Background: The use of aligner therapy for open bite and deep bite correction has increased in contemporary society. There is no evidence that unify the results present the in literature regarding a real comparison between clinical outcomes and the results predicted by the ClinCheck software 3.0 (Align Technology, Santa Clara, CA, USA). Furthermore, the literature shows conflicting data about the protocols and not all authors compare the programmed movements and the clinical results obtained for the overbite correction. Therefore, the aim of this systematic review is to assess the predictability of ClinCheck in the correction of vertical discrepancies by comparing the planned outcomes with the actual clinical results performed with clear aligners. Methods: The research question focused on the effectiveness of ClinCheck in predicting the actual correction of deep bite AND open bite in adult patients. Five electronic databases (PubMed, Scopus, Embase, Web of Science and Cochrane Library) were investigated, with the following keywords: overbite AND aligners. A quality assessment was performed using the Newcastle-Ottawa scale, while the risk of bias was evaluated using the ROBINS-I tool 2.0. PROSPERO ID: CRD420251078610. Results: Out of a total of 838 records initially screened, seven studies fulfilled the inclusion criteria and were ultimately selected for this systematic review. The analysis focused on assessing the divergence between the overbite correction predicted by ClinCheck and the outcomes observed in clinical practice. Conclusions: ClinCheck demonstrated a predictability of 62.1% for overbite correction in open bite cases and 41.5% in deep bite cases. However, not all studies report the planned tooth movements. Among the studies that addressed this aspect, the majority reported no significant association between the overbite correction predicted during treatment planning and the results ultimately achieved—except for one study, which demonstrated significant accuracy in achieving absolute extrusion in the correction of open bite.

The widespread use of portable electronic devices has increasingly promoted the prolonged maintenance of non-physiological postures, particularly anterior and downward head flexion. Therefore, this study aimed to analyze the condylar and incisor relationship displacement induced by this improper posture. A total of 20 adult subjects (9 F, 11 M; mean age 27 ± 5) were recruited at the Department of Dentistry, Vita-Salute San Raffaele University, Milan, Italy. Mandibular kinematics was recorded using JMA-Optic AG (Zebris Medical GmbH, Isny, Germany). The protocol adopted consisted of three phases: (1) Habitual occlusion with light clenching, (2) Neuromuscular rest position (RP) verified by surface electromyography (sEMG), (3) Anterior head flexion (40–60°) (HF), simulating the posture typically observed during portable digital device use. Millimetric measurements of condylar displacement from RP to HF and incisal plane changes were collected. Data were analyzed descriptively with Microsoft Excel, and inferentially with StatPlus Pro (AnalystSoft, StatPlus: mac Pro, version 8). The right condyle exhibited a mean displacement of 1.9 mm in the downward direction (p < 0.001), while the left condyle showed a downward displacement of 1.5 mm (p < 0.001). No significant difference was observed between the two sides. At the dental level, the lower incisor revealed a mean shift of 1.0 mm superiorly (p < 0.001) and 0.7 mm anteriorly (p < 0.001). The HF determines a significant condylar and incisal plane displacement, and may predispose individuals to TMJ disorders, supporting the hypothesis of an emerging cranio-cervico-mandibular condition linked to prolonged use of high-tech display terminals, here proposed as ED-TMD (Electronic Device-Induced Temporomandibular Disorder).

Background: The widespread use of portable electronic devices may involve prolonged exposure to altered cranio-cervical postures. This study investigated whether participants classified as HT+ and HT− according to a predefined operational classification differed in masticatory muscles recruitment. Methods: This cross-sectional study included 50 healthy adults (30 F, 20 M; mean age, 27 ± 5 years) classified into two operational groups. The HT+ group (n = 25) was defined by the simultaneous presence of portable electronic device use >8 h/day and habitual marked anterior head flexion, whereas the HT− operational group (n = 25) included participants who did not simultaneously meet both criteria. Participants underwent surface electromyography of the masseter and anterior temporalis muscles during maximum voluntary clenching (MVC) in the neutral head posture and during anterior head flexion (approximately target range 40–60°) using the MyoWise device (MyoWise, Via Gran Sasso 18, 20008 Bareggio, Milan, Italy). Percentage Overlapping Coefficients, Asymmetry Index, Activity Index, Torque Index, and Impact were assessed. Between-group comparisons, within-group posture-related changes, and between-group comparisons of change scores (Δ) were performed using parametric or non-parametric tests according to data distribution. The between-group comparison of the Activity Index in the reference posture was predefined as the primary analysis, whereas secondary analyses were adjusted for multiple comparisons using the Benjamini–Hochberg false discovery rate (FDR) procedure. Statistical significance was set at p < 0.05 for the primary analysis and at FDR-adjusted q < 0.05 for secondary analyses. Results: The Activity Index was significantly more negative in HT+ than in HT− participants in both the reference posture (p < 0.001) and during anterior head flexion (p = 0.003; q = 0.032). The Activity Index decreased significantly from the neutral head posture to anterior head flexion in both groups (HT+: q = 0.025; HT−: q = 0.002), whereas the magnitude of this change did not differ significantly between groups (p = 0.101; q = 0.607). No other sEMG outcome remained significant after FDR correction. Conclusions: The HT+ operational group was associated with a distinct temporalis–masseter recruitment pattern in asymptomatic adults. The Activity Index emerged as the sEMG parameter most strongly associated with operational HT classification, indicating that the observed between-group differences primarily involved the relative recruitment balance between the jaw-elevator muscles.

Background: Digital mandibular kinematic analysis complements clinical examination by quantifying movement amplitude, symmetry, coordination, and trajectories. However, device-specific acquisition and processing characteristics may influence the measurements obtained with different jaw-tracking systems. Therefore, this study aimed to assess systematic differences in mandibular kinematic measurements and inter-system agreement among three commercially available digital jaw-tracking systems. Methods: Twenty healthy adults (12 M, 8 F; mean age, 27 ± 5 years) underwent assessment with Zebris JMA-Optic (Amann Girrbach AG, Koblach, Austria), Modjaw (Modjaw SAS, Villeurbanne, France), and Itaka (Itaka Way Med Srl, Marcon, Italy). Maximum mouth opening, protrusion, and bilateral lateral excursions were recorded in at least three valid trials, with the maximum excursion used for analysis. Differences among systems were evaluated using repeated-measures ANOVA with Bonferroni-adjusted post hoc comparisons. Overall inter-system agreement was assessed using the absolute-agreement intraclass correlation coefficient (ICC), while pairwise agreement was further characterized using Bland–Altman analysis. Proportional bias was assessed by linear regression of pairwise differences against their corresponding means. Results: Maximum mouth opening differed significantly among systems (p = 0.047; partial η² = 0.148). Modjaw recorded higher values than Itaka (mean difference, 2.49 mm; adjusted p = 0.038; Cohen’s dz = 0.62). No significant differences were found for right lateral excursion (p = 0.161), left lateral excursion (p = 0.293), or protrusion (p = 0.873). Agreement was moderate for maximum mouth opening (ICC = 0.601), right lateral excursion (ICC = 0.747), and protrusion (ICC = 0.718), but poor for left lateral excursion (ICC = 0.443). Bland–Altman analyses showed movement- and system-pair-specific variability in measurement differences, with no evidence of proportional bias. Conclusions: The three digital jaw-tracking systems showed movement-dependent differences in mandibular kinematic measurements and varying levels of inter-system agreement. These findings indicate that measurements obtained with different systems should be interpreted in the context of the specific movement assessed and the characteristics of the corresponding acquisition and processing workflows. Further studies are needed to determine the clinical relevance of the observed inter-system variability.