Abstract
Cadaveric dissections helps aspiring ear surgeon to learn anatomy of temporal bone so as to avoid injury to the many vital structures. Objectives are to study the course of facial nerve and its variation in 50 cases of temporal bone dissection. To study the various parameter of the tympanomastoid segments of facial nerve, its relation with the important middle ear structures and their variations. To study the incidence of anatomical variations such as dehiscence of bony canal of facial nerve, bony overhang in the oval window region. The Current study was conducted at Dept. of ENT Temporal bone lab. 50 temporal bones were dissected to study the various parameters of the tympano-mastoid segments of the facial nerve, its relations with the important middle ear structures and their anomalies. The present study was carried out from Jan 2016 to Jan 2019. Out of 50 bones dissected, 44 (88%) bones were well pneumatised and 6(12%) bones were sclerotic. Length of the tympanic segment varied from 7.8 to 11.88 mm with a mean of 9.47 mm (± 1.06 mm). In 17 bones (34%) length of the mastoid segment was 13.1–14 mm, in 12 bones (24%) the length was 14.1–15 mm, while in 10 bones (20%) it was 12–13 mm. In 6 bones (12%) it was 15.1–16 mm and < 12 mm in 5 other bones (10%). The distance of second genu from outer cortex varied from 17.87–23.67 mm with a mean of 19.64 mm (± 1.42 mm).Distance of chorda tympani from stylomastoid foramina varied from 3.4–7.8 mm with a mean of 5.69 mm (± 1.51 mm). The study has provided knowledge of anatomy of temporal bone and its pneumatization pattern, the anatomy of the facial nerve, its variations and their incidence, relation of various middle ear landmarks with the facial nerve and proficiency in dissection.
Similar content being viewed by others
References
Kharat RD, Golhar SV, Patil CKY (2009) Study of intratemporal course of facial nerve and its variations in 25 temporal bones dissection. Indian J Otolaryngol Head Neck Surg 61:39–42
Nager GT, Proctor B (1991) Anatomical variations and anomalies involving the facial canal. Otorhinol Clin N Am 24(3):531
Bibas T, Jiang D, Gleeson MJ Disorders of facial nerve. In: Scott-Browns otorhinolaryngology, head and neck surgery, vol 3, 7th edn. Hodder Arnold, pp 3870–891
Proctor B (1991) The anatomy of the facial nerve. Otolaryngol Clin N Am 24:479–504
Agarwal (1993) Thesis for M.S Examination, unpublished, personal communication
Guild SR (1949) Natural absence of part of the bony wall of the facial canal. Laryngoscope 59(668–74):13
Hough JV (1958) Malformation and anatomical variations seen in the middle ear during the operation for mobilization of the stapes. Laryngoscope 68(1337–79):14
Beddard D, Saungers HW (1962) Congenital defects in the fallopian canal. Laryngoscope 72:112–115
Yadav SP et al (2006) Surgical anatomy of tympano mastoid segment of facial nerve. Indian J Otolaryngol Head Neck Surg 58:27–30
Nager GT, Proctor B (1982) The facial canal: normal anatomy, variation and anomalies. Anatomical variations and anomalies involving the facial canal. Otorhinolaryngol Suppl 97:45–61
Wetmore SJ (1991) Surgical landmark for the facial nerve. Otolaryngol Clin N Am 24(3):505–530
Fowler EP (1961) Variations in the temporal bone course of the facial nerve. Laryngoscope 71:937–946
Acknowledgements
Study is conducted at ENT department of our institute thanks to all my seniors and entire colleague for their kind support.
Funding
No funding sources
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
None declared
Ethical approval
This study approved by the institutional ethical committee
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Jatale, S.P., Chintale, S.G., Kirdak, V.R. et al. Our Experience of Anatomical Variations of Facial Nerve in Cadaveric Temporal Bone Dissection. Indian J Otolaryngol Head Neck Surg 73, 271–275 (2021). https://doi.org/10.1007/s12070-020-01969-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12070-020-01969-9