Prevalence of anatomical variants in the clivus: fossa navicularis magna, canalis basilaris medianus, and craniopharyngeal canal

  • Seval BayrakEmail author
  • Duygu Göller Bulut
  • Kaan Orhan
Original Article



This study determined the prevalence of fossa navicularis magna (FNM), canalis basilaris medianus (CBM), and craniopharyngeal canal (CPC), the size of FNMs, and types of CBM using 3D computed tomography (CT) images.


A total of 1059 3D images [649 cone beam computed tomography (CBCT) and 410 CT] were evaluated in this study. The prevalence of FNM, CBM, and CPC, length, width, and depth of FNM, and type of CBM were assessed.


Overall, FNM was identified in 7.6%, CPC in 0.3%, and CBM in 2.5% of the study group. Type 2 (0.1%) and Type 6 (0.1%) are the least common CBM types. There was no significant difference between genders for depth and width measurements (p > 0.05), however, the length of FNM was significantly higher in males than females in CBCT images (p = 0.02).


FNM, CBM, and CPC are rare anatomical variants of clivus. However, they can facilitate spread of infection to the skull base or vice-versa. These types of anatomical variations should be known by radiologists to avoid unnecessary diagnosis and treatment procedures and to distinguish anatomic variations from pathological conditions.


Canalis basilaris medianus Clivus Craniopharyngeal canal Fossa navicularis magna 


Author contributions

Protocol Development: KO. Data Collection-Analysis: SB, KO. Manuscript Writing: DGB, SB. Manuscript Editing: KO.

Compliance with ethical standards

Conflict of interest

The authors declare that there is no conflict of interest.


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Copyright information

© Springer-Verlag France SAS, part of Springer Nature 2019

Authors and Affiliations

  • Seval Bayrak
    • 1
    Email author
  • Duygu Göller Bulut
    • 1
  • Kaan Orhan
    • 2
    • 3
  1. 1.Department of Dentomaxillofacial Radiology, Dentistry FacultyBolu Abant İzzet Baysal UniversityBoluTurkey
  2. 2.Dentomaxillofacial Radiology Department, Dentistry FacultyAnkara UniversityAnkaraTurkey
  3. 3.OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of MedicineUniversity of Leuven and Oral &Maxillofacial Surgery, University Hospitals LeuvenLeuvenBelgium

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