The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization

Fondjo Teu’Mbou Sa’Deu; Zunon-Kipre Yvan Jacques-Olivier Toualy; Kakou Konan Medard; Veillon Francis; Nchufor Roland; Motah Mathieu

doi:doi:10.11648/j.ijn.20220602.16

The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization

Fondjo Teu’Mbou Sa’Deu, Zunon-Kipre Yvan Jacques-Olivier Toualy, Kakou Konan Medard, Veillon Francis, Nchufor Roland, Motah Mathieu

Published in International Journal of Neurosurgery (Volume 6, Issue 2)

Received: 23 August 2022 Accepted: 5 September 2022 Published: 11 October 2022

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Abstract

The labyrinthine segment of facial nerve canal and the geniculate ganglion fossa are two important landmarks in the middle cranial approach for acoustic neuromas removal. Their roof is drilled during this approach. The aim of the study was to appreciate the roof of these two structures on high-resolution computed tomography. To achieve this purpose, we used computed tomography examinations of 194 healthy adult petrous bones, selected within a period of one year. They represented 97 subjects with a mean age of 49.3 years. The computed tomography machines were Siemens® "SOMATOM Definition AS + Fast Care", 128 slices. The appreciated variable were t he presence or absence of a dehiscence, the thickness of the bone (mm), and the pneumatization of the bone (presence of aerated cells in the bone) or not (dense bone with total absence of aerated cells). We determined for each of these variables, the mean (mm), the standard deviation, the ranges (minimum, maximum). The paired Student’s t-test was used to compare the means of the variables according to gender (male-female), and side (right-left). We obtained the following results for the roof of the labyrinthine facial canal: all the canals (100%) were covered, 104 cases (53.6%) were pneumatized. The mean thickness of the bone was 3.86 mm ± 2.06, ranges 0.22 - 9.95 mm. Without male-female difference (p = 0.99 and p = 0.30), nor right-left difference (p = 0.07). For the geniculate ganglion fossa, 62 cases (31.96%) were dehiscent. One hundred and eight cases (81.81%) of the 132 covered cases were pneumatized. The mean thickness of the bone was 3.01 mm ± 1.87, ranges 0.36 - 9.12 mm. There was no male-female (p = 0.68 and p = 0.94) or left-right difference (p = 0.49). Our results therefore lead us to conclude that osseous covering of the geniculate ganglion is more prone to dehiscence and pneumatization than that of the labyrinthine facial canal, and thus presents more risks during surgery because of its fragility. So, we think that the bony covering should be studied for every patient in the event of middle fossa approach.

Published in	International Journal of Neurosurgery (Volume 6, Issue 2)
DOI	10.11648/j.ijn.20220602.16
Page(s)	56-66
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Labyrinthine Facial Canal, Geniculate Ganglion Fossa, Roof, Dehiscence, Pneumatization, Bone’s Thickness, High-Resolution Computed Tomography

References

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[2]	House WF, Hitselberger W. The middle fossa approach for removal of small acoustic tumors. Acta Otolaryngol. 1969; 138 (3): 272–87.
[3]	House WF, Gardner G, Hughes RL. Middle Cranial Fossa Approach to Acoustic Tumor Surgery: Unilateral Acoustic Tumors Confined to Internal Auditory Canal. Arch Otolaryngol. 1968; 88 (6): 631–41.
[4]	House WF, Crabtree JA. Surgical Exposure of Petrous Portion of Seventh Nerve. Arch Otolaryng. 1965; 81: 506–7.
[5]	Brackmann DE. Excision of Acoustic Neuromas by the Middle Fossa Approach. In: Rengachary SS, Wilkins RH, editors. Neurosurgical Operative Atlas - Volume 1. Park Ridge - Illinois: The American Association of Neurological Surgeons; 1991. p. 240–8.
[6]	Friedman RA, Brackmann DE. The middle cranial fossa approach to vestibular schwannomas. Oper Tech Neurosurg. 2001; 4 (1): 30–5.
[7]	House WF, Shelton C. Middle Fossa Approach for Acoustic Tumor Removal. Neurosurg Clin N Am. 2008; 19 (2): 279–88.
[8]	Rhoton AL, Pulec JL, Hall GM, Boyd AS. Absence of bone over the geniculate ganglion. J Neurosurg. 1968; 28 (1): 48–53.
[9]	Hall GM, Pulec JL, Rhoton AL. Geniculate Ganglion Anatomy for the Otologist. Arch Otolaryngol. 1969; 90 (5): 568–71.
[10]	Dobozi M. Surgical anatomy of the geniculate ganglion. Acta Otolaryngol. 1975; 80 (1–6): 116–9.
[11]	Rupa V, Weider DJ, Glasner S, Saunders RL. Geniculate ganglion: Anatomic study with surgical implications. Vol. 13, American Journal of Otology. 1992. p. 470–3.
[12]	Isaacson B, Vrabec JT. The radiographic prevalence of geniculate ganglion dehiscence in normal and congenitally thin temporal bones. Otol Neurotol. 2007; 28 (1): 107–10.
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[14]	Veillon F, William M, Casselmann J, Tomasinelli F, Riehm S, Moulin G, et al. Imagerie de l’os temporal normal. In: EMC-Radiologie et Imagerie Médicale : Musculo-squelettique-Neurologique-Maxillofaciale. 1994.
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[16]	Veillon F, Ramos L, Abu Eid M, Cahen-Riehm S, Szwarc D, Schultz P, et al. Imagerie du nerf facial. In: Imagerie de l’oreille et de l’os temporal - Tome 4 : Tumeurs, Nerf facial. Lavoisier. Paris: Médecine Sciences; 2014. p. 989–1041.
[17]	Elisabethinen K Der. Surgical Radiologic Anatomy multiplanar angulated 2-D-high-resolution CT-reconstruction. 1994; 423–7.
[18]	Di Martino E, Sellhaus B, Haensel J, Schlegel JG, Westhofen M, Prescher A. Fallopian canal dehiscences: A survey of clinical and anatomical findings. Eur Arch Oto-Rhino-Laryngology. 2005; 262 (2): 120–6.
[19]	Xian-Xi Ge, Spector GJ. Labyrinthine segment and geniculate ganglion of facial nerve in fetal and adult human temporal bones. Ann Otol Rhinol Laryngol. 1981; 90 (4 II Suppl. 85): 1–12.
[20]	Yetiser S. The Dehiscent Facial Nerve Canal. Int J Otolaryngol. 2012; 2012.

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Fondjo Teu’Mbou Sa’Deu, Zunon-Kipre Yvan Jacques-Olivier Toualy, Kakou Konan Medard, Veillon Francis, Nchufor Roland, et al. (2022). The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization. International Journal of Neurosurgery, 6(2), 56-66. https://doi.org/10.11648/j.ijn.20220602.16

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ACS Style

Fondjo Teu’Mbou Sa’Deu; Zunon-Kipre Yvan Jacques-Olivier Toualy; Kakou Konan Medard; Veillon Francis; Nchufor Roland, et al. The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization. Int. J. Neurosurg. 2022, 6(2), 56-66. doi: 10.11648/j.ijn.20220602.16

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AMA Style

Fondjo Teu’Mbou Sa’Deu, Zunon-Kipre Yvan Jacques-Olivier Toualy, Kakou Konan Medard, Veillon Francis, Nchufor Roland, et al. The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization. Int J Neurosurg. 2022;6(2):56-66. doi: 10.11648/j.ijn.20220602.16

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@article{10.11648/j.ijn.20220602.16,
  author = {Fondjo Teu’Mbou Sa’Deu and Zunon-Kipre Yvan Jacques-Olivier Toualy and Kakou Konan Medard and Veillon Francis and Nchufor Roland and Motah Mathieu},
  title = {The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization},
  journal = {International Journal of Neurosurgery},
  volume = {6},
  number = {2},
  pages = {56-66},
  doi = {10.11648/j.ijn.20220602.16},
  url = {https://doi.org/10.11648/j.ijn.20220602.16},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijn.20220602.16},
  abstract = {The labyrinthine segment of facial nerve canal and the geniculate ganglion fossa are two important landmarks in the middle cranial approach for acoustic neuromas removal. Their roof is drilled during this approach. The aim of the study was to appreciate the roof of these two structures on high-resolution computed tomography. To achieve this purpose, we used computed tomography examinations of 194 healthy adult petrous bones, selected within a period of one year. They represented 97 subjects with a mean age of 49.3 years. The computed tomography machines were Siemens® "SOMATOM Definition AS + Fast Care", 128 slices. The appreciated variable were t he presence or absence of a dehiscence, the thickness of the bone (mm), and the pneumatization of the bone (presence of aerated cells in the bone) or not (dense bone with total absence of aerated cells). We determined for each of these variables, the mean (mm), the standard deviation, the ranges (minimum, maximum). The paired Student’s t-test was used to compare the means of the variables according to gender (male-female), and side (right-left). We obtained the following results for the roof of the labyrinthine facial canal: all the canals (100%) were covered, 104 cases (53.6%) were pneumatized. The mean thickness of the bone was 3.86 mm ± 2.06, ranges 0.22 - 9.95 mm. Without male-female difference (p = 0.99 and p = 0.30), nor right-left difference (p = 0.07). For the geniculate ganglion fossa, 62 cases (31.96%) were dehiscent. One hundred and eight cases (81.81%) of the 132 covered cases were pneumatized. The mean thickness of the bone was 3.01 mm ± 1.87, ranges 0.36 - 9.12 mm. There was no male-female (p = 0.68 and p = 0.94) or left-right difference (p = 0.49). Our results therefore lead us to conclude that osseous covering of the geniculate ganglion is more prone to dehiscence and pneumatization than that of the labyrinthine facial canal, and thus presents more risks during surgery because of its fragility. So, we think that the bony covering should be studied for every patient in the event of middle fossa approach.},
 year = {2022}
}

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TY - JOUR
T1 - The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization
AU - Fondjo Teu’Mbou Sa’Deu
AU - Zunon-Kipre Yvan Jacques-Olivier Toualy
AU - Kakou Konan Medard
AU - Veillon Francis
AU - Nchufor Roland
AU - Motah Mathieu
Y1 - 2022/10/11
PY - 2022
N1 - https://doi.org/10.11648/j.ijn.20220602.16
DO - 10.11648/j.ijn.20220602.16
T2 - International Journal of Neurosurgery
JF - International Journal of Neurosurgery
JO - International Journal of Neurosurgery
SP - 56
EP - 66
PB - Science Publishing Group
SN - 2640-1959
UR - https://doi.org/10.11648/j.ijn.20220602.16
AB - The labyrinthine segment of facial nerve canal and the geniculate ganglion fossa are two important landmarks in the middle cranial approach for acoustic neuromas removal. Their roof is drilled during this approach. The aim of the study was to appreciate the roof of these two structures on high-resolution computed tomography. To achieve this purpose, we used computed tomography examinations of 194 healthy adult petrous bones, selected within a period of one year. They represented 97 subjects with a mean age of 49.3 years. The computed tomography machines were Siemens® "SOMATOM Definition AS + Fast Care", 128 slices. The appreciated variable were t he presence or absence of a dehiscence, the thickness of the bone (mm), and the pneumatization of the bone (presence of aerated cells in the bone) or not (dense bone with total absence of aerated cells). We determined for each of these variables, the mean (mm), the standard deviation, the ranges (minimum, maximum). The paired Student’s t-test was used to compare the means of the variables according to gender (male-female), and side (right-left). We obtained the following results for the roof of the labyrinthine facial canal: all the canals (100%) were covered, 104 cases (53.6%) were pneumatized. The mean thickness of the bone was 3.86 mm ± 2.06, ranges 0.22 - 9.95 mm. Without male-female difference (p = 0.99 and p = 0.30), nor right-left difference (p = 0.07). For the geniculate ganglion fossa, 62 cases (31.96%) were dehiscent. One hundred and eight cases (81.81%) of the 132 covered cases were pneumatized. The mean thickness of the bone was 3.01 mm ± 1.87, ranges 0.36 - 9.12 mm. There was no male-female (p = 0.68 and p = 0.94) or left-right difference (p = 0.49). Our results therefore lead us to conclude that osseous covering of the geniculate ganglion is more prone to dehiscence and pneumatization than that of the labyrinthine facial canal, and thus presents more risks during surgery because of its fragility. So, we think that the bony covering should be studied for every patient in the event of middle fossa approach.
VL - 6
IS - 2
ER -

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Author Information

Fondjo Teu’Mbou Sa’Deu

Neurosurgery Unit, Regional Hospital Maroua, Maroua, Cameroon
Zunon-Kipre Yvan Jacques-Olivier Toualy

Department of Fundamental Sciences and Bioclinics, Felix Houphouet-Boigny University, Abidjan, Ivory Cost
Kakou Konan Medard

Department of Fundamental Sciences and Bioclinics, Felix Houphouet-Boigny University, Abidjan, Ivory Cost
Veillon Francis

Imaging Unit 1, University Hospitals of Hautepierre, Strasbourg, France
Nchufor Roland

Neurosurgery Unit, Regional Hospital Bamenda, Bamenda, Cameroon
Motah Mathieu

Neurosurgery Unit, Laquintinie Hospital, Douala, Cameroon

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APA Style

Fondjo Teu’Mbou Sa’Deu, Zunon-Kipre Yvan Jacques-Olivier Toualy, Kakou Konan Medard, Veillon Francis, Nchufor Roland, et al. (2022). The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization. International Journal of Neurosurgery, 6(2), 56-66. https://doi.org/10.11648/j.ijn.20220602.16

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ACS Style

Fondjo Teu’Mbou Sa’Deu; Zunon-Kipre Yvan Jacques-Olivier Toualy; Kakou Konan Medard; Veillon Francis; Nchufor Roland, et al. The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization. Int. J. Neurosurg. 2022, 6(2), 56-66. doi: 10.11648/j.ijn.20220602.16

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AMA Style

Fondjo Teu’Mbou Sa’Deu, Zunon-Kipre Yvan Jacques-Olivier Toualy, Kakou Konan Medard, Veillon Francis, Nchufor Roland, et al. The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization. Int J Neurosurg. 2022;6(2):56-66. doi: 10.11648/j.ijn.20220602.16

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@article{10.11648/j.ijn.20220602.16,
  author = {Fondjo Teu’Mbou Sa’Deu and Zunon-Kipre Yvan Jacques-Olivier Toualy and Kakou Konan Medard and Veillon Francis and Nchufor Roland and Motah Mathieu},
  title = {The Roof of the Labyrinthine Facial Nerve Canal and the Geniculate Ganglion Fossa on High-Resolution Computed Tomography: Dehiscence, Thickness and Pneumatization},
  journal = {International Journal of Neurosurgery},
  volume = {6},
  number = {2},
  pages = {56-66},
  doi = {10.11648/j.ijn.20220602.16},
  url = {https://doi.org/10.11648/j.ijn.20220602.16},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijn.20220602.16},
  abstract = {The labyrinthine segment of facial nerve canal and the geniculate ganglion fossa are two important landmarks in the middle cranial approach for acoustic neuromas removal. Their roof is drilled during this approach. The aim of the study was to appreciate the roof of these two structures on high-resolution computed tomography. To achieve this purpose, we used computed tomography examinations of 194 healthy adult petrous bones, selected within a period of one year. They represented 97 subjects with a mean age of 49.3 years. The computed tomography machines were Siemens® "SOMATOM Definition AS + Fast Care", 128 slices. The appreciated variable were t he presence or absence of a dehiscence, the thickness of the bone (mm), and the pneumatization of the bone (presence of aerated cells in the bone) or not (dense bone with total absence of aerated cells). We determined for each of these variables, the mean (mm), the standard deviation, the ranges (minimum, maximum). The paired Student’s t-test was used to compare the means of the variables according to gender (male-female), and side (right-left). We obtained the following results for the roof of the labyrinthine facial canal: all the canals (100%) were covered, 104 cases (53.6%) were pneumatized. The mean thickness of the bone was 3.86 mm ± 2.06, ranges 0.22 - 9.95 mm. Without male-female difference (p = 0.99 and p = 0.30), nor right-left difference (p = 0.07). For the geniculate ganglion fossa, 62 cases (31.96%) were dehiscent. One hundred and eight cases (81.81%) of the 132 covered cases were pneumatized. The mean thickness of the bone was 3.01 mm ± 1.87, ranges 0.36 - 9.12 mm. There was no male-female (p = 0.68 and p = 0.94) or left-right difference (p = 0.49). Our results therefore lead us to conclude that osseous covering of the geniculate ganglion is more prone to dehiscence and pneumatization than that of the labyrinthine facial canal, and thus presents more risks during surgery because of its fragility. So, we think that the bony covering should be studied for every patient in the event of middle fossa approach.},
 year = {2022}
}

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