Anatomical variations in superior attachment of uncinate process and localization of frontal sinus outflow tract


  • Arun G. Department of Otorhinolaryngology, Sri Siddhartha Medical College, Tumakuru, Karnataka, India
  • Sanu P. Moideen Department of Otorhinolaryngology, Sri Siddhartha Medical College, Tumakuru, Karnataka, India
  • Mohan M. Department of Otorhinolaryngology, Sri Siddhartha Medical College, Tumakuru, Karnataka, India
  • Khizer Hussain Afroze M. Department of Anatomy Sri Siddhartha Medical College, Tumakuru, Karnataka, India
  • Aparna S. Thampy Department of Dentistry, Padmavathy Medical Foundation, Kollam, Kerala, India



Frontal recess, Uncinate process, FESS, OMC, Sinusitis


Background: Uncinate process (UP) is a part of ethmoid bone, which is a thin sickle shaped projection on the lateral wall of nose. UP extends from the frontal recess superiorly and inferiorly to the ethmoid process of inferior turbinate. Various studies have shown that superior attachment of uncinate process (SAUP) is the key to frontal recess region in endoscopic sinus surgeries (ESS). But these studies have yielded conflicting results, showing multiple patterns and classifications of superior attachment of uncinate process. Knowing the anatomic variations of SAUP will help the surgeon to plan the endoscopic sinus surgery and to avoid the unwanted complications. Hence this study was conducted to observe and classify the superior attachment of uncinate process and to localize the frontal sinus outflow tract.

Methods: We did a retrospective cross sectional study, consisting of 100 patients including both sexes, above the age of 10 years. We excluded pregnant ladies, patients with prior sinus surgeries, sinonasal tumours, nasal polyposis, and craniofacial trauma.  

Results: We observed Type I SAUP, in 67.5% (n=135) cases, Type II SAUP in 18.5% (n=37), Type III attachment in 9.5% (n =19) and Type IV in 4.5% (n=9). Bilaterally similar attachments observed in 96% cases. Rest of the cases (4%), the attachment patterns was varying between sides.

Conclusions: The site of SAUP is highly variable. The most common type of SAUP is Type I (67.5%) followed by Type II (18.5%), Type III (9.5%) and Type IV (4.5%).

Author Biography

Arun G., Department of Otorhinolaryngology, Sri Siddhartha Medical College, Tumakuru, Karnataka, India

Senior Resident, Department of ENT


Yoon JH, Kim KS, Jung DH, Kim SS, Koh KS, Oh CS, Kim HJ, et al. Fontanelle and uncinate process in the lateral wall of the human nasal cavity. Laryngoscope. 2000;110(2):281.

Wormald PJ. Endoscopic Sinus Surgery: Anatomy, Three-Dimensional Reconstruction And Surgical Technique. 3rd edition. Thieme Medical Publishers Incorporated; 2013.

Peter-John W. Endoscopic Sinus Surgery Anatomy, Three-Dimensional Reconstruction, and Surgical technique. 3rd edition. 2013: 468.

Landsberg R, Friedman M. A computer-assisted anatomical study of the nasofrontal region. Laryngoscope. 2001;111:2125-30.

Moideen SP, Khizer Hussain Afroze M, Mohan M, Regina M, Moideen CP. Incidence of frontal sinus aplasia in Indian population. Int J Otorhinolaryngol Head Neck Surg. 2017;3:108-11.

Stammberger H. Functional Endoscopic Sinus Surgery: The Messerklinger Technique. Philadelphia: BC Decker; 1991: 60–87.

Kaliner MA, Osguthorpe JD, Fireman P, Anon J, Georgitis J, Davis ML, et al. Sinusitis: bench to bedside: current findings, future directions. J Allerg Clin Immunol. 1997;99(6):829-48.

Kennedy DW, Senior BA. Endoscopic Sinus Surgery. A review. Otolaryngol Clin North Am. 1997;30(3);313-30.

Stammberger HR, Kennedy DW. Anatomic Terminology Group. Paranasal sinuses: anatomic terminology and nomenclature. Ann Otol Rhinol Laryngol Suppl. 1995;167:7-16.

Peter JW. The agger nasi cell: the key to understanding the anatomy of the frontal recess. Otolaryngol Head Neck Surg. 2003;129(5):497-507.

Turgut S, Ercan I, Sayın I, Başak M. The relationship between frontal sinusitis and localization of the frontal sinus outflow tract: a computer-assisted anatomical and clinical study. Arch Otolaryngol Head & Neck Surg. 2005;131(6):518-22.

Netto B, Piltcher OB, Meotti CD, Lemieszek J, Isolan GR. Computed tomography imaging study of the superior attachment of the uncinate process. Rhinology. 2015;53(2):187-91.

Tuli IP, Sengupta S, Munjal S, Kesari SP, Chakraborty S. Anatomical variations of uncinate process observed in chronic sinusitis. Indian J Otolaryngol Head Neck Surg. 2013;65(2):157-61.

Kumar NV, Kamala E, Priya TG, Nalinakumari SD. A computerized tomographic study of uncinate process of ethmoid bone. Int J Anat Res. 2015;3(1):917-21.

Owen RG, Kuhn FA. The maxillary sinus ostium: Demystifying middle meatal antrostomy. Am J Rhinol. 1995;9(6):313-20.

Richtsmeier WJ. Top 10 reasons for endoscopic maxillary sinus surgery failure. Laryngoscope. 2001;111(11):1952-6.

Parsons DS, Stivers FE, Talbot AR. The missed ostium sequence and the surgical approach to revision functional endoscopic sinus surgery. Otolaryngologic Clin of North Am. 1996;29(1):169-83.






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