Summary Objective To assess upper airway volume changes after rapid maxillary expansion (RME) with three different expanders. Trial design Three-arm parallel randomized clinical trial. Methods Sixty-six patients, 10–16 years old, in permanent dentition, with maxillary transverse deficiency were recruited and assigned with block randomization (1:1:1 ratio) and allocation concealment to three groups of 22 patients each (Hyrax, Hybrid-Hyrax, and Keles keyless expander). The primary outcome (overall upper airway volume change) and secondary outcomes (volume changes in the nasal cavity, nasopharynx, oropharynx, and hypopharynx) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone beam computed tomography. Differences across groups were assessed with crude or adjusted for confounders (gender, age, growth stage, skeletal pattern, baseline airway volume, and amount of expansion) linear regression models. Results Fifty-one patients were analysed (19, 19, and 13 in the Hyrax, Hybrid-Hyrax, and Keles groups). Maxillary expansion resulted in considerable increases in total airway volume in the Hybrid-Hyrax group (+5902.1 mm3) and less in the Hyrax group (+2537.9 mm3) or the Keles group (+3001.4 mm3). However, treatment-induced changes for the primary and all secondary outcomes were of small magnitude and no significant difference was seen among the three expanderes in the total airway volume in either crude or adjusted analyses (P > 0.05 in all instances). Finally, among pre-peak patients (CVM 1–3), the Hybrid-Hyrax expander was associated with significantly greater increases in total airway volume compared to the Hyrax expander (P = 0.02). Conclusions RME resulted in relatively small increases in total upper airway volume and its separate compartments, with mostly no statistically significant differences across the Hyrax, Hybrid-Hyrax, and Keles groups. Limitations Significantly greater attrition was found in the Keles group due to appliance failure. The current trial might possibly be under-powered to detect differences between groups, if such exist. Harms Keles expanders blocked during activations and required substitution for completion of treatment. Protocol The protocol was not published before trial commencement. Registration Australian and New Zealand Clinical Trial Registry (ACTRN12617001136392).

Objective To describe patient and treatment characteristics in West Australian private orthodontic practices. Methods A quantitative retrospective cross-sectional study of patient records from private practices in Western Australia was conducted. Permission was sought to access clinical records of 100 most recently-treated patients at each participating practice. A sample of 3,200 patients (response rate 84%) was collected, representing approximately one-third of practices in Western Australia, and simple descriptive statistics were applied to assess patient and treatment characteristics. Results The majority of patients were female (58.5%), adolescent and had private health insurance (75.6%). The most common patient complaint was crowding (37.6%) and aesthetics (21.3%). Data analysis indicated that 31% of patients were self-referred and a similar proportion did not have a specific complaint. Adult females had a higher interest in aesthetic options. Over half of the patients (56%) received first phase treatment, and non-extraction orthodontics accounted for 61.6% of cases. Full fixed appliances were the most commonly prescribed device (94%). The acceptance rate of orthognathic surgery, when offered, was approximately 30%. Conclusion Clinical data relating to actual patient presentations provide an invaluable insight into the realities of private practice. The eventual course of treatment is often determined by the patient’s tolerances and expectations as much as a clinical recommendation.