Maxillary sinus volume and dimensions in patients with and without impacted canines: a systematic review and meta-analysis.

OBJECTIVES

To analyze differences in maxillary sinus volume (MSV) and dimensions (length, width, height) in patients with and without impacted canines.

MATERIALS AND

METHODS

Five databases were searched up to August 2025 for studies analyzing MSV and/or dimensions in impacted canine patients using cone-beam computed tomography. Risk of bias was evaluated using the Newcastle-Ottawa Scale (NOS) for cohort and case-control studies. Certainty of evidence was determined using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Meta-analysis was performed in MedCalc.

RESULTS

Five articles met the criteria: three graded "Good" and two "Moderate." The meta-analysis showed a significant MSV difference in unilateral palatally impacted canines (PICs), but not in buccally impacted canines (BICs). No significant maxillary sinus dimension (MSD) differences were observed, though bilateral PICs had fluctuating values. From pre- to post-treatment, MSV tended to increase in PICs. In PICs and BICs, the MS extended more frequently into the incisor/canine regions. A 1000 mm3 decrease in MSV was associated with a 1.7 × increase in PIC odds, and opposite for BICs. Each 1 mm increase in MS height tended to raise PIC odds by 22%.

CONCLUSIONS

MSV tends to be smaller in PICs but not in BICs. Bilateral PICs suggest a reduced MSD, whereas unilateral PICs and BICs do not. MSV tended to increase after the treatment of PICs. PICs may be more common in either smaller or higher sinuses, whereas BICs may occur more frequently in larger sinuses.