CC BY-NC-ND 4.0 · Asian J Neurosurg 2024; 19(02): 202-209
DOI: 10.1055/s-0044-1787054
Research Article

The Prevalence of the Middle Clinoid Process: A Cross-Sectional Comparative Study in Patients with and without Pathology of the Sella Turcica

Suppaluk Anukulsampan
1   Division of Neurosurgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Chottiwat Tansirisithikul
1   Division of Neurosurgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
1   Division of Neurosurgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
› Author Affiliations


Background The middle clinoid process (MCP), particularly caroticoclinoid ring (CCR) type of the MCP, is an important part of the sphenoid bone for skull base surgery. Previous studies have shown a wide range of MCP prevalence affected by various factors. However, no study has investigated the association between the MCP and the presence of sellar lesions.

Objectives The main aim of this study was to evaluate the prevalence of the MCP in the Thai population and factors associated with its presence.

Materials and Methods We conducted a cross-sectional study on 400 sides from 200 patients (100 with and 100 without sellar lesions) using cranial computerized tomography scans. Demographic data and MCP characteristics were collected. The association between individual variables and the presence of the MCP was determined by univariate and multivariate analysis.

Results The MCP was identified in 168 of 400 sides (42%). Patients with sellar lesions had a significantly lower prevalence of the MCP compared with normal controls (29.5% versus 54.5%, p < 0.001). Of all MCP only 6% were the CCR type. Univariate and multivariate analysis showed that the absence of the sellar lesion was the only factor significantly associated with presence of the MCP (odds ratio: 2.86; 95% confidence interval: 1.90–4.32; p< 0.001).

Conclusion The prevalence of the MCP was relatively high in the Thai population, while the prevalence of the CCR was relatively low compared with previous studies. The absence of sellar lesions was the only factor associated with the presence of the MCP.

Publication History

Article published online:
05 June 2024

© 2024. Asian Congress of Neurological Surgeons. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

  • References

  • 1 Inoue T, Rhoton Jr AL, Theele D, Barry ME. Surgical approaches to the cavernous sinus: a microsurgical study. Neurosurgery 1990; 26 (06) 903-932
  • 2 Fernandez-Miranda JC, Tormenti M, Latorre F, Gardner P, Snyderman C. Endoscopic endonasal middle clinoidectomy: anatomic, radiological, and technical note. Neurosurgery 2012; 71 (2, suppl Operative): ons233-ons239
  • 3 Sharma A, Rieth GE, Tanenbaum JE. et al. A morphometric survey of the parasellar region in more than 2700 skulls: emphasis on the middle clinoid process variants and implications in endoscopic and microsurgical approaches. J Neurosurg 2018; 129 (01) 60-70
  • 4 Miller C, Chamoun R, Beahm D. Morphometric analysis of the middle clinoid process using maxillofacial computed tomography scans. Oper Neurosurg (Hagerstown) 2017; 13 (01) 124-130
  • 5 Keyes JEL. Observations on four thousand optic foramina in human skulls of known origin. Arch Ophthalmol 1935; 13 (04) 538-568
  • 6 Erturk M, Kayalioglu G, Govsa F. Anatomy of the clinoidal region with special emphasis on the caroticoclinoid foramen and interclinoid osseous bridge in a recent Turkish population. Neurosurg Rev 2004; 27 (01) 22-26
  • 7 Lee HY, Chung IH, Choi BY, Lee KS. Anterior clinoid process and optic strut in Koreans. Yonsei Med J 1997; 38 (03) 151-154
  • 8 Peris-Celda M, Küçükyürük B, Monroy-Sosa A, Funaki T, Valentine R, Rhoton Jr AL. The recesses of the sellar wall of the sphenoid sinus and their intracranial relationships. Neurosurgery 2013; 73 (2, suppl Operative): ons117-ons131
  • 9 Skandalakis GP, Koutsarnakis C, Pantazis N. et al. Caroticoclinoid bar: a systematic review and meta-analysis of its prevalence and potential implications in cerebrovascular and skull base surgery. World Neurosurg 2019; 124: 267-276
  • 10 Labib MA, Prevedello DM, Fernandez-Miranda JC. et al. The medial opticocarotid recess: an anatomic study of an endoscopic “key landmark” for the ventral cranial base. Neurosurgery 2013; 72 (1, suppl Operative): 66-76
  • 11 Wang J, Wang R, Lu Y, Yao Y, Qi S. Anatomical analysis on the lateral bone window of the sella turcica: a study on 530 adult dry skull base specimens. Int J Med Sci 2014; 11 (02) 134-141
  • 12 Pai DN, Chaitra D. Morphometric study of anterior clinoid process and its clinical importance in skulls of South Indian population. J Pharm Negat 2022; 13 (05) 1930-1933
  • 13 Suprasanna K, Ravikiran SR, Kumar A, Chavadi C, Pulastya S. Optic strut and para-clinoid region–assessment by multi-detector computed tomography with multiplanar and 3 dimensional reconstructions. J Clin Diagn Res 2015; 9 (10) TC06-TC09
  • 14 Purohit BJ, Singh PR. Incidence, anatomy and clinical significance of carotico-clinoid foramen and interclinoid osseous bridge in human skulls in Gujarat region. IntJ AnatRadiol Surg 2018; 7 (02) 33-37
  • 15 Priya A, Narayan RK, Ghosh SK, Kumar P. Morphometry and morphological analysis of carotico-clinoid foramen: an anatomical study with clinical implications. Folia Morphol (Warsz) 2023; 82 (01) 108-118
  • 16 Nikolova S, Toneva D, Zlatareva D, Fileva N. Osseous bridges of the sphenoid bone: frequency, bilateral and sex distribution. Biology (Basel) 2023; 12 (04) 492
  • 17 Ota N, Tanikawa R, Miyazaki T. et al. Surgical microanatomy of the anterior clinoid process for paraclinoid aneurysm surgery and efficient modification of extradural anterior clinoidectomy. World Neurosurg 2015; 83 (04) 635-643
  • 18 Gupta N, Ray B, Ghosh S. A study on anterior clinoid process and optic strut with emphasis on variations of caroticoclinoid foramen. Nepal Med Coll J 2005; 7 (02) 141-144
  • 19 Shaikh SI, Ukey RK, Kawale DN. et al. Study of carotico-clinoid foramen in dry human skull of Aurangabad district. Iran J Basic Med Sci 2013; 5 (03) 148-154
  • 20 Souza AD, Ankolekar VH, Nayak N, Hosapatna M, Souza AS. Morphometric study of anterior clinoid process and optic strut and the ossification of carotico-clinoid ligament with their clinical importance. J Clin Diagn Res 2016; 10 (04) AC05-AC07
  • 21 Jha S, Singh S, Bansal R, Chauhan P, Shah MP, Shah A. Nonmetric analysis of caroticoclinoid foramen in foothills of Himalayas: its clinicoanatomic perspective. Morphologie 2017; 101 (332) 47-51
  • 22 Suprasanna K, Kumar A. Surgically relevant bony anatomical variations in paraclinoid aneurysms-three-dimensional multi-detector row computed tomography-based study. J Neurosci Rural Pract 2017; 8 (03) 330-334
  • 23 Mizutani K, Toda M, Yoshida K. Analysis of the intercavernous sinus in sellar lesions using multidetector computed tomography digital subtraction venography. World Neurosurg 2016; 86: 336-340
  • 24 Dekaban AS. Tables of cranial and orbital measurements, cranial volume, and derived indexes in males and females from 7 days to 20 years of age. Ann Neurol 1977; 2 (06) 485-491
  • 25 Johnson DR, O'Higgins P, Moore WJ, McAndrew TJ. Determination of race and sex of the human skull by discriminant function analysis of linear and angular dimensions. Forensic Sci Int 1989; 41 (1-2): 41-53