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Lingual Nerve Block (selective anesthesia for tongue and floor of mouth)

last modified on: Mon, 03/18/2024 - 08:57

see also: Glossopharyngeal nerve block (gag reflex, transoral vocal cord surgery)Maximum Recommended Doses and Duration of Local AnestheticsSuperior Laryngeal Nerve Blocks Instruction VideoOral Cavity and Oropharynx Protocols

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Balasubramanian et al (2017) suggested that the commonly used inferior alveolar nerve block (IANB) unnecessarily blocks all three branches of the inferior alveolar nerve when selective anesthesia of the tongue, floor of mouth and lingual mucoperiosteum is needed. Of the three terminal branches of the inferior alveolar nerve, the inferior alveolar nerve (supplying mandibular teeth) and the buccal nerve (supplying the skin over the buccinator, buccal mucous membrane and buccal gingiva of the molars) do not need anesthesia when the isolated block of the lingual nerve (supplying the lingual gingiva, mucosa of the anterior 2/3 of the tonuge, and floor of mouth) will suffice. These investigators describe isolated lingual nerve block as:

  • Point of insertion of needle is distal and 6-8 mm inferior to the lingual gingival margin of the second lower molar
  • The barrel of the syringe is place dover the contralateral incisor/canine region - angulated toward the second molar
  • The target area is the lingula nerve in the third molar region
  • The depth of penetration of the needle is 5-8 mm
  • The volume injected 0.5 cc

Balasubramanian et al (2017) suggested advantages to the selective lingual nerve block (LNB) that they compared to IANB are:

  • greater success rate wtih LNB due to easier and closer access to target area
  • less chance of post-injection trismus
  • exclusive anesthesia to target area

Inferior alveolar nerve blocks are common in dentistry. Anesthetics are delivered to the pterygomandibular space through wihch the lingual nerve and inferior alveolar nerve travel. The lingual nerve is often comprised of a single fascicle at the level of the lingula with 7-39 fascicles in the third molar area (Pogrel 2003). This small number of fascicles in the proximal segment of the lingual nerve has been proposed as the reason that injury to the nerve at this site involves the entire lingual nerve distribution rather than limited number of peripheral areas.

Injuries to the lingual nerve (LN) and inferior alveolar nerve (IAN) are rare in the course of performing IANB (inferior alveolar nerve blocks) but have been described and attributed to direct needle insetion, chemical trauma and hematoma. In addition to lingual nerve damage from inferior alveolar nerve block anesthesia, other causes of lingual nerve injury include third molar surgery, bone regenerative therapies of the posterior mandible, tonsillectomy, orthognathic surgery and salivary duct surgery. In addition, orotracheal intubation and laryngoscopy with pressure on the nerve have been reported (Pippi 2018). Counseling about the potential for nerve injury is important in describing risks to procedures in this region. Pippi et al related the symptoms that have resulted in legal action are somatosensory deficits (hypoesthesia, anesthesia, paresthesia, or dysesthesia) and taste alterations (hypogeusia, ageusia or dysgeusia). These authors identify correlative symptoms from lingual nerve injury to include: 'inability to keep food or liquid in the oral cavity, unintentional tongue crushing during chewing, difficulty speaking, burning sensation, pain, and alterations in phonation as well as in taste perception of food and drink."

Pogrel et al (2000) reported experience with 83 consecutive patients with altered sensation over the distribution of the lingual nerve, inferior alveolar nerve or both as a result of receiving an inferior alveolar nerve block - with their criteria of 'permanent' symptoms defined as altered sensation lasting from more than one year with no signs of improvement. This altered sensation was thought to result from the nerve block alone in that the surgery for which the block was done in each case was limited to restorative dentistry and therefore thought to not put the nerves at risk. Exploratory surgery was done in 5 of these 83 cases - and none of the five benefited, with two reporting pain to be worse after the exploratory surgery. Through creative analysis, Pogrel et al (2000) calculated permanent injury to result from an inferior alveolar nerve block to be 1 in 26,762 - and estimated that a full-time practitioner will, on average, find one patient in their career with a permenent nerve involvement following inferior alveolar nerve block.

Reported distance of the lingual nerve to the third molar alveolar ridge has ranged from 0.57 to 4.4 mm horizontally and 2.3 to 16.8 mm vertically (Pippi 2018). Chan et al (2010) identified in cadaver study the lingual nerve on average to be 9.6 mm below the mid-lingual protion of the second molar cementoenamel junction.

References

Iwanaga J, Choi P J, Vetter M, et al. (August 06, 2018) Anatomical Study of the Lingual Nerve and Inferior Alveolar Nerve in the Pterygomandibular Space: Complications of the Inferior Alveolar Nerve Block. Cureus 10(8): e3109. DOI 10.7759/cureus.3109

Balasubramanian S, Paneerselvam E, Guruprasad T, Pathumai M, Abraham S, Krishnakumar Raja VB.: Efficacy of Exclusive Lingual Nerve Block versus Conventional Inferior Alveolar Nerve Block in Achieving Lingual Soft-tissue Anesthesia. Ann Maxillofac Surg. 2017 Jul-Dec;7(2):250-255. doi: 10.4103/ams.ams_65_17.

Pogrel MA, Bryan J, Regezi J: Nerve damage associated with inferior alveolar nerve blocks . J Am Dent Assoc. 1995, 126:1150-1155. 10.14219/jada.archive.1995.0336

Pippi R, Spota A, Santoro M: Prevention of lingual nerve injury in third molar surgery: literature review. J Oral Maxillofac Surg. 2017, 75:890-900. 10.1016/j.joms.2016.12.040

Garisto GA, Gaffen AS, Lawrence HP, Tenenbaum HC, Haas DA: Occurrence of paresthesia after dental local anesthetic administration in the United States. J Am Dent Assoc. 2010, 141:836-844. 10.14219/jada.archive.2010.0281

Pippi R et al. Medicolegal Considerations Involving Iatrogenic Lingual Nerve Damage.J Oral Maxillofac Surg. (2018)

Pogrel MA, Schmidt BL, Sambajon V, Jordan RC: Lingual nerve damage due to inferior alveolar nerve blocks: A possible explanation. J Am Dent Assoc 134:195, 2003

Chan HL, Leong DJ, Fu JH, et al: The significance of the lingual nerve during periodontal/implant surgery. J Periodontol 81: 372, 2010

Pogrel MA, Thamby S.Permanent nerve involvement resulting from inferior alveolar nerve blocks.J Am Dent Assoc. 2000 Jul;131(7):901-7. Erratum in: J Am Dent Assoc 2000 Oct;131(10):1418.