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Applied anatomy of maxillary nerve

  1. APPLIED ANATOMY OF MAXILLARY NERVE Presented by Anirban Mallik(B.D.S. 3rd year)
  2. INTRODUCTION  It is the nerve of maxillary process, that differentiates from first pharyngeal arch.  It is purely sensory; and is intermediate in size between ophthalmic and mandibular nerve.
  3. ORIGIN  Sensory root fibers of trigeminal nerve comprises of the central processes of ganglion cells located in trigeminal ganglion.  Sensory root fibers enter the concave portion of each crescent and the three sensory divisions of trigeminal nerve exit from the convexity.  The 2nd sensory division among these three is Maxillary Nerve.  It originates from the middle part of trigeminal ganglion in middle cranial fossa.
  4. Fig 1: Origin and Course of Maxillary nerve
  5. COURSE It gives off meningeal branch in middle cranial fossa which is sensory. The nerve runs forwards through lower part of lateral wall of cavernous sinus. The lateral wall here fuses with endosteal layer of dura mater at lateral margin of foramen rotundum. It has a short course below the root of pterygopalatine fossa to inferior orbital fissure.
  6. As it crosses pterygopalatine fossa, it gives off its main branches to pterygopalatine ganglion, posterior superior alveolar nerve and zygomatic branches. It then angles laterally in a groove on posterior surface of maxilla, entering the orbit through inferior orbital fissure. Within the orbit it occupies the infraorbital groove and becomes infraorbital nerve which courses anteriorly into the infraorbital canal. The maxillary nerve emerges on anterior surface of face through infraorbital foramen.
  7. INNERVATION Nasal mucosa,
  8. BRANCHES Maxillary nerve gives off branches in four regions: 1. Within the cranium 2. In the pterygopalatine ganglion 3. In the infraorbital canal 4. On the face.
  9. Branches Within the Cranium: Middle Meningeal Nerve:  Immediately after separating from trigeminal ganglion, the maxillary nerve gives off a small branch, middle meningeal nerve.  It travels with middle meningeal artery. It provides sensory innervation to the dura mater of anterior half of middle cranial fossa.
  10. Branches in the Pterygopalatine Fossa: i. Pterygopalatine nerves ii. Zygomatic nerves iii. Posterosuperior alveolar nerves.
  11. Pterygopalatine nerves: Two short nerves, that suspend the pterygopalatine ganglion.  They pass through the ganglion into its branches and also serve as a communication between pterygopalatine ganglion and maxillary nerve.  By way of ganglion, the maxillary nerve has the four branches carrying sensory, secretomotor and sympathetic fibers. 1.Orbital branches: Supply periosteum of orbit. 2.Nasal branches: Supply mucous membranes superior and middle conchae, the lining of
  12. posterior ethmoidal sinus and posterior portion of nasal septum. These convey postganglionic parasympathetic fibers from pterygopalatine ganglion to nasal glands. I. Nasopalatine nerve (long sphenopalatine nerve) II. Posterior superior lateral nasal nerves (short sphenopalatine nerves) 3. Palatine branches: a. Greater palatine nerves (or anterior palatine nerves) b. Lesser palatine nerves (or middle and posterior palatine nerves).
  13.  These branches provide sensory innervation to hard and soft palate. These branches also convey postganglionic parasympathetic fibers from pterygopalatine ganglion to palatal glands. 4. Pharyngeal branch: It provides sensory innervation to nasopharynx.
  14.  Zygomatic Nerves:  It provides sensory innervation to skin over zygomatic region.  These nerves also convey postganglionic parasympathetic fibers from pterygopalatine ganglion to lacrimal nerve and glands.  It is a terminal branch.  The zygomatic nerve enters zygomatic bone and divides into two branches a. Zygomaticotemporal nerve: It perforates temporal surface of zygomatic bone, pierces
  15. temporalis fascia and supplies skin above zygomatic arch (skin of side of forehead or the “hairless” skin of temple). b. Zygomaticofacial nerve: It perforates the facial surface of zygomatic bone and supplies skin over the bone (skin over the prominence of cheek). It carries secretomotor fibers from pterygopalatine ganglion for lacrimal gland.
  16. Posterosuperior Alveolar Nerves:  These nerves are two to three in number.  These descend from the main trunk of the maxillary nerve in the pterygopalatine fossa just before the mandibular division enter inferior alveolar canal.  They emerge through the pterygomaxillary fissure.  One of it’s branch provides sensory innervation to buccal gingiva in maxillary molar region and adjacent facial mucosal surfaces.
  17.  Other branch enters maxilla (along with a branch of internal maxillary artery) through the posterior or posterolateral wall of maxillary sinus, and provides sensory innervation to mucous membrane of sinus.  Continuing downward, this second branch provides sensory innervation to alveoli, periodontal ligaments and pulpal tissues of maxillary molars, with the exception of (25%) patients of mesiobuccal root of first molar.
  18. Branches in the Infraorbital Canal: In the infraorbital canal, the maxillary division gives two branches: 1. Middle superior alveolar nerve 2. Anterior superior alveolar nerve It supplies multiple small branches through orbital plate of maxilla to roof of maxillary sinus. 1. Middle superior alveolar nerve: It supplies adjacent mucosa of maxillary sinus; two premolars and mesiobuccal root of first molar, periodontal tissues, buccal soft tissue and bone in premolar region.
  19. 2.Anterior superior alveolar nerve: It is relatively larger branch. Within the anterior wall of maxillary sinus, provides innervation to central and lateral incisors and the canines as well as sensory innervation to periodontal tissues, buccal bone and buccal gingiva of these teeth.  In patients where middle superior alveolar nerve is absent, the anterior superior alveolar nerve provides sensory innervation to premolars and occasionally the mesiobuccal root of first molar.
  20. Branches on the Face:  Infraorbital nerve emerges on the face through infraorbital foramen, lies between levator labii superioris and levator anguli oris, divides into its terminal branches. i. Inferior palpebral supply skin of lower eyelid with sensory innervation to both surfaces of conjunctiva. ii. External nasal/lateral nasal provides sensory innervation to skin on lateral aspect of nose
  21. iii. Superior labial provides sensory innervation to skin and mucous membrane of whole of upper lip (and sometimes also the adjacent gingiva from midline to second premolar teeth).  Infraorbital nerve has many communications with local branches of 7th cranial nerve, i.e. facial nerve, these are for proprioceptive supply of nearby facial muscles.
  22. APPLIED ANATOMY  Maxillary nerve has an important role in Anesthesia.  Maxillary Anesthesia is of three types- 1.Local Infiltration 2.Field Block 3.Nerve Block
  23. Small terminal nerve endings in the area of the dental treatment are flooded with local anesthetic solution. Incision is then made into the same area in which the local anesthetic has been deposited 1.Local Infiltration
  24. Local anesthetic is deposited near the larger terminal nerve branches. Incision is then made into an area away from the site of injection of the anesthetic. Maxillary injections administered above the apex of the tooth to be treated are properly termed field blocks 2.Field Block
  25. Local anesthetic is deposited close to a main nerve trunk, usually at a distance from the site of operative intervention. Posterior superior alveolar, inferior alveolar, and nasopalatine injections are examples of maxillary nerve blocks. 3.Nerve Block
  26. Types of Injections: Supraperiosteal (infiltration) Periodontal ligament (PDL, intraligamentary) Intraseptal injection Posterior superior alveolar nerve block Middle superior alveolar nerve block Anterior superior alveolar nerve block Greater (anterior) palatine nerve block Nasopalatine nerve block Maxillary (second division) nerve block Anterior middle superior alveolar nerve block Palatal approach-anterior superior alveolar nerve block
  27. Supraperiosteal Injection  Nerves anesthetized– terminal branch of dental plexus  Areas anesthetized  Entire region innervated by the large terminal branches of this plexus
  28. Posterior superior alveolar nerve block  Nerves Anesthetized-  Posterior superior alveolar and its branches  Areas Anesthetized- 1) Pulps of the maxillary 3rd , 2nd and 1st molars 2) Buccal periodontium and bone overlying these teeth
  29. Anterior superior alveolar(ASA) nerve block  Nerves anaesthetized 1. ASA nerve 2. MSA nerve 3. Infraorbital nerve – inferior palpebral  -- lateral nasal  -- superior labial  Areas anaesthetized 1. Pulps of maxillary C.I. through canine on the injected side 2. Pulps of maxillary premolars(72% of patients) & mesiobuccal root of the molar
  30. Middle Superior Alveolar Nerve Block  Nerves anaesthetized: MSA & terminal branch  Areas anaesthetized 1. Pulps of maxillary 1st & 2nd premolar & mesiobuccal root of 1st molar(28%) 2. Buccal periodontal tissues & bone of these teeth
  31. Greater palatine nerve block  Nerves anesthetized  Greater palatine nerve  Areas anesthetized  Posterior portion of the hard palate & its overlying tissues  Anteriorly as far as the 1st premolar & medially to the midline
  32. Nasopalatine Nerve Block  Nasopalatine nerve block is an invaluable technique for palatal pain control.  In this administration of a minimum volume of anesthetic solution (maximally, one quarter of a cartridge), a wide area of palatal soft tissue anesthesia is achieved, thereby minimizing the need for multiple palatal injections.
  33. Anterior middle superior alveolar nerve block  Nerves anesthetized 1. ASA nerve 2. MSA nerve 3. Subdural dental nerve plexus of the ASA & MSA  Areas anesthetized 1. Pulpal anesthesia of maxillary C.I. canines & premolars 2. Buccal attached gingiva of these same teeth 3. Attached palatal tissues from midline to free gingival margin on the associated teeth
  34. Maxillary nerve block  Nerve Anesthetized Maxillary division of the trigeminal nerve.  Areas Anesthetized 1. Pulpal anesthesia of the maxillary teeth on the side of the block 2. Buccal periodontium and bone overlying these teeth 3. Soft tissues and bone of the hard palate and part of the soft palate, medial to midline 4. Skin of the lower eyelid, side of the nose, cheek, and upper lip. 
  35. Fig: Maxillary nerve block, High-tuberosity approach
  36. Palatal Approach-Anterior Superior Alveolar  Nerves Anesthetized: Nasopalatine, Anterior branches of the ASA  Areas Anesthetized:  Pulps of the maxillary central incisors, the lateral incisors, the canines  Facial periodontal tissue associated with these same teeth  Palatal periodontal tissue associated with these same teeth
  37. Fig: Palatal Approach-Anterior Superior Alveolar Area of needle insertion
  38. THE END