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Introduction: Orthodontic mini-implants (MI) are a reliable alternative to provide temporary orthodontic anchorage. Prior to miniscrew insertion, the best approach would be to evaluate each possible insertion site and measure the cortical bone thickness, and verify whether it would provide adequate primary stability. Objective: This study aimed to evaluate the difference in cortical bone thickness in areas of mini-implants insertion in patients of different ages, by means of cone beam computed tomography (CBCT). Methods: The sample of this retrospective study was composed of 123 CBCT scans, which were used to measure cortical bone thickness in the buccal and palatal inter-radicular space in the mesial region of the first permanent molars. These measures were compared by using the Student’s t-test, ANOVA/Tukey tests, and Linear regression between male and female subjects, from 12 to 30 years old. Results: No significant difference was found in cortical bone thickness between sex, race and sagittal facial patterns. Significantly higher measurement values were observed in patients older than 12 years of age at all sites evaluated. The coefficient β at the adjusted linear regression analysis showed that at each increment in age, mean cortical thickness values increased by 0.06mm in the mandible, 0.03mm in the buccal region and 0.02mm in the palatal region of the maxilla. Conclusions: The increase in cortical bone thickness was positively associated with age; that is, the more advanced the patient’s age was, the less chance there was of failure due to primary stability.

ObjectiveTo evaluate the effects of rapid maxillary expansion (RME) on Sleep Disturbance Scale for Children (SDSC) with maxillary atresia.Materials and MethodsThe sample consisted of 27 paediatric patients evaluated through a Brazilian version of the SDSC, answered by their guardians at the following experimental time points: T0 (before installing the Hyrax expander), T1 (on the day of expander stabilization), T2 (3 months after expander stabilization), T3 (immediately after expander removal, following 6 months of retention), and T4 (3 months post‐retention). Multilevel Poisson analysis adjusted for repeated measures was performed to compare outcomes across the assessment time points.ResultsThe mean age of patients was 9.1 years (SD = 1.46). The total SDSC scores decreased and were statistically significant from T2 onwards (P < .01), with a decrease of 24% at T4 compared with T1 (IRR 0.76; 95% CI 0.69–0.84). The mean scores at T4 were already lower than the cutoff point for risk of sleep disorders. Regarding the specific domains, there was a significant reduction in sleep breathing disorders, sleep–wake transition disorders, and disorders of excessive somnolence as of T2 (P < .01), T3 (P < .05) and T4 (P < .05), respectively.ConclusionRME in children with maxillary atresia had a positive effect on the reduction of total SDSC scores after 3 months of expander stabilization, sustained over 6 and 9 months and significant reduction in sleep breathing disorders domain, sleep–wake transition disorders domain, and disorders of excessive somnolence domain over time points.