|Year : 2020 | Volume
| Issue : 3 | Page : 368-371
Evaluation of anatomical variants in paranasal sinuses with computed tomography in central India region
Pratapsingh Parihar1, Shraddha Patel2, Money Banssal1, Aditya Patel3, Akhilesh Parihar4, Swapnil Mohod2
1 Department of Radiology, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, Maharashtra, India
2 Department of Oral Medicine and Radiology, Sharad Pawar Dental College, Datta Meghe Institute of Medical Sciences (Deemed to be University), Sawangi (Meghe), Wardha, Maharashtra, India
3 Department of Conservative Dentistry, Jazan College of Dentistry, Jazan University, Kingdom of Saudi Arabia
4 Department of Critical Care, Appollo Hospital, Hydrabad, Telangana, India
|Date of Submission||22-Nov-2019|
|Date of Decision||26-Jan-2020|
|Date of Acceptance||17-Mar-2020|
|Date of Web Publication||1-Feb-2021|
Dr. Shraddha Patel
Assistant Professor, Department of Oral Diagnosis and Radiology, Sharad Pawar Dental College, DMIMS DU, Sawangi Meghe, Wardha
Source of Support: None, Conflict of Interest: None
Aim: This study aimed to assess the congenital anatomical variations in paranasal sinuses (PNS) and determine the incidence of these variants using helical computed tomography (CT) scan. Materials and Methods: The study included 477 cases in whom unenhanced CT of the brain and PNS was performed in the axial plane, complemented by reconstructed coronal and sagittal sections. These patients were then reviewed for anatomical variants of the PNS and their relation to sinusitis. The results were statistically analyzed by using descriptive and inferential statistics with Chi-square test and predictive values. Statistical Package for Social Sciences version 17.0 and GraphPad Prism 5.0 were used for analysis. Results: Among all the patients studied, deviated nasal septum was noted as the most common anatomical variant in 178 (37.3%) patients followed by concha bullosa in 124 (26%) patients. Other variations found were agger nasi cells in 109 (22.9%), paradoxical middle turbinate in 45 (9.5%), Haller's cells in 47 (9.8%), and Onodi cells in 34 (7.1%) patients. Other uncommon anatomical variants such as hypoplastic frontal sinus and hyperpneumatization of PNS were noted in eight (1.68%) and two (0.42%) patients, respectively. Conclusion: The presence of anatomical variants may predispose to sinus pathology. Radiologists must pay close attention to anatomical variants in the preoperative evaluation, which helps avoid possible complications and improves the success of management strategies.
Keywords: Anatomical variants, computed tomography, concha bullosa, paranasal sinus, sinusitis
|How to cite this article:|
Parihar P, Patel S, Banssal M, Patel A, Parihar A, Mohod S. Evaluation of anatomical variants in paranasal sinuses with computed tomography in central India region. J Datta Meghe Inst Med Sci Univ 2020;15:368-71
|How to cite this URL:|
Parihar P, Patel S, Banssal M, Patel A, Parihar A, Mohod S. Evaluation of anatomical variants in paranasal sinuses with computed tomography in central India region. J Datta Meghe Inst Med Sci Univ [serial online] 2020 [cited 2021 Mar 4];15:368-71. Available from: http://www.journaldmims.com/text.asp?2020/15/3/368/308540
| Introduction|| |
Paranasal sinuses (PNS) are the hollow, air-filled cavities located within the bones of the skull and face. Leonardo Da Vinci in Milan in 1489 was the first to prepare and draw the anatomical specimens of PNS. The first clear indication of the existence of PNS was provided by Berenger Del Carpi, an anatomist and a surgeon at the Bologna in the early 16th century. There are a set of four pairs of sinuses – frontal, maxillary, ethmoid, and sphenoid sinuses, which lie in the interior of the frontal, maxilla, ethmoid, and sphenoid bones, respectively. In 1600, Fallopius referred to the maxillary sinus and suggested that the sinus was absent in children until they reached maturity.
The most common anatomical variants found in PNS region are deviated nasal septum (DNS), concha bullosa, agger nasi cell, paradoxical middle turbinate, Onodi cell, and Haller's cells. Sinonasal inflammatory disease is a frequently encountered health problem. Conventionally, plain films were the modality of choice in the evaluation of sinus pathology. Clinical and radiographic emphasis was directed primarily to the maxillary and frontal sinuses. In recent years, it has become evident that sinusitis is primarily a clinical diagnosis. The role of imaging is to document the extent of disease, to answer questions regarding ambiguous cases, and to provide an accurate display of the anatomy of the sinonasal system.
A precise knowledge of the anatomy of the PNS and its anatomical variants is essential for the radio-clinicians. With the advent of functional endoscopic sinus surgery (FESS) and coronal computed tomography (CT) imaging,,, considerable attention has been directed toward paranasal region anatomy. Imaging now provides surgeons with a detailed “road map” for guiding the FESS procedure. Conventional radiology does not permit a detailed study of the nasal cavity and PNS, which has now largely been replaced by Computed Tomographic (CT) imaging. Currently, CT scanning is the standard imaging in the evaluation of the PNS. This gives an applied anatomical view of the region and of the anatomical variants that are very often found. The presence of anatomical variants may predispose to sinus pathology. However, it is also important for surgeons to be aware of variations that may predispose patients to increased risk of intraoperative complications. The proper radiological assessment of anatomical variants in the preoperative evaluation can help in avoiding possible complications and improve the success of management strategies. Hence, the present study was aimed to assess the congenital anatomical variations in PNS and determine the incidence of these variants using helical CT scan in Central Indian population.
| Materials and Methods|| |
The study was conducted at Acharya Vinoba Bhave Rural Hospital, affiliated to Jawahar Lal Nehru Medical College, Sawangi, Wardha, Maharashtra, India, for a total period of 24 months. Unenhanced CT of the brain and PNS was performed in the axial plane, complemented by reconstructed coronal and sagittal sections. These patients were then reviewed for anatomical variants of the PNS and their relation to sinusitis. The sample size was 477. All patients referred for CT scan of the brain and PNS were included in the study, and patients with congenital deformities; a history of previous surgery; trauma; and malignancy of the nose, PNS, or maxillofacial region were excluded from the study. CT scan was done with standard protocol of 5-cm slice thickness, 120 kVp, and 300–500 mA. Exposure parameter for PNS view thickness was 3 mm, and an increment of 1.5 mm was taken.
In all cases, the existence of the following variants was investigated:
- Nasal septum: Septal deviation
- Turbinates: Concha bullosa and paradoxical middle turbinate
- Ethmoid air cells: Agger nasi cells, Haller's cells, and Onodi cells (extramural sphenoid cells)
- Other variants: Hypoplastic frontal sinus and hyperpneumatization of sinuses.
Statistical analysis was done by using descriptive and inferential statistics using Chi- square test and predictive values. Statistical Package for the Social Sciences version 17.0 (Chicago, Illinois, USA) and GraphPad Prism 5.0 (Chicago, Illinois, USA) were used for the analysis. P < 0.05 was considered as the level of statistical significance.
The Institutional Ethics Committee of DMIMSDU has approved the Research work proposed to be carried out at Jawaharlal Nehru Medical College, Sawangi(M), Wardha. Date: 30th Nov 2016 with Reference no DMIMS(DU)/IEC/2016/765.
| Results|| |
DNS was noted as the most common anatomical variant in 178 (37.3%) patients followed by concha bullosa in 124 (26%) patients. Other variations found were agger nasi cells in 109 (22.9%), paradoxical middle turbinate in 45 (9.5%), Haller's cells in 47 (9.8%), and Onodi cells in 34 (7.1%) patients. Other uncommon anatomical variants such as hypoplastic frontal sinus and hyperpneumatization of PNS were noted in eight (1.68%) and two (0.42%) patients, respectively.
Out of 477 patients, 406 patients were having anatomical variants. No anatomical variants were present in 42 patients. A total of 29 patients studied out of 477 had no evidence of any anatomical variant or sinusitis.
| Discussion|| |
The PNS region is prone to a large variety of lesions including both the anatomical variants and congenital anomalies. CT is an important modality and has surpassed plain radiography in the evaluation of PNS. This is due to the better ability of the CT scan to display bone and soft tissue and to accurately define the regional anatomy., In the present study, an attempt has been made to study the importance of CT scan in the evaluation of the anatomical variants of the PNS.
Concha bullosa, the pneumatized middle turbinate, has been implicated as a possible etiological factor in the causation of recurrent chronic sinusitis. The presence of a concha bullosa has ranged between 4% and 80% in different studies; our data reported an incidence of 26%; among a total of 124 patients, 83 patients had unilateral and 41 had bilateral conch bullosa. The incidence is less when compared to that of other studies by Smith et al. (67.5%), Bolger et al. (53.4%), Stallman et al. (44%), and Thiagarajan et al. (42.5%).,,, There were also other studies which reported a less incidence of concha bullosa by Gupta et al. (11.5%), Baradaranfar and Labibi. (12.5%), Mamatha et al. (15%), Dua et al. (16%), and Adeel et al. (18.2%). Perez et al., Tantilipikorn et al., and Biswas et al. reported the incidence of concha bullosa as 24.5%, 23.48%, and 36%, respectively, which was almost similar to the prevalence in our study. The true concha bullosa is produced following pneumatization of both portions – the vertical lamina and inferior bulb of the middle nasal concha. Both lamellar pneumatization and conchal pneumatization were included in concha bullosa in our study; with these criteria, its incidence was 26%.
Nasal septal deviation
Nasal septal deviation is usually congenital but may be posttraumatic in some patients. Trauma to nose in early childhood leads to deflection of nasal septum. Trauma is an important etiological factor of DNS in children. It mainly effects the cartilage part at the caudal end of the nasal septum. Janarthan et al. classified DNS into the following seven types:
- Type I: Midline septum or mild deviations in vertical or horizontal plane,which do not extend throughout the vertical length of the septum
- Type II: Anterior vertical deviation
- Type III: Posterior vertical deviation
- Type IV: “S” septum – posteriorly to one side and anteriorly to the other
- Type V: Horizontal spur to one side with or without high deviation to the opposite side
- Type VI: Type V with a deep groove on the concave side
- Type VII: Combination of more than one type.
In the present study, the incidence of DNS was found in 178 patients (37.3%), among which 99 were right sided and the rest 79 were left sided. DNS was the most commonly occurring anatomical variant in the present study. Its incidence was less in our study as compared to the studies by Thiagarajan et al. (80%), Biswas et al. (78%), Gupta et al. (65.2%), Mamatha et al. (65%), Stallman et al. (65%), Perez et al. (58%), Baradaranfar et al. (45%), and Dua et al. (44%). Bolger et al. (18.8%), Wani et al. (25.33%), Smith et al. (19.4%), and Adeel et al. (26%),,,, all reported a lower incidence of DNS as compared to our study.
A turbinate that is concave medially rather than laterally is called paradoxical turbinate. The middle turbinate is the most commonly affected turbinate of all the three turbinates.
In the present study, it was found in 45 patients (9.5%) – 39 unilateral and 6 bilateral. The incidence of paradoxical middle turbinate in our study (9.5%) is almost similar to 10%, 10%, 10%, and 9.33% as reported by Perez et al., Dua et al., Biswas et al., and? Wani et al., respectively.
Agger nasi cells
Agger nasi cells lie just anterior to the anterosuperior attachment of the middle turbinate and frontal recess. These can invade the lacrimal bone or the ascending process of maxilla. These cells were present in 109 patients (22.9%) in the present study – 71 patients unilateral and the rest 38 patients bilateral. The incidence of agger nasi cells reported by Biswas et al. (18%) was almost similar to the incidence in the present study. The incidence is less when compared to 98.5% by Bolger et al., 40% by Dua et al., and 36% by Baradaranfar and Labibi, which can be due to no definitive criteria for the diagnosis of agger nasi cells.
Onodi cells are posterior ethmoid cells that extend posteriorly, laterally, and sometimes superiorly to sphenoid sinus, lying medial to the optic nerve.
The incidence of Onodi cells was observed 8–14% by Perezet aland 10.9% by Bolger et al. While it was found in 34 patients (7.1%) in present study. When compaired for side of occurrence we found it Unilaterally in 23 patients while in 11 patients it was bilaterally present. The incidence reported by Dua et al. (6%), Adeel et al. (7.8%) and Tantilipikom et al (8.33%) were close to present study. However, Gupta et al. (47.82%) reported a quite higher incidence of onodi cell which may be due to no definitive criteria for its diagnosis.
Haller's cells are ethmoid air cells that project beyond the limits of the ethmoid labyrinth into the maxillary sinus. They are considered as ethmoid cells that grow into the floor of the orbit and may narrow the adjacent ostium. (Kennedy and Zinreich, 1988, considered Haller's cells as ethmoid cells which are the air cavities projecting below the ethmoid bulla within the orbital floor in the region of the opening of the maxillary sinus.) 100 However, Bolger et al. broadened the term to include any cell located between the ethmoidal bulla, the orbital lamina of the ethmoid bone, and the orbital floor. 60 In the present study, Haller's cells were in 47 patients (9.8%) – 33 unilaterally and 14 bilaterally. Kennedy and Zinreich reported an almost similar incidence of 10%. Wani et al. (8.66%), Biswas et al. (8%), and Adeel et al. (9.1%) all reported a closer incidence of Haller's cells in comparison to the present study.
Hypoplastic frontal sinus
Other variants found in the present study were hypoplastic frontal sinus in eight patients (1.68%) and hyperpneumatization of sinuses in two patients (0.42%). Mamatha et al. (10%) and Tantilipikom et al. (6.06%) reported a higher incidence of hypoplasticfrontal sinus on comparison to our study.
Hyperpneumatization of sinuses
Hyperpneumatization of sinuses is also known as pneumosinus dilatans. It is an extremely rare condition in which there is abnormal dilatation and expansion of the sinus with associated bony erosion. It is of two types – idiopathic and secondary pneumosinus dilatans. Secondary pneumosinus dilatans have been found to be associated with multiple conditions such as planum meningiomas, optic nerve sheath meningioma, fibrous dysplasia, and ossifying fibroma where tumor invasion causes a weakening of the abutting bone, leading to sinus expansion and dilatation. We found it in two (0.42%) patients in our study.,,
In the present study, 370 (77.6%) patients had PNS mucosal abnormalities and 107 (22.4%) patients had no mucosal abnormalities. Anatomical variation was seen in 328 (88.6%) out of 370 patients with PNS mucosal abnormalities and 78 (72.8%) out of 107 patients without PNS mucosal abnormalities. In the present study, there were no anatomical variants or mucosal abnormality of the PNS in 29 (6%) patients. From this observation, our study reveals that the presence of anatomical variants may predispose to sinus pathology. However, it is also important for surgeons to be aware of variations that may predispose patients to increased risk of intraoperative complications.,,,,,,,,,,,
| Conclusion|| |
Anatomical variants are common in sinus region. Hence, radiologists must pay close attention to the anatomical variants in the preoperative evaluation. It is important for surgeons to be aware of variations that may predispose patients to increased risk of intraoperative complications and help avoid possible complications and improve the success of management strategies.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Wright J. A History of Laryngology and Rhinology. 2nd
ed. NewYork: Lea and Febiger; 1914.
Lund VJ, Rowe-Jones J. Surgical management of rhinosinusitis. Scott-Brown's Otorhinolaryngology, Head and Neck Surgery. 7th
ed., Vol. 2. London: CRC Press; 2008. p. 1478-96.
Sood VP. History of rhinology. Indian J Rhinol 2001;1:35-43.
Eviatar E, Gavriel H, Pitaro K, Vaiman M, Goldman M, Kessler A. Conservative treatment in rhinosinusitis orbital complications in children aged 2 years and younger. Rhinology 2008;46:334-7.
Mafee MF. Imaging of paranasal sinuses and rhinosinusitis. Clin Allergy Immunol 2007;20:185-226.
Zinreich SJ. Progress in sinonasal imaging. Ann Otol Rhinol Laryngol Suppl 2006;196:61-5.
Zinreich SJ. Paranasal sinus imaging. Otolaryngol Head Neck Surg 1990;103:863-8.
Katzenmeyer K, Pou A, Quinn's. Neoplasms of the nose and paranasal sinuses. Online Textbook of Otolaryngology. Texas: UTMB; 2000. Available from: https://www.utmb.edu/ot
. [Last accessed on 2000 Jun 17].
Heffner DK. Classification of human upper respiratory tract tumors. Environ Health Perspect 1990;85:219-29.
Hatipoglu HG, Cetin MA, Yüksel E. Concha bullosa types: Their relationship with sinusitis, ostiomeatal and frontal recess disease. Diagn Interv Radiol 2005;11:145-9.
Stallman JS, Lobo JN, Som PM. The incidence of concha bullosa and its relationship to nasal septal deviation and paranasal sinus disease. AJNR Am J Neuroradiol 2004;25:1613-8.
Smith KD, Edwards PC, Saini TS, Norton NS. The prevalence of concha bullosa and nasal septal deviation and their relationship to maxillary sinusitis by volumetric tomography. Int J Dent 2010;2010. pii: 404982.
Bolger WE, Butzin CA, Parsons DS. Paranasal sinus bony anatomic variations and mucosal abnormalities: CT analysis for endoscopic sinus surgery. Laryngoscope 1991;101:56-64.
Gupta Ak, Gupta B, Gupta N, Tripathi N. Computerized tomography of paranasal sinuses: A roadmap to endoscopic surgery: Clin Rhinol 2012;5:1-10.
Baradaranfar MH, Labibi M. Anatomic variations of paranasal sinuses in patients with chronic sinusitis and their correlation with CT scan staging. Acta Med Iran 2007;45:477-80.
Mamatha H, Shamasundar NM, Bharathi MB, Prasanna LC. Variations of ostiomeatal complex and its applied anatomy: A CT scan study. Indian J Sci Technol 2010;3:904-7.
Dua K, Chopra H, Khurana AS, Munjal M. CT scan variations in chronic sinusitis. Ind J Radiol Imag 2005;15:315-20.
Biswas J, Patil CY, Deshmukh PT, Kharat R, Nahata V. Tomographic evaluation of structural variations of nasal cavity in various nasal pathologies. Int J Otolaryngol Head Neck Surg 2013;2:129-34.
Koul SA. Deviated nasal septum in Kashmiri children. Indian J Otolaryngol Head Neck Surg 1994;46:183-6.
Janarthan R, Vinay K, Ram B, Sathavahana C, Jaswinder S, Vineeta R. Classification of nasal septum deviations – Relation to sinonasal pathology. Indian J Otolaryngol Head Neck Surg 2005;57:199-201.
Basith Y, Thiagarajan B. Role of anatomical obstruction in the pathogenesis of chronic sinusitis. Otolyrngol Online J 2012;2:7-15.
Adeel M, Rajput MS, Akhter S, Ikram M, Arain A, Khattak YJ. Anatomical variations of nose and para-nasal sinuses; CT scan review. J Pak Med Assoc 2013;63:317-9.
Vlckova I, White PS. Rapidly expanding maxillary pneumosinus dilatans. Rhinology 2007;45:93-5.
Dangore-Khasbage S, Bhowate R. Utility of the morphometry of the maxillary sinuses for gender determination by using computed tomography [Uzytecznosc morfometrii zatok szczekowych przy uzyciu tomografii komputerowej w ustalaniu plci]. Dental and Medical Problems 2018:55:411-7.
Kandukuri R, Phatak S. Evaluation of sinonasal diseases by computed tomography. J Clin Diagn Res 2016;10:9-12.
Dangore-Khasbage S, Bhowate R. Utility of the Morphometry of the Maxillary Sinuses for Gender Determination by Using Computed Tomography. Dent Med Probl 2018;55:411-7. Available from: https://doi.org/10.17219/dmp/99622
. [Last accessed on 2019 Dec 07].
Jain S, Deshmukh PT, Lakhotia P, Kalambe S, Chandravanshi D, Khatri M. Anatomical Study of the Facial Recess with Implications in Round Window Visibility for Cochlear Implantation: Personal Observations and Review of the Literature. Int Arch Otorhinolaryngol 2019;23: E281-91. Available from: https://doi.org/10.1055/s-0038-1676100
. [Last accessed on 2019 Sep 08].
Borle RM, Jadhav A, Bhola N, Hingnikar P, Gaikwad P. Borle's Triangle: A Reliable Anatomical Landmark for Ease of Identification of Facial Nerve Trunk during Parotidectomy. J Oral Biol Craniofac Res 2019;9:33-6. Available from: https://doi.org/10.1016/j.jobcr.2018.08.004
. [Last accessed on 2019 Oct 19].
Singam AP, Chaudhary A, Shrey S. Anatomical Landmark Guided versus Ultrasound-Guided Technique for Subclavian Vein Cannulation in Critically Ill Patients. J Krishna Inst Inst Med Sci Univ 2019;8:50-7.
Sandhu GS, Nagrale HR. Computed Tomography Evaluation of Brain in Chronic Alcoholics. J Neurosci Rural Pract 2020;11:63-71. Available from: https://doi.org/10.1055/s-0039-1700610
. [Last accessed on 2020 Feb 20].
Hingnikar P, Bhola N, Jadhav A, Sharma A. Mucormycosis of Maxillary Sinus in a Newly Diagnosed Case of Diabetes Mellitus. J Datta Meghe Inst Med Sci Univ 2019;14:397-400. Available from: https://doi.org/10.4103/jdmimsu.jdmimsu_170_19
. [Last accessed on 2019 Nov 16].
Taksande A, Meshram R, Yadav P, Lohakare A. Rare Presentation of Cerebral Venous Sinus Thrombosis in a Child. J Pediatr Neurosci 2017 12:389-92. Available from: https://doi.org/10.4103/JPN.JPN_109_17
. [Last accessed on 2019 Nov 16].
Dangore-Khasbage S, Bhowate R. Utility of the Morphometry of the Maxillary Sinuses for Gender Determination by Using Computed Tomography [Uzytecznosc Morfometrii Zatok Szczekowych Przy Uzyciu Tomografii Komputerowej w Ustalaniu Plci]. Dent Med Probl 2018;55:411-7. Available from: https://doi.org/10.17219/dmp/99622
. [Last accessed on 2019 Nov 16].
Jain S, Deshmukh PT, Lakhotia P, Kalambe S, Chandravanshi D, Khatri M. Anatomical Study of the Facial Recess with Implications in Round Window Visibility for Cochlear Implantation: Personal Observations and Review of the Literature. Int Arch Otorhinolaryngo 2019;23:E281-91. Available from: https://doi.org/10.1055/s-0038-1676100
. [Last accessed on 2019 Nov 16].
Gupta PP, Dhok AM, Shaikh ST, Patil AS, Gupta D, Jagdhane NN. Computed Tomography Evaluation of Craniovertebral Junction in Asymptomatic Central Rural Indian Population. J Neurosci Rural Pract 2020;11:442-7. Available from: https://doi.org/10.1055/s-0040-1712719
. [Last accessed on 2019 Nov 16].
Pote M, Phatak S, Thakare P. Computed Tomographic Evaluation of Intracerebral Hemorrhage. J Datta Meghe Inst Med Sci Univ 2019;14: 179-82. Available from: https://doi.org/10.4103/jdmimsu.jdmimsu_75_19
. [Last accessed on 2019 Nov 16].