Variations of the Uncinate Process Morphology Using Cone Beam Computed Tomography

The uncinate process is a key landmark, which is removed at the beginning of endoscopic sinus surgery. In addition, it has a great role in the ventilation of the middle meatus and sinuses. The aim of this study was to visualize and classify anatomic variations of the uncinate process using multiplanar reconstructed CBCT images.
In this cross-sectional/descriptive study, the CBCT images of paranasal areas of 120 patients (63 males and 57 females) >18 years of age were analyzed. The superior attachment of the uncinate process was observed and classified according to Landsberg and Friedman classification. Pneumatization of the uncinate process and its deviation toward the orbit’s floor were also noted. Data were analyzed with chi-squared test and kappa coefficient (α = 0.05).
No-attachment (blunt) type exhibited the highest prevalence rate (40.4%), followed by attachment to agger nasi cell (Type 2, 33.3%), to lamina papyracea (Type 1, 12.5%), to the middle concha (Type 6, 4.5%), and to the skull base (Type 5, 4.1%). Bifurcation of the uncinate process and concomitant attachment to lamina papyracea and the junction of the middle concha and the cribriform plate (Type 3) exhibited a prevalence rate of 2.9%. Attachment to the junction of the middle concha and cribriform plate (Type 4) were seen in 1.6% of cases. Attachment to the lower rim of the orbit was seen in 2.9% of the cases. The uncinate process pneumatization was seen in 7% of the cases; 3% of the cases exhibited atelectatic and hypoplastic maxillary sinuses.
Evaluation of anatomical variations of the uncinate process and its pneumatization before surgery is essential to prevent damage to the surrounding structures during surgery.