Research Article, J Otol Rhinol Vol: 6 Issue: 3
Prevalence of Anatomical Variants on Computed Tomography of Nose and Paranasal Sinuses
Bhatia JSS*, Behera Sk, Dalmia D and Kaur A
Department Of Otorhinolaryngology, Dr. Babasaheb Ambedkar Central Railway Hospital, Mumbai, India
*Corresponding Author : Dr. Jas Simran Singh Bhatia
Resident, department of otorhinolaryngology, Dr. Babasaheb Ambedkar Central Railway Hospital Byculla, Mumbai
E-mail: [email protected]
Received: March 24, 2017 Accepted: May 03, 2017 Published: May 10, 2017
Citation: Bhatia JSS, Behera Sk, Dalmia D, Kaur A (2017) Prevalence of Anatomical Variants on Computed Tomography of Nose and Paranasal Sinuses. J Otol Rhinol 6:3. doi: 10.4172/2324-8785.1000317
Objective: Aim of the study was to determine the prevalence of anatomical variations of nose and paranasal sinuses based on the findings seen on computed tomography.
Methodology: CT SCAN of the patients with sinonasal symptoms was performed for evaluation of the anatomical variants of nose and paranasal sinuses. The sections were then analysed for anatomical variations. The data collected was subjected to statistical analysis.
Results: The most commonly encountered anatomical variation was DNS, present in 86.25% (69) of patients. Pneumatised septum was present in 25% (20) of patients. Concha bullosa was present in 28.75% (23) while Concha lamella was seen in 17.5% (14) of patients. Paradoxical middle turbinate was present in 13.75% (11) while pneumatization of uncinate process in 10% (8), pneumatized superior turbinate in 5% (4), Haller cells in 8.75% (7), prominent Agger nasi cells in 15% (12), pneumatized crista gali in 8.75% (7), Onodi cells in 20% (16), pneumatization of anterior clinoid process in 17.5% (14) while pneumatization of greater wing of sphenoid/ pterygoid process was present in 11.25% (9) of patients.
Conclusion: It is very important to recognize the clinical and surgical significance of these variations. Thus, prior to FESS, imaging with CT scan is mandatory to evaluate the anatomy of PNS and its variations.
Keywords: Anatomical variations; Paranasal sinus; Computed tomography; Prevalence; Nose; FESS
Chronic rhinosinusitis (CRS) remains a common cause of morbidity and impaired performance at school or workplace. Chronic rhinosinusitis, in addition to physical discomfort, also causes a substantial economic burden to patient in terms of missed workdays due to physician or hospital visits [1,2]. A definitive diagnosis and timely intervention can reduce morbidity due to this disease. The complicated radiologic anatomy of the lateral nasal wall together with the most important anatomical variations is demonstrated and the underlying pathophysiologic principles of chronic recurrent sinusitis are discussed . Computed tomography (CT) is the method of choice for evaluating these cases, particularly in patients, requiring surgical intervention . It is also used to create intraoperative road maps.
Endoscopic surgery demands a meticulous assessment and a detailed description of both nasal and paranasal sinuses . Mastery of sinus anatomy and its variant features forms the basis from which radiologic interpretation begins. Familiarization with the radiologic landmarks and cross-sectional anatomy on patient CT scans, along with clinical correlation, can further enhance the reader’s ability to understand sinus CT findings. In addition to reviewing the scan to determine the presence of disease, CT scans of the sinuses can also be reviewed to evaluate potential areas of occlusion and variations of the patient’s sinus anatomy in the setting of surgical planning.
Materials and Methods
Patients attending the OPD of ENT department of DR.BABA SAHEB AMBEDKAR MEMORIAL HOSPITAL, MUMBAI were evaluated for the signs and symptoms of nose and paranasal sinuses pathologies. The patients having positive findings suggestive of nose and paranasal sinuses pathologies on clinical examination underwent diagnostic nasal endoscopy with 0 degree rigid Hopkins endoscope of Karl Storz. CT SCAN of the above patients was then performed for evaluation of the anatomical variants of nose and paranasal sinuses. Coronal sections were performed with the patients in prone position, with extended neck and the plane perpendicular to the infraorbitomeatal line. 1 mm cuts are taken from frontal sinus anteriorly to the sphenoid sinus posteriorly. The sections were then analysed for anatomical variations. The data collected was subjected to statistical analysis.
A total of 80 patients were included in the study. Majority of the patients were male- 56.25% (45) as compared to the females who were 43.75% (35). The mean age of the patients was 41years. The common symptoms of presentation were nasal blockage (77.5%), rhinorrhoea (48.75%), sneezing (20%) and headache (15%).
The most commonly encountered anatomical variation was DNS, present in 86.25% (69) of patients (Figure 1). Bony septal spur was present in 27.5% (22) of patients (Figure 2). Pneumatised septum was present in 25% (20) of patients (Figure 3).
Concha bullosa was present in 28.75% (23) of patients (Figure 4). Concha lamella was seen in 17.5% (14) of patients (Figure 5). Paradoxical middle turbinate was present in 13.75% (11) of patients (Figure 6).
Pneumatization of uncinate process was present in 10% (8) of patients (Figure 7). On the basis of attachment of superior end of uncinate process four types of variations was seen in our study. In 47.5% (38) of patients upper end of uncinate process was free which was either unilateral or bilateral. In 51.25% (41) of patients upper end of uncinate was attached to lamina papyracea i.e. type I (Figure 8). In type II uncinate, upper end was attached to ethmoidal roof, which was present in 18.75% (15) of patients (Figure 9). In 5% (4) of patients type III uncinate was found i.e. upper end was bent medially to get attached to middle turbinate (Figure 10).
Pneumatized superior turbinate was present in 5% (4) of patients (Figure 11). Paradoxically curved superior turbinate was present in 3.75% (3) of patients (Figure 12). Haller cells are present in 8.75% (7) of patients (Figure 13). Prominent Agger nasi cells are seen in 15% (12) of patients (Figure 14). Pneumatized crista gali was found in 8.75% (7) of patients (Figure 15). Onodi cells were seen in 20% (16) of patients (Figure 16). Pneumatization of anterior clinoid process was present in 17.5% (14) of patients (Figure 17). Pneumatization of greater wing of sphenoid/pterygoid process was present in 11.25% (9) of patients (Figure 18).
Keros type I of olfactory fossa was present in 73.75% (59) of patients (Figure 19). Keros type II of olfactory fossa was seen in 26.25% (21) of patients (Figure 20). None of our patients were having type III type of olfactory fossa.
Type I Optic nerve was seen in 78.75% (63) of patients (Figure 21). Type II type of Optic nerve was seen in 23.75% (19) of patients (Figure 22). Type III Optic nerve was seen in 3.75% (3) of patients (Figure 23). Type IV Optic nerve was seen in 1.5% (1) of patients (Figure 24).
Frontal cell type I was seen in 23.75% (19) of patients (Figure 25). Frontal cell type II was present in 26.25% (21) of patients (Figure 26). Frontal cell type III was present in 2.5% (2) of patients (Figure 27). None of the patient with frontal cell type IV was seen in our study.
Supraorbital cells were seen in 12.5% (10) of patients.
In our study DNS was the most common anatomical variation with prevalence rate of 86.25%. Prevalence of this particular anatomical variation ranging from 26%-78% has been reported [6-11]. In one study, Perez-Pinas et al.  considered DNS, when any visually detectable nasal deviation from the midline was seen and observed prevalence of it to be 80%. Septal spur was found to be prevalent in 27.5% of the study population. Chandel et al.  reported prevalence of septal spur in 11.6% in their study. The prevalence rate of pneumatised septum in our study was 25%. The prevalence rate reported between 5.2% - 13.04% in various studies [8-10] (Table 1).
|Study Name||Year||Dns||Septal Spur||Pneumatised Septum||Concha Bullosa||Pneumatised Uncinate||Paradoxical Middle Turbinate||Haller Cell||Prominent Agger Nasi Cell||Onodi Cell||Keros Olfactory Fossa Type I/Ii/Iii|
|Dua et al. ||2005||44||-||-||16||-||10||16||40||6||-|
|Mamatha et al. ||2010||65||-||-||15||-||-||17.5||50||-||-|
|Gupta et al. ||2012||65.2||-||13.04||11.5||-||1.44||3.62||-||47.82||50/47.10/2.89|
|Biswas et al. ||2013||78||-||12||36||6||10||8||18||-||-|
|Adeel et al. ||2013||26||-||5.2||18.2||5.2||14.3||9.1||-||7.8||-|
|Chandel et al. ||2015||75||11.6||-||32.5||-||40.8||5||2.5||-||-|
Table 1: Comparison of prevalence of anatomical variations.
Presence of concha bullosa in our study was 28.75% of population. It was reported to be prevalent in between 11.5% - 36% of population in various studies [6-11]. Pneumatised uncinate process as an anatomical variation was seen in 10% of patients, in the present study. Biswas et al.  and Adeel et al.  reported prevalence of 6% and 5.2% of population respectively. Paradoxical middle turbinate was seen in 13.75% of population in our study. It was reported to be prevalent in between 1.44% - 40.8% of population in various studies [6,8-11].
Keros type I olfactory fossa was most commonly present in our study i.e. in 73.75% of population. On other hand, Keros type II was present only in 26.25% while Keros type III was not found in any of the case of our study. AK Gupta et al.  in their study, has the frequency of the different types of Keros olfactory fossa at about 50%, 47.10 % and 2.89% respectively. Alazzawi S et al.  done a study in 2012 and found prevalence of Keros type I olfactory fossa in 80% of their population while 20% of their population was having Keros type II olfactory fossa . Nouraei et al.  reported that 92% of patients had Keros type I olfactory fossa in their study. Similarly Keros type I olfactory fossa was most frequently present in the studies done by Bista et al.  and Solares et al..
The success of functional endoscopic sinus surgery (FESS) depends on adequate knowledge of anatomy of paranasal sinus, which is variable. It is very important to recognize the clinical and surgical significance of these variations. Computed tomography of the paranasal sinus has improved the visualization of paranasal sinus anatomy and has allowed greater accuracy in evaluating paranasal sinus disease.
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