Giorgio Oliva

Background: The aim of this prospective longitudinal study was to evaluate three-dimensional facial soft tissue changes following treatment with the Sander Bite Jumping Appliance (BJA) in growing patients with skeletal class II malocclusion. Methods: Seventeen consecutive growing patients (14 males and 3 females; mean age of 11.7 ± 1.1 years) with skeletal class II malocclusion due to mandibular retrusion were treated with the Sander BJA. Three-dimensional facial scans were acquired before treatment (T0) and after completion of active treatment (T1) using a 3dMD stereophotogrammetric system. Twelve angular soft tissue variables were measured after image superimposition using stable facial reference regions. Changes between T0 and T1 were analysed using paired Student’s t-tests (p < 0.05). Results: The facial convexity angle increased significantly from 155.49 ± 4.12° at T0 to 157.21 ± 3.84° at T1, corresponding to a mean change of 1.72° (95% CI: 0.06–3.39; p = 0.044) and a moderate effect size (Cohen’s dz = 0.53). Among the secondary outcomes, significant changes were observed for the SS-N-SL angle (mean change: −1.29°; p = 0.002; dz = −0.89), upper lip position (−1.09°; p = 0.006; dz = −0.77), LS-N-LI angle (−0.69°; p = 0.042; dz = −0.54), and submental angle (+13.86°; p < 0.001; dz = 1.10). No significant changes were observed for the remaining angular measurements. Conclusions: Treatment with the Sander BJA was associated with measurable three-dimensional soft tissue changes predominantly involving the lower facial region. The observed modifications included mainly profile straightening and changes in lip position. Because of the absence of an untreated control group, these findings should be interpreted as treatment-associated soft tissue changes in growing patients.

Background/Objectives: Bite blocks (BBs) are commonly used in clear aligner therapy, yet their effect on masticatory muscle activity is poorly characterised. This study aims to examine the variability in the effects of anterior and posterior BBs on masticatory muscle activity in healthy participants. Methods: Twenty-four healthy adults were included in a crossover design comparing anterior and posterior BBs in removable passive aligners. Surface electromyography measured muscle activity at baseline, 24 h, 48 h and one week. Participants completed psychosocial questionnaires. Response patterns were identified via cluster analysis, and psychosocial differences were assessed with t-tests. Results: Anterior BBs immediately reduced muscle work intensity, with significant inter-individual variability (p = 0.030 at T1; p = 0.047 at T3). In contrast, posterior BBs altered muscle activity without significant variability over time (p > 0.05). Cluster analysis applied to anterior BB revealed two distinct adaptation patterns, which had significantly different Somatosensory Amplification Scale scores (p = 0.040). Conclusions: Within the limitations of the study, in the same participants, wearing passive aligners with anterior bite blocks significantly increased the inter-individual variability of muscular work intensity relative to the no-appliance baseline, whereas passive aligners with posterior bite blocks produced no significant change in variability.

Background/Objectives: The achievement of stable and functional occlusal contacts represents a key objective of orthodontic treatment, particularly in growing patients. Evidence comparing the effectiveness of these two modalities in establishing adequate occlusal contacts in growing patients remains limited. This study aimed to evaluate and compare occlusal contact characteristics following clear aligner therapy (CAT) and fixed orthodontic therapy (FAT). Methods: Twenty-four growing patients (p < 0.05). Statistical difference was also observed in the antero-posterior ratio, with FAT presenting fewer anterior contacts in OCS, NOCS, half-mm, and one-mm measurements (p < 0.05). No significant differences were found between groups in terms of left–right asymmetry or post-treatment single-tooth contacts, except for the second premolar, which exhibited higher contacts in the FAT group (p < 0.05). Conclusions: Fixed orthodontic treatment is more effective than aligners in achieving adequate occlusal contacts, with differences limited to tight contacts and antero-posterior occlusal distribution.