Anatomical Variations of the Nasal Cavities and Paranasal Sinuses: A Systematic Review

Abstract

The anatomy of the nasal cavities and paranasal sinuses is one of the most varied in the human body. The aim of this study is to review the prevalence of anatomical variations in the sinonasal area. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We performed on PubMed a literature search from October 2004 until May 2020. The search strategy included the following keywords: (‘paranasal sinus’ OR ‘frontal sinus’ OR ‘maxillary sinus’ AND (‘anatomical variants’ OR ‘anomalies’)). Fifty studies were eligible and included in the analysis. Overall, the studies encompassed a total of 18,118 patients included in this review. Most common anatomical variations include agger nasi cells, nasal septum deviation and concha bullosa. Other variations seen in this region are uncinate process variations, paradoxical middle turbinate, Haller, Onodi and supraorbital ethmoid cells, accessory ostia of maxillary sinus. Less common variations include any sinus aplasia, crista galli pneumatization and dehiscence of the optic or maxillary nerve, internal carotid artery and lamina papyracea. Anatomical variations of this region also differ among ethnic groups. This study highlights the amount, variability and significance of most anatomical variants reported in the literature in the last years. It is essential for the sinus surgeon to have a broad spectrum of knowledge not only of “the typical” anatomy but also all the possible anatomical variations. With modern imaging modalities, anatomical variations can be detected, and uneventful pitfalls might be prevented.

Evaluation of Anatomical Variations of Paranasal Sinuses in Children with Coronal Plan Computed Tomography

“…The optic nerve is at risk in the presence of sphenoethmoid or Onodi cells during FESC. It is very important to specify in the radiological evaluation in order to prevent possible complications (3,16). The prevalence of Onodi cell ranges from 1.3-42%, in our study it was 11.6% (1,19).…”

“…It is thought that this cell is effective in the development of sinusitis by narrowing the infundibulum and maxillary sinus ostium. In addition, the presence of Haller cells may increase the risk of orbital injury during ethmoidectomy (16). The incidence of this variation in the pediatric group was found in previous studies as Milczuk 5.3%, Lusk 10%, April 18%, Aydın 6%, Palabiyik 10% and Sivaslı 30% (1,3,5,6,14,17).…”

“…It is the most common variation. Severe septal deviations may cause compression of the middle turbinate and obstruction of the middle meatus, leading to infection (3,11,16). Septum deviation has been reported between 4 and 96.9% in the literature.…”

“…Pneumatization of the UP is called "uncinate bulla". It has been suggested that pneumatized UP is associated with osteomeatal obstruction (12,16,21,24). It has been reported between 0.4% and 6% in the literature.…”

Pneumatization Patterns of the Sphenoid Sinus in Adult Nigerians and Their Clinical Implications

“…The sphenoid sinus is bounded by the hypophyseal fossa superiorly, the nasopharynx inferiorly, the cavernous sinus laterally, the ethmoidal sinus anteriorly, and the brainstem posteriorly ( 1 , 7 ). It is abutted by vital nerves and vessels such as the internal carotid artery and optic nerve whose positions in relation to the sphenoid sinus vary due to high interindividual variability in its pneumatization ( 8 , 9 ). The aeration ranges from minimal to extensive with potential involvement of the nearby structures that produce variant symptoms associated with sinus pathology.…”