Lund–Mackay score
The association between accessory ostia of left and right maxillary sinus in the superior meatus and the Lund–Mackay score is shown in Figure 3. The Lund–Mackay score distribution in patients with accessory maxillary sinus ostia in superior meatus was similar to the score distribution in patients without accessory ostia. However, the mean and standard deviation of scores in patients without accessory ostia was approximately two points higher than in patients with accessory ostia in both the left and the right maxillary sinus. There was a statistically significant higher tendency for rhinosinusitis in patients without versus with accessory maxillary sinus ostia in superior meatus (P < 0.001) (Table 3).
DISCUSSION
Chronic rhinosinusitis is a commonly observed condition and has significantly contributed to healthcare consumption and productivity loss, affecting 5%–12% of the global population.13,14 The obstructed drainage and ventilation of paranasal sinuses increase the risk of long-term inflammation.3 Theoretically, the presence of accessory ostia implies disturbance in mucociliary clearance and the mucus circulation of the associated maxillary sinus, which may sustain chronic inflammation.11
We examined the incidence and associations of accessory maxillary sinus ostia in the superior meatus with the presence of chronic rhinosinusitis in a single-centre patient sample using HRCT and 3D simulation images. The results revealed that 41.5% (66) of the patients exhibited accessory maxillary sinus ostia in the superior meatus, irrespective of gender. Several studies conducting cadaver and live endoscopic examinations have reported 0–43% of humans have accessory maxillary ostia.7,15 Mahajan et al. showed that accessory maxillary sinus ostia were observed in 42 out of 200 (21%) half heads,7 and Mladina et al. reported a prevalence of 19.3% for accessory maxillary ostia, with 68% being bilateral.9 Bani-Ata et al. showed that both maxillary and ethmoid sinusitis were significantly associated with male individuals, but the presence of a right or left accessory ostium had no correlation with gender or age.8
Our study showed a significant association between the absence of accessory maxillary sinus ostia in the superior meatus and the Lund–Mackay score. Accessory maxillary sinus ostia present in the superior meatus were associated with less severe chronic sinusitis. Our study is the first to identify and evaluate accessory maxillary sinus ostia in the superior meatus. Previous studies have shown that in patients who have experienced multiple episodes of maxillary sinusitis, the greater frequency of accessory maxillary sinus ostia can be attributed to pathology.1,3,7 Ghosh et al. investigated the correlation between accessory maxillary ostia and chronic sinusitis and recommended that middle meatal antrostomy should include the posterior and anterior fontanelle to reduce mucus circulation.3 If accessory maxillary ostia were present, there was an associated increased incidence of mucus retention cysts by three-fold and the frequency of findings of mucosal thickening and maxillary sinusitis doubled, as shown by Yenigun et al.12 According to Capelli et al., a maxillary mucosa thickness ≥ 2 mm and obstructed natural drainage of maxillary sinus were significantly correlated with chronic rhinosinusitis; however, they found no association between accessory maxillary ostia and chronic rhinosinusitis.16
Genc et al. examined 10 rabbits in New Zealand and found the development of accessory maxillary ostia after inducing sinusitis.17 Accessory ostia can develop when mucosal oedema obstruct main ostia and when chronic sinusitis or other anatomical or pathological factors in the middle meatus disrupt ciliary movement, rupturing membranes in the lateral nasal wall.7 The formation of accessory ostia could sustain sinus mucosa inflammation by enabling the recirculation of mucus between adjacent openings, leading to the chronic recurrence of sinusitis.18 This study showed that patients with accessory maxillary sinus ostia in the superior meatus did not have a higher Lund–Mackay score compared with patients without accessory ostia. A possible inference is that accessory maxillary sinus ostia in the superior meatus are a congenital anatomical variation that do not obstruct the mucociliary clearance of the maxillary sinus. In fact, they may improve the mucus circulation of the maxillary sinus. Our results suggest that patients with accessory maxillary sinus ostia in the superior meatus may have an advantage in not being susceptible to chronic rhinosinusitis. For a surgeon, this information may indicate that patients with this anatomy will have better disease outcomes. However, as accessory maxillary sinus ostia may alternatively be individual anatomic variations of no clinical importance, it is essential to further investigate accessory maxillary sinus ostia in the superior meatus of healthy subjects and in those with chronic maxillary sinusitis.
This study is subject to certain limitations given its retrospective nature and use of radiographic data. The research design does not examine the exact causal relationship between sinusitis and accessory maxillary sinus ostia in the superior meatus. In addition, the study is based on a small sample size and a single-centre design. However, the sample size is large enough to demonstrate statistical significance. While there are several studies that have explored maxillary sinus anatomy and its variations, no clinical research has been conducted on accessory maxillary sinus ostia in the superior meatus. This study is the first to investigate the accessory maxillary sinus ostia in the superior meatus and their incidence in patients with clinical and radiological signs of maxillary sinusitis.