Extra middle turbinate lamellas: a suggested new classification

Abstract

Purpose: Proper knowledge of sinonasal configurations and anatomical structural variations is essential to perform safe endoscopic sinus surgery. Although common middle turbinate variations have been well described in literature, rare variations have not. The aims of this study are to revise the nomenclature of extra middle turbinate lamellas variations and suggest an easy classification system of these lamellas.

Method: A retrospective charts and medical records review was performed for consecutive cases that were diagnosed with extra lamella middle turbinate based on endoscopic and stander three-dimensional reconstruction computer tomography scan at a tertiary academic center. After extensive literature review, these lamellas were classified into four types depending on the presence or absence of uncinate process and their morphological configuration.

Result: Twenty-two subjects (mean age 35 years; 8 men and 14 women) were identified who had thirty extra middle turbinate lamellas. Nasal obstruction and discharge were the most common presenting symptoms. Accessory middle turbinate was the most common extra lamella been observed and bifid inferior turbinate was the least common. Ten patients (45 %) had an accompanied middle turbinate anatomical variations, 9 (41 %) had nasal septum deviation, 11 (50 %) had associated maxillary or ethmoid sinusitis and 5 (23 %) had hypoplastic maxillary sinus.

Conclusion: Extra middle turbinate lamella is a rare type of middle turbinate anatomical variation that can be diagnosed by careful endoscopic examination and a precise computer tomography scan review. These lamellas may have a significant association with mucosa pathologies and are commonly seen with other common middle turbinate variations. Correct description and the use of common terminology can help to further evaluate the incidence of lamellas, their pathophysiological role, and to avoid any intraoperative landmark confusion.

Keywords: Accessory; Anatomical variation; CT scan; Endoscopy; Middle turbinate; Secondary; Sinus surgery.