Alveolar Bone Level Changes in Maxillary Expansion Treatments Assessed Through CBCT

Objectives: Objectives: The aim of this study was to determine changes in alveolar bone levels during expansion treatments as assessed through cone-beam computer tomography (CBCT).
Methods: Methods: Sixty-one patients from Edmonton, Canada with maxillary transverse deficiencies were split into three groups. The first group was treated with a bone-anchored expander, the second group was treated with a tooth-borne maxillary expander (Hyrax) and the third group was untreated. CBCTs were obtained from each patient at two time points (initial T₁ and at removal of appliance at 6 month T₂). CBCTs were analyzed using AVIZO software and landmarks were placed on cusp tips, at the cemento-enamel junction and at bone margins of the maxillary premolars and molars and mandibular first premolar and molars. Intra-examiner reliability for landmarks was done by randomly selecting 10 images and measuring each landmark 3 times, 1 week apart. Descriptive statistics, intraclass correlation coefficients (ICC) and One-way ANOVA analysis were used to determine if there were changes to the alveolar bone levels and if these changes were statistically significant between each group.
Results: Results: Landmarks reliability showed an ICC of at least 0.99 with at 95% confidence interval and a mean measurement error of at least 0.2067 mm. Descriptive statistics show that changes in alveolar bone levels was less than 1mm for all three groups and therefore clinically insignificant. Changes between groups were not statistically different (p<0.05) from one another with the exception of 8 distances. However, since the distances were small, they were considered not clinically significant.
Conclusions: Conclusion: Alveolar bone levels changes were similar in maxillary expansion treatments and in the control group. The effects of maxillary expansion treatments on alveolar bone levels are not clinically significant.