1. Deep auricular artery supplies external acoustic meatus, external tympanic membrane and TMJ 2. Anterior tympanic artery supplies internal aspect of tympanic membrane 3. Middle meningeal artery supplies tympanic cavity and tensor tympani muscle 4. Accessory meningeal artery supplies muscles of infratemporal fossa 5. Inferior alveolar artery supplies mandible, mandibular teeth, chin, mylohyoid muscle 37  Neurovasculature of Infratemporal Fossa o Relationship between middle meningeal artery and auriculotemporal nerve Note: Middle meningeal artery run through the twigs of auriculotemporal nerve 38  Neurovasculature of Infratemporal Fossa II. Pterygoid artery (2nd part of maxillary artery) 1. Masseteric artery supplies TMJ and masseter muscle 2. Deep temporal arteries; anterior and posterior artery supply temporalis muscle 3. Pterygoid branches: Irregular in number and origin; supply pterygoid muscles 4. Buccal artery supplies buccal fat-pad, buccinator and buccal oral mucosa 39  Neurovasculature of Infratemporal Fossa III. Pterygopalatine artery (3rd part of maxillary artery) 1. Posterior superior alveolar artery supplies maxillary molar and premolar teeth, adjacent gingiva 2. Infra-orbital artery supplies skin of infra- orbital region of face 3. Artery of pterygoid canal supplies mucosa of upper pharynx, pharyngo- tympanic tube and tympanic cavity 40  Neurovasculature of Infratemporal Fossa III. Pterygopalatine artery (3rd part of maxillary artery) 4. Pharyngeal branch supplies nasal roof, nasopharynx, sphenoidal air sinus 5. Descending palatine artery supplies mucosa and glands of hard and soft palate 6. Sphenopalatine artery: A terminal branch of maxillary artery supplies walls and septum of nasal cavity; frontal, ethmoidal, sphenoid, and maxillary sinuses; and anteriormost palate 41  Neurovasculature of Infratemporal Fossa o Pterygoid venous plexus o It is located partly between the temporalis and pterygoid muscles. o It is the venous equivalent of most of the maxillary artery—that is, most of the veins that accompany the branches of the maxillary artery drain into this plexus. o The plexus anastomoses anteriorly with the facial vein via the deep facial vein and superiorly with the cavernous sinus via emissary veins. The extensive nature and volume of the pterygoid venous plexus is difficult to appreciate in the cadaver, in which it is usually drained of blood. 42  Neurovasculature of Infratemporal Fossa o Mandibular nerve (CN V3) o It arises from the trigeminal ganglion in the middle cranial fossa and immediately receives the motor root of the trigeminal nerve and descends through the foramen ovale into the infratemporal fossa. o Branches of CN V3 are the 1. Auriculotemporal nerve- posterior division 2. Inferior alveolar nerve-posterior division 3. Lingual nerve-posterior division 4. Nerve to mylohyoid-posterior Note: Lingual and inferior alveolar nerves run in between division the medial and lateral pterygoid muscles. 5. Buccal nerve-anterior division Buccal nerve runs above the lateral pterygoid muscle. 43  Neurovasculature of Infratemporal Fossa 1. Auriculotemporal nerve Note: Middle meningeal artery o It encircles the middle run through the meningeal artery and twigs of auriculo- temporal nerve divides into numerous branches, the largest of which passes posteriorly, medial to the neck of the mandible, and supplies sensory fibers to the auricle and temporal region. o The auriculotemporal nerve also sends articular (sensory) fibers to the TMJ. It conveys postsynaptic parasympathetic secretomotor fibers from the otic ganglion to the parotid gland. 44  Neurovasculature of Infratemporal Fossa 2. Inferior alveolar nerve o It enters the mandibular foramen and passes through the mandibular canal, forming the inferior dental plexus, which sends branches to all mandi-bular teeth on its side. Another branch of the plexus, the mental nerve, passes through the mental foramen and supplies the skin and mucous Mental nerve membrane of the lower lip, the skin of the chin, and the vestibular gingiva of the mandibular incisor teeth. Note: Inferior alveolar nerve runs through the mandibular foramen, whereas, nerve to mylohyoid does not enter the mandibular foramen. 4545  Neurovasculature of Infratemporal Fossa 3. Lingual nerve o It lies anterior to the inferior alveolar nerve. It is sensory to the anterior two thirds of the tongue, the floor of the mouth, and the lingual gingivae. It enters the mouth between the medial pterygoid muscle and the ramus of the mandible and passes anteriorly under cover of the oral mucosa, medial and inferior to the 3rd molar tooth. 46  Neurovasculature of Infratemporal Fossa 3. Lingual nerve (cont’d.) o The chorda tympani nerve, a branch of CN VII carrying taste fibers from the anterior two thirds of the tongue, joins the lingual nerve in the infratemporal fossa. o The chorda tympani also carries secretomotor fibers for the submandibular and sublingual salivary glands. 47  Neurovasculature of Infratemporal Fossa 4. Buccal nerve o It is predominantly a sensory nerve, but may also carry the motor innervation to the lateral pterygoid muscle and to part of the temporalis muscle. o The buccal nerve passes laterally between the upper and lower heads of lateral pterygoid and then descend around the anterior margin of the ramus of mandible and continues to the cheek lateral to the buccinator muscle to supply general sensory nerves to the adjacent skin and oral mucosa and the buccal gingivae of the lower molars. Note: Buccal nerve is a sensory nerve. It does not supply the buccinator muscle. 48  Neurovasculature of Infratemporal Fossa o Otic ganglion o The otic ganglion (parasympathetic) is located in the infratemporal fossa, just inferior to the foramen ovale, medial to CN V3 and posterior to the medial pterygoid muscle. o Presynaptic parasympathetic fibers, derived mainly from the glossopharyngeal nerve, synapse in the otic ganglion. Postsynaptic parasympathetic fibers, which are secretory to the parotid gland, pass from the otic ganglion to this gland through the auriculo-temporal nerve. 49  OUTLINE I. Parotid region o Parotid gland o Structures within the parotid gland o Innervation of the parotid gland and related structures o Clinical correlations II. Temporal region o Temporal fossa o Infratemporal fossa o Temporomandibular joint (TMJ) o Muscles of mastication o Neurovasculature of infratemporal fossa o Clinical correlations III. Pterygopalatine region and Its contents 50  Pterygopalatine Fossa o Pterygopalatine fossa o An inverted ‘tear-drop’ shaped space between bones on the lateral side of the skull immediately posterior to the maxilla o It communicates via fissures and foramina in its walls with: 1. Middle cranial fossa 2. Infratemporal fossa 3. Floor of orbit 4. Lateral wall of the nasal cavity 5. Oropharynx 6. Roof of the oral cavity 51  Pterygopalatine Fossa o Pterygopalatine fossa (cont’d.) o It is a major site of distribution for the maxillary nerve (CN V2) and for the terminal part of the maxillary artery. o In addition, parasympathetic fibres from the facial nerve (CN VII) and sympathetic fibres originating from the T1 spinal cord level join branches of the maxillary nerve (CN V2) in the pterygopalatine fossa. o All the upper teeth receive their innervation and blood supply from the maxillary nerve (CN V2) and the terminal part of the maxillary artery, respectively, that pass through the pterygopalatine fossa 52  Pterygopalatine Fossa o Pterygopalatine fossa (cont’d.) o The walls of the pterygopalatine fossa are formed by parts of the palatine, maxilla, and sphenoid bones o Anterior wall: Posterior surface of the maxilla o Medial wall: Lateral surface of the palatine bone o Posterior wall and roof: Parts of the sphenoid bone Schematic drawing of left sided view (lateral to medial) of the pterygopalatine fossa 53  Pterygopalatine Fossa o Pterygoid canal *Pterygoid canal = Vidian canal o The pterygoid canal opens into the middle cranial fossa just anteroinferior to the internal carotid artery as the vessel enters the cranial cavity through the carotid canal 54  Pterygopalatine Fossa o Contents of pterygopalatine fossa 1. Pterygopalatine part of the maxillary artery 2. Maxillary nerve 3. Pterygopalatine ganglion and nerve of the pterygoid canal; this nerve enters the fossa carrying: o Preganglionic parasympathetic fibres from the greater petrosal branch of the facial nerve (CN VII) o Postganglionic sympathetic fibres from the deep petrosal branch of the carotid plexus 55  Pterygopalatine Fossa 1. Pterygopalatine part of the maxillary artery o The pterygopalatine part of the maxillary artery, its third part passes medially through the pterygomaxillary fissure and enters the pterygopalatine fossa. The artery lies anterior to the pterygopalatine ganglion and gives rise to branches that accompany all nerves entering and exiting the fossa. 56  Pterygopalatine Fossa 2. Maxillary nerve o Within the pterygopalatine fossa, the maxillary nerve gives off the zygomatic nerve, which divides into zygomaticofacial and zygomaticotemporal nerves. These nerves emerge from the zygomatic bone through cranial foramina of the same name and supply general sensation to the lateral region of the cheek and temple. 57  Pterygopalatine Fossa 2. Maxillary nerve (cont’d) o The zygomaticotemporal nerve also gives rise to a communicating branch, which conveys post- synaptic parasympathe- tic secretomotor fibers to the lacrimal gland by way of the heretofore purely sensory lacrimal nerve from CN V1 58  Pterygopalatine Fossa 3. Pterygopalatine ganglion and nerve of the pterygoid canal o The parasympathetic fibers to the pterygopalatine ganglion come from the facial nerve by way of its first branch, the greater petrosal nerve. This nerve joins the deep petrosal nerve as it passes through the foramen lacerum to form the nerve of the pterygoid canal, which passes anteriorly through this canal to the pterygo-palatine fossa. The parasympathetic fibers of the greater petrosal nerve synapse in the pterygopalatine ganglion. Note: Pterygoparatine ganglion is a collection of second order parasympathetic neurons that send axons supplying the nasal cavity, palate and lacrimal gland 59  Pterygopalatine Fossa 3. Pterygopalatine ganglion and nerve of the pterygoid canal Note: Greater petrosal nerve (parasym) + Deep petrosal nerve (sym) = Nerve of pterygoid canal 60 REFERENCES 1. Moore K.L. Clinically Oriented Anatomy 7th Ed. Lippincott Williams & Wilkins, Canada 2013 2. Drake R. L., Vogl W. and Mitchell A. W. M. Gray’s Anatomy for Students. Elsevier, China 2005 3. Netter F.H. Atlas of Human Anatomy 4th Ed. Elsevier, USA 2006 4. Halliday N.L. and Chung H.M. BRS Gross Anatomy 9th Ed. Wolters Kluwer, Mexico 2019 61  Dent NL Exam ผู้ป่วย fracture mandible ทีI angle zone ผู้ป่วยรู้สกึ ชาใบหน้ า lesion อยู่ ทีIเส้ นประสาทใด (Dent NL, 2014) 1. Infraorbital nerve 2. Buccal nerve 3. Lingual nerve 4. Inferior alveolar nerve Angle of mandible  Dent NL Exam นักศึกษาทันตแพทย์ตรวจการเคลือ5 นที5ของขากรรไกร อ้ า ปากกว้ างสุด กล้ ามเนื Bอใดหดตัว (Dent NL, 2015) 1) Anterior belly of digastric muscle 2) Buccinator 3) Depressor anguli oris 4) Medial pterygoid 5) Temporalis 63 Review Test A 37-year-old man receives a direct blow to his head and is brought to an emergency department. His radiograph shows a fracture of the floor of the middle cranial cavity, causing severance of the greater petrosal nerve. Which of the following conditions could be produced by this injury? A. Increased lacrimal gland secretion B. Loss of taste sensation in the epiglottis C. Dryness in the nose and palate D. Decreased parotid gland secretion E. Loss of sensation in the pharynx 64 Note: Greater petrosal nerve (parasym) + Deep petrosal nerve (sym) = Nerve of pterygoid canal 65 Review Test A 64-year-old woman is unable to open her mouth or jaw because of tetanus resulting from a penetrating wound from a rusty nail. Which of the following muscles would most likely be paralyzed? A. Masseter muscle B. Medial pterygoid muscle C. Lateral pterygoid muscle D. Buccinator muscle E. Temporalis muscle 66