Duplication of hypoglossal canal in North Indian human skulls
DOI:
https://doi.org/10.18203/2320-6012.ijrms20172423Keywords:
Duplication, Hypoglossal nerve, Hypoglossal canal, VariationsAbstract
Background: The hypoglossal canal is one among the permanent components of occipital bone of both human being and animal skull, which transmits the twelfth cranial nerve, meningeal branch of ascending pharyngeal artery and emissary veins. This is commonly known as anterior condylar canal. In some cases, this canal is divided by a bony spicule leading to a variant known as double hypoglossal canal. Such partition of hypoglossal canal predisposes the roots of twelfth cranial nerve to entrapment in the occipital bone during ossification which subsequently may leads to an alteration in the tongue movement as well as speech. The objectives of the present study were to obtain the incidence of the variant of double hypoglossal canal in north Indian population especially in Bihar and compare the incidence of such type of variation in skull of different parts of our country as well as various races of the world.
Methods: The present study was carried out on 110 undamaged dry adult human crania of unknown age and sex for any variations in the hypoglossal canal or incidence of double hypoglossal canal.
Results: We observed 15 cases (13.63%) of double hypoglossal canal in which 8 (7.27%) specimens had unilateral while 7 (6.36%) specimens had bilateral double hypoglossal canal. Double hypoglossal canal was more common in right side. In 5 cases (4.54%) unilateral bony spicules were seen.
Conclusions: The study about the hypoglossal canal and its different variation is very important to clinicians, anatomist, forensic experts as well as anthropologists too. The knowledge about the different dimensions of hypoglossal canal is also very essential for neurosurgeons and radiologist for the planning of the surgeries around the posterior cranial fossa for tumors like schwannoma of hypoglossal nerve and treatment of sleep apnea syndrome. Hence the detailed morphometric study of hypoglossal canal will be helpful for the planning of surgical intervention around the base of skull becomes easier and safer.
References
Wysocki J, Kobryn H, Bubrowski M, Kwiatkowski J, Reymond J, Skarzynska B. The morphology of the hypoglossal canal and its size in relation to skull capacity in man and other species. Folia Morphol. 2004;63(1):11-7.
Standring S. Head and Neck in grays anatomy: the anatomical basis of clinical practices, S. Standring, H. Ellis, J. C. Healy, D. Jhonson and A. Williams, Eds.; Churchill Livingtone, New York, USA, 40th ed; 2008:415:460.
Zaidi SHH, Gupta R, Usman N. A study of hypoglossal canal in north Indian crania. J Anat Soc India. 2011;60(2):224-6.
Wood Jones F. The non-metrical morphological characters of skulls as criteria for racial diagnosis. J Anat. 1993;68:96-108.
Canalis RF, Martin N, Black K, Ammirati M, Cheatham M, Bloch J, et al. Lateral approach to tumors of the craniovertebral junction. Laryngoscope. 1993;103:343-9.
Schwaber MK, Netterville JL, Maciunas R. Microsurgical anatomy of the lower skull base a morphometric analysis. Am J Otol. 1990;11:401-5.
Tanzer A. Roentgen diagnosis of hypoglossal nerve canal. Radiol. 1975;18:42-8.
Kaur J, Srivastava D, Singh D, Raheja S. The study of hyperostosic variants: significance of hyperostotic variants of human skulls in anthropology. Ana Cell Biol. 2012;45:268-73.
Kanda T, Kiritoshi T, Osawa M, Toyoda K, Oba H, Kotoku JI, et al. The incidence of double hypoglossal canal in Japanese: Evaluation with multislice computed tomography. PLoS ONE 2015;10(2):e0118317.
Osunwoke EA, Okoseimiema SC, Yorkhum KL, Uzomba GC. A study on the dimensions of hypoglossal canal in Southern Nigerian Crania. J Biol Agricult Health. 2014;4(4):78-81.
Jacob M, Avadhani R, Nair B, Nallathamby R, Soman MA. An original study on anatomical variations of hypoglossal canal. Int J Health Sci Res. 2014;4(12):339-41.
Bhuller A, Sanudo JR, Choi D, Abrahams PH. Intracranial course and relations of the hypoglossal nerve: an anatomic study. Surg Radiol Anat. 1998;20:109-12.
Mouri T. Divided hypoglossal canals in Japanese Macaques. Anthropol Sci. 1998;105(4):211-16.
Raghunath M, Singh R, Shende N, Pandey S. Bilateral internal triplication of hypoglossal canal. Int J Health Sci Res. 2015;5(7):445-7.
Singh V, Sethi R, Kharb P, Singh R. Bridging pattern of hypoglossal canal - reclassified. J Anat Soci India. 2014;63(2):31-4.
Tuli A, Mangal A, Dixit SG, Choudhry R, Sanghwan S. Incidence, morphology and clinical relevance of bony canals and vascular grooves in the paracondylar region of adult human skulls. J Clin Neurosci. 2008;15(6):689-92.
Siva NRS, Raja SK. Study of duplicated hypoglossal canal in South Indian human skulls. Int J Cur Res Rev. 2013;14(5):103-5.
