Maxillary Sinus Changes in Adolescents Analyzed via Cone-Beam Computed Tomography

Objectives: The purpose of this study was to analyze maxillary sinus changes over time in adolescents, in terms of shape and volume, using cone-beam computed tomography – CBCT reconstructions.
Methods: A total of 274 maxillary sinus in 137 CBCT scans of 57 patients were analyzed. For each patient, there was a time lapse of either 2, 3 or 4 years between examinations. All images were from an available pool of scans of patients from the University of Alberta Orthodontic Clinic. CBCTs were visualized and evaluated using AVIZO®. The outline of the sinuses was landmarked manually in its entirety. 3D models of the air-filled structures were constructed and the shapes and volume of each sinus was evaluated. Ten images of scans not included in the study were analyzed to determine intra-reliability of each the overall shape and volume of each sinus. ANOVA, Bonferroni correction and t-test were used to compare groups.
Results: It was found that 88.3% of the obtained datasets are most similar to another dataset obtained from the same patient showing the method of measurement as being reliable. The changes in shape of the maxillary sinuses were subtle and minimal, at a value of 5.13mm (SD 5.58mm). The changes in volume were substantial from time 1 to time 2 (and to time 3 when applicable); the percentage of change was of 21.3% (SD 23.79%).
Conclusions: Maxillary sinus volume grows considerably over time, while its shape only changes subtly. In adolescents, the sinuses change substantially as a whole and the modifications are significant, as shown by the CBCT images and landmarks.