The nasal septal deviation may either cause osteomeatal obstruction or may interfere with proper airflow and result in sinusitis. Nasal septal deviation disturbs nasal physiology, not always, but together with conchal hypertrophy or other anatomical variations. [1]. It could narrow the middle meatus by pushing the concha laterally. [2]. Besides nasal obstruction, it exerts pressure on neighboring structures. This disturbs the drainage pathways, affects the mucosal ciliary function by contact, and leads to obstruction and secondary nasal infections in all sinuses by disturbing normal mucus drainage. [3].

The nasal septum divides the nasal cavity into the left and right halves, both anatomically and physiologically. It is an accepted fact that some deviation of the nasal septum is common and having a perfectly straight septum is a rarity. [4]. Various reasons have been attributed to a deviated nasal septum, including racial factors, birth moulding of septum during parturition trauma, and developmental deformities of septum. [5]. The deviated nasal septum may cause nasal obstruction and symptoms of rhinosinusitis. Usually, paranasal air sinuses drain the mucous and fluid into the nose through various openings. [6].

An increased incidence and severity of bilateral chronic sinus disease were present with increasing deviations of the septum. [7]. Nasal septal deviation is a common disorder that presents in up to 62% of the population, and its role in the pathogenesis of chronic sinusitis remains uncertain. [8]. Hippocrates in the 5th century B.C stated that "In a person having a painful spot in the head, with intense headaches, pus or fluid running from the nose removes the disease", which may be referred to as describing sinusitis. [9].

Paranasal sinuses (PNS) are the air-containing cavities in the skull that surround the nasal cavity. The paranasal sinuses include maxillary, ethmoid, frontal, and sphenoid sinuses. [10]. The main functions of paranasal sinuses include lightening of the skull, air humidification, and voice resonance. [11]. There are various imaging modalities available for the evaluation of the paranasal sinuses. Conventional radiography has a limited role in the evaluation of nasal cavity, ethmoid and sphenoid sinuses because osteomeatal complexes are not delineated by traditional radiography. [12].

3. The CT scan images were studied to analyze the effect of increasing angle of septal deviation on the ipsilateral and contralateral lateral nasal wall structures, OMC patency, and the size and pattern of mucosal abnormalities in the paranasal sinuses.

Ethical Consideration and permission: After approval from Institutional Ethics Committee for Medical Research at Adesh Medical College and Hospital, the study was initiated.

Statistical analysis: The data analysis was done using M.S. excel categorical variables were presented in number and percentage (%).

In the present study, 35 were males (58.3%), and 25 were females (41.7%). The male to female ratio was 1.27: 1 (Table-1).

Table 1: Showing sex distribution

Table 2: Showing age distribution of patients studied

In table 2, only two patients were in the age group of ≤20 years (3.33%), followed by 14 of them in the age group of 21-30 years (23.3%) and 45 patients in the age group of 31-40 years (45%),

In table 6, the increasing angle of septal deviation was associated with an increase in the incidence of contralateral middle turbinate hypertrophy, and there was no evidence of ipsilateral middle turbinate hypertrophy in any of the three groups.

Three patients in group II and group III showed contralateral middle turbinate hypertrophy. Similarly, the incidence of contralateral inferior turbinate hypertrophy was also associated with increasing angles of septal deviation. Also, there was a higher incidence of bulbous type concha on the contralateral side in group II and group III patients.

Table 7: OMC obstruction and distribution of paranasal sinusitis among three groups.

In table 7, the most frequently involved sinusitis area was the maxillary sinusitis (40%), followed by osteomeatal complex (35%), then ethmoid sinusitis region (28.3%). Sphenoid sinusitis was least commonly involved (18.3%).

Table 8: Pattern of sinusitis and their distribution among three groups

In table 8, among the various sinus mucosal disease patterns, sinonasal polyposis pattern was the most common pattern (25%), followed by osteomeatal unit pattern (15%) and infundibular pattern (6.6%), and least was Sphenoethmoidal recess pattern (5%).

Three theories explain the pathophysiological relation between the deviated nasal septal and chronic sinusitis. The first is the mechanical theory which states that secretions accumulate in the sinus due to the narrowing of the ostiomeatal complex. Thus infections ensue in the retained secretions and cause chronic rhinosinusitis. The second theory is the aerodynamic theory.

In another study by Oudinet JP et al. (2006), nasal discharge was the commonest complaint seen in 78.2%, while nasal blockage and headache were seen in 75.6% of patients. [20]. In our study, deviated nasal septum to the left was more common than to the right side, accounting for 56.6% on the left side and 43.4% on the right side. Similar to our study, the study done by Moorthy P et al. in 2014 showed a deviation of the nasal septum to the left side (54%) more common than the right side (36.5%). [21]. This is similar to the study conducted by Uthman AT et al. The author studied the relation between the deviated nasal septum and paranasal sinus pathology. The study concluded that there is no significant association between deviated nasal and paranasal sinusitis. [22]. The maximum number of patients, 23 (38.3%), are group II angle of septal deviation, followed by the group I with 21 (35%) cases. The least number of patients, 16 (26.6%), are group III. These findings were following the study of Demir U.L., who reported a maximum number of cases 205 (34.8 %) to be of group I, followed by group II with 181 (30.7 %) cases and the least number of cases 4 (0.6 %) to be of group III angle of septal deviation. [23]. This suggests that people with horizontal spurs have a significantly increased probability of developing osteomeatal disease. These findings can be explained by the fact that due to the involvement of the nasal valve area, normal ventilation of the nose was hampered, leading to a high incidence of septal deviation in these groups. Our study shows a higher incidence of bulbous type concha on the contralateral side than the ipsilateral side among the three groups, parallel to the study results of Stallman et al. [24]. Aktas D et al. evaluated the association of septal deviation and chronic sinus disease. They concluded that the increasing angle of septal deviation is associated with bilateral sinus disease, contralateral middle turbinate abnormalities, and prominent ethmoidal bulla. [25]. However, in our study, this relationship was not observed. There was an increased incidence of bulbous type concha in group I patients compared to group II and III patients. There was no evidence of ipsilateral middle turbinate hypertrophy in any of the three groups; instead, the increasing angle of septal deviation was associated with an increase in the incidence of contralateral middle turbinate hypertrophy, which agrees with the study results of Kucybala I et al., who found that the measurements of the bony and mucosal structure of the contralateral middle turbinate were greater and statistically significant. [26].

This perspective and observational study were conducted to evaluate the septal angle and its effect on the lateral wall of the nasal cavity by C.T. scan, thus highlighting the ancillary pathologies which can lead to an increase in the success rate of surgical procedures. Hence, CT scan PNS is recommended in patients with nasal obstruction to assess the severity of the nasal septal deviation, its impact on the lateral nasal wall and paranasal sinuses, which may help the surgeons in better management of the patients.

This study brings to various light presentations of DNS implicated in the causation of chronic sinusitis, which will influence the treatment decisions and also reduce the morbidity caused by it. There is a need to educate the general masses about the symptoms of chronic sinusitis and its effect on the quality of life to increase its prevention, diagnosis, treatment, and control. Patients should be made aware of the possible sequelae of it if left untreated.