Japanese Journal of Radiology

, Volume 33, Issue 5, pp 279–286 | Cite as

High resolution CT study of the chorda tympani nerve and normal anatomical variation

  • Dalveer SinghEmail author
  • Charlie Chia-Tsong Hsu
  • Gigi Nga Chi Kwan
  • Sandeep Bhuta
  • Matt Skalski
  • Rhondda Jones
Original Article



The aim of this study was to define the normal anatomical variation of the course of the CTN through the mastoid temporal bone on high resolution CT (HRCT).

Materials and methods

Retrospective review of 27 consecutive normal HRCT bilateral temporal bones (n = 54, 14 males and 13 females, mean age 41 years) reconstructed at 0.4-mm slice thickness specifically measuring (1) origin of CTN from the posterior genu of the facial nerve (CNVII) and (2) the lateral-most position of the CTN from the mastoid segment of CNVII.


The mean distance of the CTN origin from the mastoid segment of CNVII was 11.5 mm (standard deviation, SD = 3.2, 95 % CI 10.7–12.3) with no statistically significant difference between the left and right side observed (p = 0.08). The most lateral distance of the CTN from CNVII was a mean of 1.3 mm (SD = 0.6, 95 % CI 1.2–1.7), range 0–2.5 mm and again no statistical significance between contralateral sides was observed (p = 0.11). These measurements demonstrated an excellent level of agreement between observers as assessed by intraclass correlation calculation.


Reproducible measurements demonstrate variability of the CTN in both its origin from the mastoid segment of CNVII and its lateral-most course. Precise description of the course of the CTN with HRCT may be useful for planning of otologic surgery and limiting inadvertent nerve injury.


Chorda tympani nerve Petrous temporal bone Facial nerve Computed tomography 


Conflict of interest

The authors declare that they have no conflict of interest. Neither I nor my immediate family members have a financial relationship with a commercial organization that may have a direct or indirect interest in the content of this manuscript (DS, CC-TH, SB, MS, GNCK, RJ).


  1. 1.
    McManus LJ, Dawes PJ, Stringer MD. Clinical anatomy of the chorda tympani: a systematic review. J Laryngol Otol. 2011;125(11):1101–8.CrossRefPubMedGoogle Scholar
  2. 2.
    Standring S. Grayʼs anatomy: the anatomical basis of clinical practice. 40th ed. Edinburgh: Churchill Livingstone; 2008.Google Scholar
  3. 3.
    Curtin H, Sanelli P, Som PM. Temporal bone: embryology and anatomy. In: Som PM, Curtin HD, editors. Head and neck imaging. St. Louis: Mosby; 2003. p. 1057–92.Google Scholar
  4. 4.
    Chilla R, Bruner M, Arglebe C. Function of submaxillary gland following iatrogenic damage to chorda tympani nerve. Acta Otolaryngol. 1979;87(1–2):152–5.CrossRefPubMedGoogle Scholar
  5. 5.
    Jeppsson PH. Studies on the structure and innervation of taste buds. An experimental and clinical investigation. Acta Otolaryngol Suppl. 1969;259:1–95.PubMedGoogle Scholar
  6. 6.
    McManus LJ, Stringer MD, Dawes PJ. Iatrogenic injury of the chorda tympani: a systematic review. J Laryngol Otol. 2012;126(1):8–14.CrossRefPubMedGoogle Scholar
  7. 7.
    Saito T, et al. Long-term follow-up results of electrogustometry and subjective taste disorder after middle ear surgery. Laryngoscope. 2001;111(11 Pt 1):2064–70.CrossRefPubMedGoogle Scholar
  8. 8.
    Michael P, Raut V. Chorda tympani injury: operative findings and postoperative symptoms. Otolaryngol Head Neck Surg. 2007;136(6):978–81.CrossRefPubMedGoogle Scholar
  9. 9.
    Anagnostopoulou S, Venieratos D, Antonopoulou M. Temporomandibular joint and correlated fissures: anatomical and clinical consideration. Cranio. 2008;26(2):88–95.PubMedGoogle Scholar
  10. 10.
    Low HL, Redfern RM. Isolated chorda tympani injury following petrous temporal fracture. J Clin Neurosci. 2008;15(6):716–8.CrossRefPubMedGoogle Scholar
  11. 11.
    McManus LJ, Dawes PJ, Stringer MD. Surgical anatomy of the chorda tympani: a micro-CT study. Surg Radiol Anat. 2012;34(6):513–8.CrossRefPubMedGoogle Scholar
  12. 12.
    Parlier-Cuau C, et al. High-resolution computed tomography of the canals of the temporal bone: anatomic correlations. Surg Radiol Anat. 1998;20(6):437–44.CrossRefPubMedGoogle Scholar
  13. 13.
    Eliasziw M, et al. Statistical methodology for the concurrent assessment of interrater and intrarater reliability: using goniometric measurements as an example. Phys Ther. 1994;74(8):777–88.PubMedGoogle Scholar
  14. 14.
    Hayen A, Dennis RJ, Finch CF. Determining the intra- and inter-observer reliability of screening tools used in sports injury research. J Sci Med Sport. 2007;10(4):201–10.CrossRefPubMedGoogle Scholar

Copyright information

© Japan Radiological Society 2015

Authors and Affiliations

  • Dalveer Singh
    • 1
    Email author
  • Charlie Chia-Tsong Hsu
    • 1
  • Gigi Nga Chi Kwan
    • 1
  • Sandeep Bhuta
    • 1
  • Matt Skalski
    • 2
  • Rhondda Jones
    • 3
  1. 1.Department of Medical ImagingGold Coast University HospitalGold CoastAustralia
  2. 2.Southern California University of Health SciencesWhittierUSA
  3. 3.Division of Tropical Health and MedicineJames Cook UniversityTownsvilleAustralia

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