Paradoxical middle turbinate is a rare developmental cause of nasal obstruction. It refers to an inferomedially curved middle turbinate edge with the
concave surface facing the nasal septum, and usually occurs bilaterally.
Paradoxical middle turbinate is a rarely encountered anomaly and can be easily recognized in CT paransal sinuses but can be overlooked on endoscopic examination 3.
The prevalence reported by different authors may diverge because some of them consider any involved portion of the turbinate as paradoxical curvature, whereas others may consider this variation only in cases where the whole turbinate is unusually curved towards the opposite side 4.
Another study indicated paradoxical middle turbinate represents 9% of total anatomical variations.
The nasal turbinates are important structures of the nasal cavity. The inferior turbinates are considered a separate bone, conversely both the middle and superior turbinates are part of the ethmoid bone. Their position and relationship to other important anatomic landmarks is extremely important especially in skull base and ENT surgical procedures 1.
This anatomic variant alone can lead to significant narrowing of the middle nasal meatus and impede the normal drainage of paranasal sinuses due to ostiomeatal complex obstruction 2. When associated with a bulbous middle turbinate, it can potentially lead to nasal obstruction 2.
Treatment and prognosis
A study was done on 150 patients of chronic rhinosinusitis and found the following anatomical variants 5:
- concha bullosa (30%)
- posterior septal deviations (25%)
- uncinate process variations (25%)
- paradoxical middle turbinate (10%)
- agger nasi cells (10%)
- Haller cells (9%)
Functional endoscopic sinus surgery (FESS) has revolutionized the approach and treatment of chronic rhinosinusitis. Certain anatomical variations are thought to be predisposing factors for the development of sinus disease and it is necessary for the surgeon to be aware of these variations, especially if the patient is a candidate for FESS 5.
- 1. Măru N, Rusu MC, Săndulescu M. Variant anatomy of nasal turbinates: supreme, superior and middle conchae bullosae, paradoxical superior and inferior turbinates, and middle accessory turbinate. Rom J Morphol Embryol.56 (3): 1223-6. Pubmed citation
- 2. Neskey D, Eloy JA, Casiano RR. Nasal, septal, and turbinate anatomy and embryology. Otolaryngol. Clin. North Am. 2009;42 (2): 193-205, vii. doi:10.1016/j.otc.2009.01.008 - Pubmed citation
- 3. Ozcan KM, Selcuk A, Ozcan I et-al. Anatomical variations of nasal turbinates. J Craniofac Surg. 2008;19 (6): 1678-82. doi:10.1097/SCS.0b013e318188a29d - Pubmed citation
- 4. Riello A, Boasquevisque E. Variações anatômicas do complexo ostiomeatal: achados tomográficos em 200 pacientes. Radiologia Brasileira.41 (3): 149-154. doi:10.1590/S0100-39842008000300004
- 5. Wani AA, Kanotra S, Lateef M et-al. CT scan evaluation of the anatomical variations of the ostiomeatal complex. Indian J Otolaryngol Head Neck Surg. 2009;61 (3): 163-8. doi:10.1007/s12070-009-0059-8 - Free text at pubmed - Pubmed citation