Short-term dentoalveolar effects of aesthetic lip bumper appliance: A longitudinal cases-series and pilot study.

Background: To investigate the short-term dentoalveolar effects on the mandibular arch of a modified, aesthetic lip bumper (ALBAa). The study sample comprised 23 patients (13 boys and 10 girls, with a mean age of 9.5 ± 1.8 years) in mixed dentition, with no previous orthodontic treatment. For each patient, a scan of the mandibular arch was digitally acquired pre-treatment (T0), and at 3 months (T1), 6 months (T2) and 9 months (T3) post-treatment. Linear intra-arch measurements, Little's irregularity index of the amount of mandibular anterior crowding, and the crown tipping values on all mandibular teeth were measured and compared statistically between time points. ANOVA and subsequent post-hoc tests were performed, considering a p-value of < 0.05 as significant. Results: Linear intra-arch distances and crown tipping values on the mandibular teeth increased between the following time points: T0vsT1, T1vsT2, T0vsT2 and T0vsT3 (p < 0.05), although in the last three months of observation (T2vsT3) they only reached statistical significance at the lower incisors and lower left premolar concerning crown tipping values. There was a statistically significant decrease in anterior crowding throughout the observational period (p < 0.05), and this effect was equally distributed across the different time points investigated. Conclusions: ALBAa therapy led to an increase in both linear intra-arch distances and crown tipping values, with a reduction in Little's index. The distribution of the effects reported across the observational period depended on the mechanism of action (mechanical vs. functional).

Class II treatment of transverse maxillary deficiency with a single bone-borne appliance and hybrid clear aligner approach in an adult patient: A case report.

This case report describes the successful orthodontic treatment of a 22-year-old female patient affected by Class II malocclusion, maxillary skeletal transverse deficiency, ectopic maxillary left lateral incisor, and mild mandibular crowding. Due to her adult skeletal age, a bone-borne appliance was applied in order to obtain both purely skeletal rapid maxillary expansion and bilateral molar distalization. After accurate matching between the pretreatment cone-beam computed tomography scan and digital models, 4 self-drilling miniscrews were inserted palatally using a computer-aided design and computer-aided manufacturing (CAD/CAM) surgical template to guide their correct and safe placement, and a bone-borne appliance was fitted. After this first phase, the hybrid clear aligner approach was used to obtain alignment, levelling, and arch coordination, with the use of a partial lingual fixed appliance on the maxillary incisors.

Analysis of biological and structural factors implicated in the clinical success of orthodontic miniscrews at posterior maxillary interradicular sites.

OBJECTIVE: This study aims to evaluate success factors implicated in clinical orthodontic miniscrew stability after their interradicular placement in maxilla. MATERIALS AND METHODS: Six hundred seventy-six miniscrews were inserted in maxillary interradicular sites in a sample of 276 patients (109 males and 167 females; mean age 19 ± 1.7 years) and immediately loaded. Percentage failure rate was recorded, and the influence of the following factors was investigated: structural (miniscrew length, diameter and body shape), operative (side of insertion site, pilot hole drilling or not) and biological (maximal insertion torque [MIT] and type of gingiva). A chi-square test with Monte Carlo correction was performed to detect the influence of these variables on the failure rate of orthodontic miniscrews. Then both multivariate logistic regression and post hoc analysis were performed, followed by classification and regression tree (CART) analysis. RESULTS: The average success rate was 88%. The principal factors implicated in the failure rate were miniscrew length, MIT values and type of gingiva. Specifically, 8 mm miniscrew length, alveolar mucosa and 5-10 Ncm MIT values were linked to higher failure rates. According to CART, the main variable influencing failure is miniscrew length (≤ 8 mm for higher failure rates). For others, MIT values of 5-10 Ncm are linked to higher failure rates (p < 0.05). CONCLUSION: Orthodontic miniscrews inserted in the maxilla display good success rates. However, clinicians should be discouraged from using miniscrews of length ≤ 8 mm and MIT values < 10 Ncm, even with longer miniscrews. CLINICAL RELEVANCE: Information about factors related to failure rate of miniscrews placed at posterior maxillary interradicular sites is given.