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Numb chin syndrome

Carrie Elizabeth Robertson, MD
Section Editor
Jerry W Swanson, MD, MHPE
Deputy Editor
John F Dashe, MD, PhD


Numb chin syndrome (NCS) was initially described in the 1830s by Charles Bell when he noted an absence of sensation in the left lower lip of a patient he was seeing for breast cancer. During her examination, he noted a palpable mass extending along the angle of her jaw, presumably into the mental foramen. The term "syndrome of the numb chin" did not arrive, however, until the 1960s when Calverley and Mohnac described five patients with chin numbness from various malignancies [1]. Though it is now understood that NCS may arise from a variety of conditions, it is the known potential association with malignancy that is most concerning.

Given the relatively small area involved, it is possible for both patients and clinicians to underemphasize this symptom. It is the goal of this topic to improve the understanding of the widespread differential of this potentially ominous sign. This topic will review the anatomy, clinical features, differential diagnosis, evaluation, and prognosis for NCS.


The inferior alveolar nerve travels through the medial surface of the mandible though the mandibular canal, dividing into the incisive and mental branches just anterior to the first premolar tooth (figure 1 and figure 2). The incisive branch innervates the first premolar, canine, and incisor teeth along with the associated vestibular gingiva. The mental nerve passes through the mental foramen on the anterior mandible, typically below the second premolar tooth, before dividing into two or three branches that supply sensation to the skin of the chin, the mucous membrane of the lower lip, and the buccal gingivae of the mandibular teeth and premolars [2,3]. These branches typically stop at midline [4].

Moving proximally, the inferior alveolar nerve is a branch off the posterior portion of the mandibular nerve, which passes through the foramen ovale before connecting to the trigeminal ganglion in Meckel's cave. This sends afferent sensory trigeminal fibers into the lateral pons, coursing dorsomedially to the principal sensory and spinal trigeminal nuclei in the brainstem.


Numb chin syndrome (NCS) can occur from a lesion anywhere along the course of the trigeminal nerve, including proximally within the Gasserian ganglion or even the nerve cell bodies within the pons [5]. Lesions can be broadly divided into peripheral lesions (involving the mandible or direct nerve infiltration, inflammation, or compression) and central lesions (involving the base of skull, leptomeninges, or brainstem). In the case of malignancy-associated NCS, neuropathy can be from direct infiltration of the nerve or mandible, such as from melanoma of the oral mucosa, or metastasis from a distant neoplasm.


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Literature review current through: Sep 2016. | This topic last updated: Jul 27, 2016.
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  1. CALVERLEY JR, MOHNAC AM. SYNDROME OF THE NUMB CHIN. Arch Intern Med 1963; 112:819.
  2. Rodella LF, Buffoli B, Labanca M, Rezzani R. A review of the mandibular and maxillary nerve supplies and their clinical relevance. Arch Oral Biol 2012; 57:323.
  3. Smith RM, Hassan A, Robertson CE. Numb Chin Syndrome. Curr Pain Headache Rep 2015; 19:44.
  4. Laurencet FM, Anchisi S, Tullen E, Dietrich PY. Mental neuropathy: report of five cases and review of the literature. Crit Rev Oncol Hematol 2000; 34:71.
  5. Iñiguez C, Mauri JA, Larrodé P, et al. [Mandibular neuropathy due to infiltration of the Gasser ganglion]. Rev Neurol 1997; 25:1092.
  6. Lossos A, Siegal T. Numb chin syndrome in cancer patients: etiology, response to treatment, and prognostic significance. Neurology 1992; 42:1181.
  7. Rubinstein MK. Cranial mononeuropathy as the first sign of intracranial metastases. Ann Intern Med 1969; 70:49.
  8. Massey EW, Moore J, Schold SC Jr. Mental neuropathy from systemic cancer. Neurology 1981; 31:1277.
  9. Peñarrocha Diago M, Bagán Sebastián JV, Alfaro Giner A, Escrig Orenga V. Mental nerve neuropathy in systemic cancer. Report of three cases. Oral Surg Oral Med Oral Pathol 1990; 69:48.
  10. Nobler MP. Mental nerve palsy in malignant lymphoma. Cancer 1969; 24:122.
  11. Raaphorst J, Vanneste J. Numb cheek syndrome as the first manifestation of anti-Hu paraneoplastic neuronopathy. J Neurol 2006; 253:664.
  12. Galán Gil S, Peñarrocha Diago M, Peñarrocha Diago M. Malignant mental nerve neuropathy: systematic review. Med Oral Patol Oral Cir Bucal 2008; 13:E616.
  13. Peñarrocha-Diago M, Mora-Escribano E, Bagán JV, Peñarrocha-Diago M. Neoplastic trigeminal neuropathy: presentation of 7 cases. Med Oral Patol Oral Cir Bucal 2006; 11:E106.
  14. Marsot-Dupuch K, Matozza F, Firat MM, et al. Mandibular nerve: MR versus CT about 10 proved unusual tumors. Neuroradiology 1990; 32:492.
  15. Hirshberg A, Shnaiderman-Shapiro A, Kaplan I, Berger R. Metastatic tumours to the oral cavity - pathogenesis and analysis of 673 cases. Oral Oncol 2008; 44:743.
  16. Abilleira S, Bowler JV. The numb chin syndrome as an early manifestation of giant-cell (temporal) arteritis: a case report. Headache 2005; 45:1411.
  17. Généreau T, Lortholary O, Biousse V, Guillevin L. Numb chin syndrome as first sign of temporal arteritis. J Rheumatol 1999; 26:1425.
  18. Oestmann A, Achtnichts L, Kappos L, et al. ["Numb chin syndrome": first presenting syndrome of multiple sclerosis?]. Dtsch Med Wochenschr 2008; 133:76.
  19. Khandaghi R, Arami MA. "Numb chin" as the first and sole presenting sign of multiple sclerosis. Arch Iranian Med 2005; 8:60.
  20. Shiroshita N, Kurosawa M, Okabe M, et al. [Multiple myeloma with numb chin syndrome as the initial manifestation]. Rinsho Ketsueki 1994; 35:792.
  21. Hiraki A, Nakamura S, Abe K, et al. Numb chin syndrome as an initial symptom of acute lymphocytic leukemia: report of three cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997; 83:555.
  22. Sasaki M, Yamazaki H, Aoki T, et al. Bilateral numb chin syndrome leading to a diagnosis of Burkitt's cell acute lymphocytic leukemia: a case report and literature review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 111:e11.
  23. Shahriar R, Alexander CT, Quirk CR, et al. Numb chin syndrome as the initial presentation of posttransplant lymphoproliferative disorder. Proc (Bayl Univ Med Cent) 2012; 25:243.
  24. Benito-León J, Simón R, Miera C. Numb chin syndrome as the initial manifestation of HIV infection. Neurology 1998; 50:511.
  25. Shen ML, Kang J, Wen YL, et al. Metastatic tumors to the oral and maxillofacial region: a retrospective study of 19 cases in West China and review of the Chinese and English literature. J Oral Maxillofac Surg 2009; 67:718.
  26. van der Waal RI, Buter J, van der Waal I. Oral metastases: report of 24 cases. Br J Oral Maxillofac Surg 2003; 41:3.
  27. Stypulkowska J, Bartkowski S, Pana's M, Zaleska M. Metastatic tumors to the jaws and oral cavity. J Oral Surg 1979; 37:805.
  28. Kumar G, Manjunatha B. Metastatic tumors to the jaws and oral cavity. J Oral Maxillofac Pathol 2013; 17:71.
  29. Bruyn RP, Boogerd W. Numb chin syndrome. Neurology 1993; 43:1058.
  30. Maillefert JF, Gazet-Maillefert MP, Tavernier C, Farge P. Numb chin syndrome. Joint Bone Spine 2000; 67:86.
  31. Bar-Ziv J, Slasky BS. CT imaging of mental nerve neuropathy: the numb chin syndrome. AJR Am J Roentgenol 1997; 168:371.
  32. Schmidt RF, Yick F, Boghani Z, et al. Malignant peripheral nerve sheath tumors of the trigeminal nerve: a systematic review of 36 cases. Neurosurg Focus 2013; 34:E5.
  33. Breshears JD, Ivan ME, Cotter JA, et al. Primary glioblastoma of the trigeminal nerve root entry zone: case report. J Neurosurg 2015; 122:78.
  34. Walter JM Jr, Gregg JM. Analysis of postsurgical neurologic alteration in the trigeminal nerve. J Oral Surg 1979; 37:410.
  35. Westermark A, Bystedt H, von Konow L. Inferior alveolar nerve function after mandibular osteotomies. Br J Oral Maxillofac Surg 1998; 36:425.
  36. Gianni AB, D'Orto O, Biglioli F, et al. Neurosensory alterations of the inferior alveolar and mental nerve after genioplasty alone or associated with sagittal osteotomy of the mandibular ramus. J Craniomaxillofac Surg 2002; 30:295.
  37. Nizam SA 2nd, Ziccardi VB. Trigeminal Nerve Injuries: Avoidance and Management of Iatrogenic Injury. Oral Maxillofac Surg Clin North Am 2015; 27:411.
  38. Tay AB, Go WS. Effect of exposed inferior alveolar neurovascular bundle during surgical removal of impacted lower third molars. J Oral Maxillofac Surg 2004; 62:592.
  39. Jerjes W, El-Maaytah M, Swinson B, et al. Inferior alveolar nerve injury and surgical difficulty prediction in third molar surgery: the role of dental panoramic tomography. J Clin Dent 2006; 17:122.
  40. Meyer RA, Bagheri SC. Nerve injuries from mandibular third molar removal. Atlas Oral Maxillofac Surg Clin North Am 2011; 19:63.
  41. Soikkonen K, Wolf J, Ainamo A, Xie Q. Changes in the position of the mental foramen as a result of alveolar atrophy. J Oral Rehabil 1995; 22:831.
  42. GOLDSTEIN NP, GIBILISCO JA, RUSHTON JG. Trigeminal neuropathy and neuritis. A study of etiology with emphasis on dental causes. JAMA 1963; 184:458.
  43. Assaf AT, Jürgens TP, Benecke AW, et al. Numb chin syndrome: a rare and often overlooked symptom. J Oral Facial Pain Headache 2014; 28:80.
  44. Willy PJ, Brennan P, Moore J. Temporary mental nerve paraesthesia secondary to orthodontic treatment--a case report and review. Br Dent J 2004; 196:83.
  45. Alsaad K, Lee TC, McCartan B. An anatomical study of the cutaneous branches of the mental nerve. Int J Oral Maxillofac Surg 2003; 32:325.
  46. Chan LL, DeMonte F, Ginsberg LE. Thermally induced transient trigeminal sensory neuropathy: imaging findings. AJNR Am J Neuroradiol 2000; 21:201.
  47. Orhan K, Bayndr H, Aksoy S, et al. Numb chin syndrome as a manifestation of possible breast cancer metastasis around dental implants. J Craniofac Surg 2011; 22:942.
  48. Bhatavadekar NB. Squamous cell carcinoma in association with dental implants: an assessment of previously hypothesized carcinogenic mechanisms and a case report. J Oral Implantol 2012; 38:792.
  49. Pfammatter C, Lindenmüller IH, Lugli A, et al. Metastases and primary tumors around dental implants: A literature review and case report of peri-implant pulmonary metastasis. Quintessence Int 2012; 43:563.
  50. Jané-Salas E, López-López J, Roselló-Llabrés X, et al. Relationship between oral cancer and implants: clinical cases and systematic literature review. Med Oral Patol Oral Cir Bucal 2012; 17:e23.
  51. Zadik Y, Benoliel R, Fleissig Y, Casap N. Painful trigeminal neuropathy induced by oral bisphosphonate-related osteonecrosis of the jaw: a new etiology for the numb-chin syndrome. Quintessence Int 2012; 43:97.
  52. Watt-Smith S, Mehta K, Scully C. Mefloquine-induced trigeminal sensory neuropathy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001; 92:163.
  53. Goodstein DB, Himmelfarb R. Allopurinol-induced mandibular neuropathy. Abbreviated case report. Oral Surg Oral Med Oral Pathol 1975; 40:51.
  54. Marey-López J, Sousa CP. Trigeminal sensory neuropathy related to interferon-alpha treatment. Muscle Nerve 2006; 33:581.
  55. Mitchell AB, Parsons-Smith BG. Trichloroethylene neuropathy. Br Med J 1969; 1:422.
  56. Albee RR, Nitschke KD, Mattsson JL, Stebbins KE. Dichloroacetylene: effects on the rat trigeminal nerve somatosensory evoked potential. Neurotoxicol Teratol 1997; 19:27.
  57. Ornsteen AM. Isolated bilateral trigeminal nerve disease presumably syphilitic in origin. J Nerv Ment Dis 1931; 74:297.
  58. . [Complete and isolated involvement of the right trigeminal nerve of syphilitic origin]. Toulouse Med 1950; 51:698.
  59. Maillefert JF, Dardel P, Piroth C, Tavernier C. Mental nerve neuropathy in Lyme disease. Rev Rhum Engl Ed 1997; 64:855.
  60. Yura Y, Kusaka J, Yamakawa R, et al. Mental nerve neuropathy as a result of primary herpes simplex virus infection in the oral cavity. A case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000; 90:306.
  61. Milam SB, Rees TD, Leiman HI. An unusual cause of bilateral mental neuropathy in an AIDS patient. Report of a case. J Periodontol 1986; 57:753.
  62. Chand V, Sweeney C, Agger WA. Mental neuropathy in patients with AIDS-associated malignant lymphoma. Clin Infect Dis 1997; 24:521.
  63. Alentorn A, Montero J, Vidaller A, Casasnovas C. Numb chin syndrome as an early symptom of primary and secondary vasculitis. Joint Bone Spine 2011; 78:427.
  64. Maillefert JF, Farge P, Gazet-Maillefert MP, Tavernier C. Mental nerve neuropathy as a result of hepatitis B vaccination. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997; 83:663.
  65. Kinno R, Ichikawa H, Tanigawa H, et al. Unilateral Abducens Nerve Palsy as an Early Feature of Multiple Mononeuropathy Associated with Anti-GQ1b Antibody. Case Rep Neurol 2011; 3:82.
  66. Hagen NA, Stevens JC, Michet CJ Jr. Trigeminal sensory neuropathy associated with connective tissue diseases. Neurology 1990; 40:891.
  67. Mori K, Iijima M, Koike H, et al. The wide spectrum of clinical manifestations in Sjögren's syndrome-associated neuropathy. Brain 2005; 128:2518.
  68. Dumas M, Pérusse R. Trigeminal sensory neuropathy: a study of 35 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999; 87:577.
  69. Quinones-Hinojosa A, Chang EF, Khan SA, McDermott MW. Isolated trigeminal nerve sarcoid granuloma mimicking trigeminal schwannoma: case report. Neurosurgery 2003; 52:700.
  70. Gupta M, Lascaratos G, Syrogiannis A, Esakowitz L. Isolated bilateral trigeminal neuropathy in sarcoidosis presenting with neurotrophic corneal ulcers. Ophthalmol Eye Dis 2010; 2:69.
  71. Bonnet F, Mercié P, Morlat P, et al. [Isolated involvement of the trigeminal nerve of sarcoidosis origin]. Rev Neurol (Paris) 1997; 153:59.
  72. DALY DD, LOVE JG, DOCKERTY MB. Amyloid tumor of the gasserian ganglion; report of case. J Neurosurg 1957; 14:347.
  73. Matsumoto T, Tani E, Fukami M, et al. Amyloidoma in the gasserian ganglion: case report. Surg Neurol 1999; 52:600.
  74. Bornemann A, Bohl J, Hey O, et al. Amyloidoma of the gasserian ganglion as a cause of symptomatic neuralgia of the trigeminal nerve: report of three cases. J Neurol 1993; 241:10.
  75. O'Brien TJ, McKelvie PA, Vrodos N. Bilateral trigeminal amyloidoma: an unusual case of trigeminal neuropathy with a review of the literature. Case report. J Neurosurg 1994; 81:780.
  76. Matsumoto K, Ueno M, Matsuo Y, et al. Primary solitary amyloidoma of the lung: findings on CT and MRI. Eur Radiol 1997; 7:586.
  77. Yamazaki Y, Ochi K, Nakata Y, et al. Trigeminal neuropathy from perineural spread of an amyloidoma detected by blink reflex and thin-slice magnetic resonance imaging. Muscle Nerve 2010; 41:875.
  78. Cruccu G, Agostino R, Inghilleri M, et al. Mandibular nerve involvement in diabetic polyneuropathy and chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 1998; 21:1673.
  79. Konotey-Ahulu FI. Mental-nerve neuropathy: a complication of sickle-cell crisis. Lancet 1972; 2:388.
  80. Mestoudjian P, Steichen O, Stankovic K, et al. Sickle cell disease, a benign cause of numb chin syndrome. Am J Med 2008; 121:e1.
  81. Kim TW, Park JW, Kim JS. A pitfall of brain MRI in evaluation of numb chin syndrome: mandibular MRI should be included to localize lesions. J Neurol Sci 2014; 345:265.
  82. Grisariu S, Avni B, Batchelor TT, et al. Neurolymphomatosis: an International Primary CNS Lymphoma Collaborative Group report. Blood 2010; 115:5005.
  83. Borges A, Casselman J. Imaging the trigeminal nerve. Eur J Radiol 2010; 74:323.
  84. Abramowicz S, Simon LE, Susarla HK, et al. Are panoramic radiographs predictive of temporomandibular joint synovitis in children with juvenile idiopathic arthritis? J Oral Maxillofac Surg 2014; 72:1063.
  85. Terumitsu M, Seo K, Matsuzawa H, et al. Morphologic evaluation of the inferior alveolar nerve in patients with sensory disorders by high-resolution 3D volume rendering magnetic resonance neurography on a 3.0-T system. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 111:95.
  86. Bromberg JE, Breems DA, Kraan J, et al. CSF flow cytometry greatly improves diagnostic accuracy in CNS hematologic malignancies. Neurology 2007; 68:1674.
  87. Bataineh AB. Sensory nerve impairment following mandibular third molar surgery. J Oral Maxillofac Surg 2001; 59:1012.
  88. Smith JH, Cutrer FM. Numbness matters: a clinical review of trigeminal neuropathy. Cephalalgia 2011; 31:1131.
  89. Ziccardi VB, Zuniga JR. Nerve injuries after third molar removal. Oral Maxillofac Surg Clin North Am 2007; 19:105.
  90. Ryba F, Rice S, Hutchison IL. Numb chin syndrome: an ominous clinical sign. Br Dent J 2010; 208:283.