Related Experiment Video
Updated: May 1, 2026

Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas
Published on: January 17, 2018
Clinically significant anatomical variants of the paranasal sinuses
Rashid Al-Abri1, Deepa Bhargava1, Wameedh Al-Bassam1
1ENT Division, Department of Surgery, P.O. Box 35, Al Khod 123, Muscat, Sultanate of Oman.
Objective:
Anatomic structural variations of the paranasal sinuses have a practical significance during surgical procedures conducted on the sinuses by otolaryngologists. This study aims to evaluate the prevalence of clinically significant anatomical variations of the paranasal sinuses.
Methods:
A prospective analysis of 435 computed tomography (CT) examinations of adult Omani patients was conducted to determine the prevalence of clinically significant anatomical variations of the paranasal sinuses. A total of 360 CT scans were included from January 2009 to January 2010.
Results:
The findings showed abnormal Agger nasi cells in 49% of cases (95% CI: 44-54%), concha bullosa in 49% (95% CI: 44-54%), Haller cells in 24% (95% CI: 18-31%), asymmetry in anterior ethmoidal roof 32% (CI: 29-37%), Onodi cells in 8% (CI: 5%-10%). The type of skull base were as follows; Type 1 was 30% (n=107; 95% CI: 25-35%), Type 2 was 34% (n=123; 95% CI: 29-39), and Type 3 was 36% (n=130; 95% CI: 31-41%). Many other surgically significant anatomical variations in small numbers (1-3) were incidentally identified.
Conclusion:
Knowledge of the presence of anatomical variations of the sinuses has a clinical significance as it minimizes the potential for surgical complications. There is an ethnical difference in the prevalence of anatomical variations. Further studies of anatomical variations with clinical disease correlations are needed.
Related Concept Videos
Anatomy of Respiratory System I: Upper Respiratory Tract
Nose and nasal cavity
The nose and nasal cavity represent the main external openings of the respiratory tract....
Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
Nose and Nasal Cavity
Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
Physical Assessment of the Respiratory Tract I: Health History
Subjective Data
Subjective data provides vital information about the patient's health history and symptoms. This data is typically collected through interviews in which patients describe their experiences, symptoms, and concerns.
Health history and...
Bone Markings
Articulating Projections
Articulating projections are found where two bones meet to form a joint. These structures are usually found at the ends of bones. The largest articulation is a rounded projection called the head, supported by a narrow neck at the ends of...

