Purpose: To determine the relationship between the dental root indentation and maxillary sinusitis. Methods: We assessed the records of the patients who underwent paranasal sinus computed tomography imaging for suspected sinusitis. Results: We identified a total of 52 patients with a pre-diagnosis of maxillary sinusitis. Dental indentation was detected in 58 of 104 (55.7%) sinuses. Forty six of 58 sinuses (79.3%) with dental indentation had mucosal thickening higher than 2 mm. The difference between the groups was statistically significant (p = 0.007). Conclusion: Dental indentation should be kept in mind as a reason for chronic maxillary sinus inflammation, if an underlying cause cannot be identified.