Clear aligner (CA) therapy has experienced rapid use over the past two decades to treat orthodontic malocclusions. However, evidence on CA material degradation in the oral environment remains limited and often focuses on single brands or isolated material properties. To investigate CA ageing characteristics across different materials and brands and evaluate the chemical, physical, mechanical, and morphological changes following simulated or intraoral ageing. Five databases (PubMed, Web of Science, MEDLINE [Ovid], ProQuest, and Scopus) were searched to 18 March 2026, with no restrictions. Studies assessing CA properties after intraoral use or simulated ageing (thermocycling, cyclic loading, or liquid immersion) were included. Study selection followed PRISMA 2020. RoB was assessed using QUIN for purely in vitro studies, JBI for cohort in vivo studies, and Cochrane RoB 2 for RCTs. Results were synthesised narratively and organised by property domain, as substantial methodological heterogeneity precluded formal meta-analysis. Where protocols were comparable, a simple pooled weighted mean was calculated and presented graphically. Ninety-five studies were included. RoB was low in eight studies, moderate in sixty-two, and high in twenty-five. Chemical composition remained largely stable during ageing, though some brands showed trace elemental release. Physical, mechanical, and morphological properties showed material-dependent deterioration. Pooled discolouration was greatest with coffee (weighted mean ΔE = 70.9), versus tea (ΔE = 18.4) and red wine (ΔE = 11.5), with Invisalign® consistently exceeding the clinically perceptible threshold. Force decay of 40–90
Maxillofacial morphological analysis is essential for orthodontic diagnosis, treatment planning, and outcome evaluation. However, previous two-dimensional or landmark-based studies can hardly comprehensively analyze three-dimensional morphology. Therefore, this study aimed to analyze morphological variations and differences of the mandible and midfacial skeleton across different sagittal skeletal patterns and sexes using three-dimensional geometric morphometrics, while also providing novel perspectives and methodologies for morphological analysis in orthodontics. The midfacial skeleton and mandible were analyzed separately. Three-dimensional dense templates were first constructed and template registration was validated. Through template registration, all segmented skeleton images (n = 186) obtained a homologous configuration with tens of thousands of quasi-landmarks. After generalized Procrustes analysis, principal component analysis (PCA) was conducted to examine shape variations. The average skeletal shapes were calculated and compared according to sagittal skeletal pattern and sex. Partial least squares regression (PLSR) was used to evaluate the independent effects of ANB angle and sex on skeletal shape. PCA revealed the principal patterns of shape variations. The first principal component (PC1) of the mandible primarily showed variation in sagittal length and inter-ramal width (explaining 31.80
The maturity of the mid-palatal suture (MPS) could largely determine the necessity of more invasive interventions for correcting transverse maxillary deficiency. CBCT, the most commonly used method for assessing MPS maturity, is not routinely available and exposes patients to higher levels of ionizing radiation than a cephalogram. Given the substantial number of morphological features contained in a cephalogram, this study aimed to estimate CBCT-defined MPS maturity using an entire cephalogram alone via deep learning (DL) algorithms. A total of 543 paired CBCT and cephalogram files available from two distinct hospital settings formed the internal and external datasets. Data augmentation and five-fold cross-validation strategies were applied. Six ResNet-based DL algorithms were initiated via transfer learning. The AdamW optimizer and an early-stopping strategy were employed during training. The models were subsequently tested on the held-out external dataset. The Grad-CAM technique was applied to offer insights into the models’ decision-making process. All algorithms exhibited promising classification performance, with area under the curve (AUC) values ranging from 0.91 to 0.97. The models with the TKSGA module demonstrated better discriminative ability, calibration, and clinical usefulness than their baseline counterparts. Models integrated with the TKSGA module exhibited an interpretable decision pattern. The heatmaps revealed that morphological characteristics of patients’ dentition, cervical vertebrae, and nasopharyngeal airway were primary areas of interest for the DL models. When CBCT imaging is unavailable or not justified, a lateral cephalogram coupled with advanced DL algorithms, could be considered as a supplementary tool to inform palatal expander selection.
CBCT is increasingly used to assess alveolar bone in orthodontic patients; however, reliability and agreement for detecting changes in follow-up assessments remain uncertain. This study evaluated the reliability and agreement of linear marginal alveolar bone level measurements, and agreement in detecting fenestrations in CBCT volumes acquired from different units before and after active orthodontic treatment in adolescents, using a multiplanar reconstruction-based measurement protocol for follow-up studies. CBCT volumes (n = 96) from 48 adolescents (mean age 14.4 years) enrolled in a randomised controlled trial on fixed-appliance treatment for crowding were acquired at baseline and posttreatment using five distinct CBCT units after objective image-quality testing. Buccal and lingual bone levels at the central incisors, canines, and second premolars were measured from the cementoenamel junction to the alveolar crest according to a predefined protocol. Three independent raters performed linear measurements, two assessed fenestrations greater than 2.2 mm, and one repeated all measurements. Reliability was evaluated using intraclass correlation coefficients. Agreement for the bone level measurements was assessed using Dahlberg’s formula and visualised with Bland–Altman plots. Minimal detectable change was calculated per site, and percentage agreement was used for fenestration detection. Intrarater reliability ranged from moderate to excellent at both time points. Dahlberg’s random errors ranged from 0.19 to 0.71 mm at baseline, and 0.19 to 1.07 mm posttreatment. Interrater reliability ranged from poor to good, with random errors ranging from 0.23 to 2.54 mm. Bland–Altman plots revealed minor systematic bias for the intrarater measurements. Minimal detectable changes demonstrated the ability to detect clinically relevant alveolar bone changes. Agreement for fenestration detection was high (intrarater ≥ 81
Abstract Background Precise orthodontic pre-surgical decompensation is a critical prerequisite for optimal outcomes in orthognathic surgery. However, the relative effectiveness of completely customized lingual appliances (CCLAs) versus prefabricated vestibular multibracket appliances (PVMAs) remains insufficiently established. This study compared the decompensation efficiency, treatment quality, and overall clinical performance of these two appliances. Methodology The study included 60 consecutive patients who underwent orthodontic-orthognathic surgery: 30 with CCLA and 30 with PVMA. To ensure quality, the digital ABO CRE for each scanned model was evaluated using OnyxCeph3™ diagnostic software, and the efficiency of each appliance was recorded in the respective patient files. Both groups underwent the same evaluation protocol involving initial, intermediate (pre-surgery) and final casts. An additional set-up model was included for the CCLA group only. Results Both groups exhibited comparable baseline scores (mean difference 5.83; 95% CI 1.69 to 9.98). CCLAs demonstrated lower ABO scores than the PVMA group after the decompensation phase (mean difference − 9.23; 95% CI -13.38 to -5.09) and in the final assessment (mean difference − 9.30; 95% CI − 13.44 to -5.16). The largest differences between groups were observed for the alignment criteria in both jaws at the intermediate and final assessments, as well as for all intermaxillary criteria. Treatment efficiency particularly during the decompensation phase, was significantly improved in the CCLA group. Conclusion CCLAs demonstrated superior efficiency and higher treatment quality compared with PVMAs in patients undergoing combined orthodontic–orthognathic therapy. The use of CCLAs in combination with orthognathic surgery appears to represent a high-quality treatment approach for correcting pronounced skeletal discrepancies and may serve as a reliable alternative to PVMA in appropriately selected patients.
This retrospective comparative cohort study aimed to evaluate the efficiency of maxillary anterior tooth retraction using clear aligners in patients with stable periodontitis compared to periodontally healthy individuals, addressing clinical concerns regarding the efficacy of aligner therapy in this population. This retrospective study included 33 patients with stable periodontitis (SP) and 33 periodontally healthy (PH) individuals who underwent clear aligner treatment. Pre-treatment virtual setups and post-treatment actual models were superimposed in three dimensions using Geomagic Wrap 2021 software. Anterior tooth retraction efficiency was calculated as (actual tooth movement / predicted tooth movement) × 100
This study aimed to clarify the involvement of the root formation stage and apical foramen diameter (AFD) of adjacent teeth in the occurrence of external root resorption (ERR) associated with impacted maxillary canines (IMCs), and to identify novel risk indicators for more accurate clinical prediction. Forty patients with IMCs (58 canines) who underwent cone-beam computed tomography (CBCT) between May 2017 and October 2022 were retrospectively analyzed. The developmental status was assessed using the root formation stage and AFD of the central incisor (U1), lateral incisor (U2), and first premolar (U4). Additionally, spatial factors, including inter-root distance and the 3D position of the IMC, were evaluated in relation to ERR. ERR was detected in 72.5
Abstract Background Superelastic Nickel Titanium (NiTi) exhibits nonlinear and path-dependent behavior that complicates accurate simulation of orthodontic appliances. Standard iterative finite element (FE) formulations often fail to maintain realistic stress evolution during simulations, leading to non-physiologic force predictions. This study introduced an Element-Iteration-Specific (EIS) material model implemented within the FE framework to incorporate the behavior of superelastic NiTi alloy into an iterative simulation, aiming to investigate the biomechanics of a molar uprighting spring and estimate the clinical treatment duration. Methods A two-dimensional (2D) model was constructed representing a 30° mesially tilted mandibular second molar uprighted using a prefabricated superelastic NiTi spring. At each iteration, the EIS algorithm redefines the element specific material parameters of the spring according to the stress–strain state inherited from the preceding iteration, thereby preserving the continuity of its behavior and enabling realistic stress evolution and load transfer between the wire, brackets, and teeth. Results The simulation achieved 23.3° of molar uprighting with 3.0 mm of tangential distal and 2.4 mm of normal extrusive displacements, over an equivalent of 14-week clinical duration. The NiTi spring generated an initial 12.4 N·mm (~ 1265 g·mm) counter-clockwise moment and 0.9 N normal extrusive force. The mean PDL stress remained physiologic, decreasing from 20.3 KPa at wire activation to 13.3 KPa at the end of the simulation. The model successfully tracked the spatial and temporal evolution of the superelastic NiTi’s stress-induced martensitic transformation during activation and uprighting. Conclusions The EIS framework effectively reproduced the nonlinear and history-dependent response of superelastic NiTi, offering clinically representative predictions and establishing a validated computational foundation for optimizing NiTi-based orthodontic appliances and improving treatment outcomes.
BackgroundOrthodontic tooth movement (OTM) is a complex process involving periodontal tissue remodeling, and safe strategies to accelerate OTM remain a research focus. DMXAA (Vadimezan), a non-toxic immune-modulating drug with established clinical trial data, stimulates the secretion of pro-inflammatory cytokines potentially relevant to OTM, which involves immune-mediated bone remodeling.MethodologyA murine OTM model was established in C57BL/6 mice, receiving local subperiosteal injections of DMXAA. Tooth movement distance, bone volume fraction, and osteoclast parameters were quantified via Micro-CT and histology. The mechanism was dissected using RNA-sequencing of bone marrow-derived macrophages (BMDMs), sEV proteomics, and functional osteoclastogenesis assays. Macrophage depletion and Rab13 knockdown models were employed to verify specificity.ResultsLocal DMXAA administration significantly enhance orthodontic tooth movement and rate in mice under orthodontic force application, accompanied by reduced alveolar bone volume and increased osteoclast numbers on the compressive force side. DMXAA induced macrophage accumulation at the force-applied site, polarizing them toward M1-like pro-inflammatory phenotypes characterized by high secretion of CCL5 and CXCL10. Furthermore, small extracellular vesicles derived from DMXAA-treated macrophages, which were enriched with Rab13 protein, contributed to osteoclast fusion and maturation, thereby accelerating OTM.ConclusionsDMXAA accelerates OTM through a dual mechanism: chemokine-driven osteoclast differentiation and sEV-Rab13-mediated osteoclast fusion. These findings highlight the Rab13-sEV axis as a novel therapeutic target for modulating the periodontal microenvironment and enhancing orthodontic efficiency. Our results elucidated a novel mechanism by which DMXAA accelerated orthodontic tooth movement and suggested it as a potential therapeutic agent to optimize orthodontic treatment.
Abstract Objectives To evaluate the accuracy of maxillary canine and anchorage tooth movement in first premolar extraction cases at final canine retraction, using In-house clear aligners (IHCA), by comparing the palatal power arm (PA) to control (C). Methods and Design A single-center randomized controlled trial with a split-mouth design was used. Setting : University. Participants and interventions : Eighteen adults requiring extraction of maxillary first premolars were recruited and received multi-stage IHCA treatment. Main outcome measure: Outcomes include 3 linear (mesio-distal, bucco-lingual, extrusion-intrusion) and 3 angular (tipping, rotation, torque) measurements. The primary outcome was canine distalization. Sequence generation: Patients were assigned to the PA and control sides using sequence-based randomization (Research-Randomizer website). Allocation concealment and blinding were not feasible. Pretreatment and canine final aligner virtual and actual digital models were superimposed using the 3D GOM-Inspect-Suite software to assess 6 types of tooth movement. Equivalence testing with Holm–Bonferroni correction was used to compare mean differences and 90% confidence intervals (CI) between PA and control sides for maxillary canines and anchorage teeth. Results For canine linear movements, the mean differences ranged from −0.19 to 0.09 mm, with corresponding 90% confidence intervals entirely within the predefined equivalence margins of ± 0.5 mm, indicating practical equivalence. In contrast, canine rotation was not equivalent, with a mean difference of 5.22° and a 90% CI of (1.48, 8.95), which exceeded the predefined equivalence bounds of ± 1.5°. Similarly, canine distal crown tipping failed to demonstrate equivalence, with a mean difference of 1.67° and a 90% CI of (− 0.44, 3.78). For anchorage movements, most linear outcomes met the equivalence criteria, except for premolar mesialization and molar buccalization, whereas angular outcomes generally did not, as their confidence intervals were not fully contained within the equivalence region. These findings suggest loss of anchorage on both sides, characterized by mesial crown tipping and relative intrusion, indicating that the PA may not significantly preserve anchorage. Conclusions Linear movements were equivalent between the PA and control, whereas canine angular movements did not demonstrate equivalence. Potential benefit of PA in angulation and rotation control should be interpreted with caution. These findings may have limited generalizability, especially to commercial aligners. Trial Registration Current Controlled Trials ISRCTN 14020146 of the International Standard Randomized Controlled Trial.
Three-dimensional (3D) printing enables customized orthodontic aligners and retainers, but concerns persist regarding the biocompatibility of printable resins. Although ISO 10993-5 and ISO 10993-12 provide guidance for in vitro cytotoxicity testing and sample extraction, substantial flexibility in reporting and execution may hinder comparability across studies. To map how in vitro cytotoxicity testing is performed for materials used to 3D-print orthodontic aligners/retainers and to identify variation and reporting gaps in key ISO 10993-5/-12 testing domains. Following PRISMA-ScR, Ovid MEDLINE, Embase, and Web of Science were searched from database inception to 9 April 2025. Peer-reviewed studies assessing in vitro cytotoxicity of 3D-printed aligners/retainers (and closely related intraoral appliances where relevant) were included. Data were charted across extraction protocols (ISO 10993-12-related), cell exposure parameters, and cytotoxicity assays (ISO 10993-5-related). Twenty-five studies published between 2020 and 2025 were included. Seventeen studies (17/25, 68
Abstract Background The present study was conducted to quantify and compare the geometric accuracy and force application of thermoformed aligners (TFA) and direct-printed aligners (DPA) during mesial and distal rotation of a central upper incisor with a defined activation of 2°. Methodology A 3D-printed model with a mounted central incisor was used to simulate 2° of rotational movement. Forces were recorded in three axes (Fx, Fy, Fz) over 60 minutes using a multi-axis force sensor. Three aligner types (thermoformed with straight trimline: TFAS, direct printed with straight trimline: DPAS, direct printed aligner with garlanded trimline: DPAG) were tested (n = 10 each). Vertical, transverse, and sagittal force components and their decrease were analyzed, and thickness measurements were taken. Results Significant differences in resulting forces were observed between TFA, DPAS, and DPAG during both mesial and distal rotation. TFA generated significantly higher sagittal forces during mesial rotation (1.40 (0.30) N) compared to DPAS (-0.04 (0.05) N) and DPAG (0.11 (0.03) N; p < 0.001). Similar findings were observed for distal rotation (TFA 0.86 (0.16) N; DPAS -0.07 (0.06) N; DPAG 0.10 (0.09) N; p < 0.001). Transverse forces were generally lower, with only selected intergroup differences reaching significance. Time-resolved analysis revealed a pronounced initial force peak followed by continuous decay for TFA, while both DPA designs showed a gradual force increase with plateau formation. TFA showed the most pronounced material loss, whereas directly printed aligners most closely matched the planned thickness. In mesial rotation, significant group differences were found for facial (TFA: 0.42 (0.01) mm; DPAS: 0.71 (0.15) mm; DPAG: 0.63 (0.06) mm), incisal (0.60 (0.02) mm vs. 0.76 (0.11) mm vs. 0.65 (0.06) mm) and palatal surfaces (0.63 (0.01) mm vs. 0.94 (0.17) mm vs. 0.80 (0.06) mm; all p < 0.001). A comparable thickness pattern was observed for distal rotation. Conclusion The results highlight the improved geometric accuracy and underscore the potential of 3D-printed aligners to improve force control and warrant further clinical investigation.
Adenotonsillar hypertrophy (ATH) is a major cause of upper airway obstruction and is associated with specific craniofacial characteristics. However, the craniofacial morphology of children with ATH is controversial. This study aimed to clarify these discrepancies by investigating the association between the adenoid-to-tonsil (A/T) size ratio and craniofacial characteristics in children with ATH, and examining whether age modifies these associations. Children aged 6–10 years were recruited and classified into ATH or no hypertrophy (NH) groups based on lateral cephalograms. For children with ATH, the relative size of the adenoids and tonsils was quantified using the A/T length ratio measured on lateral cephalograms. Based on the median A/T ratio, the ATH group was further divided into two equal-sized groups: a tonsil-dominant (TD) and an adenoid-dominant (AD) group. Craniofacial differences between groups were evaluated. In addition, associations between the A/T ratio and craniofacial morphology were assessed in the ATH cohort. We further examined whether age (6–8 vs. 8–10 years) acted as a moderator of these associations using interaction analyses. A total of 563 children (207 AD, 207 TD, and 149 NH) were included. TD group exhibited greater SNB (B = 0.65, p = 0.028) and Go-Me (B = 0.69, p = 0.038), along with smaller Ar-Go-Me (B = − 0.98, p = 0.029) and Wits (B = − 0.68, p = 0.026) than AD group. In addition, the A/T ratio was positively associated with SGn/FH (B = 0.74, p = 0.048). Moreover, interactions between age and the A/T ratio were observed for MP-SN (B = 2.45, p = 0.044) and Ar-Go-Me (B = 2.86, p = 0.045), and Go-Me (B = − 2.12, p = 0.013). The relative size of the adenoids and tonsils may be associated with craniofacial morphology in children with ATH, with lower A/T ratios tending to be associated with mandibular protrusion and overgrowth, whereas higher ratios appearing to be associated with clockwise mandibular rotation. Notably, age may modify these associations, suggesting the potential importance of timely airway evaluation and management in orthodontic practice.
Orthodontically induced root resorption (OIRR) is a frequent and often irreversible complication of orthodontic treatment, characterized by the pathological loss of hard root tissue under sustained mechanical loading. The risk and severity of OIRR reflect the interplay between mechanical variables (force magnitude, direction, and duration) and patient-specific biological susceptibility. Osteoclasts and osteoclast-like cells on the root surface are the principal effectors of pathological root loss and act in concert with periodontal ligament cells, cementoblasts, osteocytes, and immune populations to generate a local pro-resorptive microenvironment. Mechanical signals are transduced into biochemical cues that engage canonical osteoclastogenesis pathways (RANK/RANKL/osteoprotegerin, MAPK, nuclear factor-κB), and modulatory processes including epigenetic regulation, autophagy/apoptosis balance, reactive oxygen species dynamics, and extracellular matrix remodeling. Systemic factors (hormonal and metabolic status and genetic predisposition) further modify individual susceptibility and therapeutic responses. This review synthesizes current knowledge on the molecular and cellular cascades linking orthodontic force to osteoclastic activation and root resorption and examines how intercellular communication shapes spatial and temporal patterns of tissue breakdown. We critically appraise emerging diagnostics for the early detection of root resorption and evaluate translational therapeutic strategies, including the local delivery of osteoclast inhibitors and biomaterial-based carriers for gene- and cell-based approaches. These strategies aim to selectively suppress pathological root resorption while preserving the alveolar bone remodeling necessary for efficient tooth movement. Taken together, this review discusses the key cellular and molecular regulatory networks involved in OIRR with osteoclasts as the central focus, and outlines future directions, including multi-omics approaches to resolve cellular subpopulation dynamics and the development of local delivery systems targeting osteoclasts.
The increasing use of clear aligners for anterior retraction following first premolar extraction has highlighted undesirable movements of posterior teeth, impeding efficacy and predictability. Although the anchorage preparation of posterior teeth has been proposed to counteract this effect, the optimal methods and extent remain undefined. Effective anchorage preparation strategies to mitigate undesirable movements of posterior teeth during anterior en masse retraction were investigated in this study. A finite element study based on a maxillary first premolar extraction model was conducted to examine posterior tooth movement with different anchorage preparation methods: (1) without any anchorage preparation (control); (2) proactive anchorage preparation (PAP), where 1°, 2°, and 4° distal tipping of posterior teeth were set prior to anterior tooth retraction; and (3) synchronous anchorage preparation (SAP), where 1°, 2°, or 4° distal tipping of posterior teeth was processed with anterior tooth retraction. Compared with the control group, the PAP group exhibited a similar tooth displacement pattern (P > 0.1). SAP effectively controlled mesial tipping when applied at 1.245° for U5, 1.386° for U6, and 2.706° for U7, whereas the optimal resistance to mesial movement required 1.258° (U5), 2.148° (U6), and 2.976° (U7) of SAP, respectively. A 1.25° SAP for U6 successfully prevented lingual torque. However, mesial rotation of the posterior teeth, vertical displacement, torque, and transverse displacement of U5 and U7 remained difficult to control despite SAP adjustments. Compared with PAP, SAP demonstrated superior effectiveness in controlling mesial tipping and displacement, while PAP showed better performance in managing mesial rotation and transverse movements. For optimal anchorage control during SAP implementation, clinicians should pay particular attention to posterior tooth mesial rotation as well as U7 extrusion and buccal torque development.
To compare the efficacy of sliding mechanics on a 0.020-inch round posterior segment incorporated into a bi-dimensional archwire (BA) versus conventional rectangular-section archwire (CONV) for maxillary canine retraction, rotation, angulation, anchorage loss, overbite change, and external apical root resorption (EARR). Randomized, parallel-group, two-arm clinical trial with 1:1 allocation. Department of Orthodontics, University of Damascus; recruitment and treatment July–December 2023. Patients aged 18–25 years with mild–moderate skeletal Class II (ANB + 5° to + 7°) and 5–10 mm overjet scheduled for camouflage treatment with extraction of maxillary first premolars were randomized (N = 38) to: (a) BA—bi-dimensional archwire (0.021 × 0.025″ rectangular in the incisor segment; 0.020″ round in canine/premolar/molar slots) or (b) CONV—conventional rectangular-section retraction mechanics. Primary outcome was monthly maxillary canine retraction rate measured on digitally scanned casts (3D analysis). Secondary outcomes included canine rotation rate, canine angulation change (lateral cephalograms), anchorage loss, overbite change, and EARR (panoramic radiographs). Computer-generated variable block randomization (block sizes 4 and 6) produced by an independent statistician. Sequentially numbered, opaque, sealed envelopes prepared and stored by the independent statistician; opened after eligibility and baseline assessment. Participants and treating clinicians were unblinded; outcome assessors and the study statistician were blinded. Radiographs and digital models were anonymized and allocation was held independently until primary analyses were locked. Thirty-eight participants (19 per arm) completed the study. Observed median retraction rates (T0→TF; T0 = baseline, TF = end of retraction) were BA 1.17 mm/month (IQR 0.20; bootstrap 95
Abstract Background This in-vitro study aimed to evaluate and compare the biomechanical force profiles of thermoformed and direct-printed aligners with different gingival trimlines during facial and palatal translation of a maxillary central incisor. Methods A 3D-printed model with a mounted central incisor was used to simulate 0.25 mm of bodily movement. Forces were recorded in three axes (Fx, Fy, Fz) using a multi-axis force sensor. Three aligner types (thermoformed with straight trimline: TFAS, and direct-printed with either straight: DPAS or garlanded trimline: DPAG) were tested (n = 10 each). Vertical, transverse, and sagittal force components and their decrease were analyzed. Forces were recorded over 60 min to characterize initial force delivery and early stress relaxation under standardized in vitro conditions. Results Thermoformed aligners exhibited the highest sagittal forces during facial movement (Fx − 0.70 N), while DPAG demonstrated significantly lower forces (Fx − 0.25 N; p < .001). During palatal translation, DPAS reached peak forces of 0.57 N, whereas DPAG showed lower, more controlled forces (p < .001). Vertical forces (Fz) were significantly higher in TFAS (− 0.10 N), while DPA remained near zero or slightly extrusive (p < .001). Conclusions In this in vitro model, DPA, particularly DPAG, showed lower sagittal force values and smaller vertical force components. In the first 60 min, DPA showed a pronounced early force decrease. Longer observation periods are required to describe force behavior beyond the initial seating phase.
The application of artificial intelligence (AI) to cephalometry has aroused growing interest due to its potential to optimize clinical workflows and improve efficiency. This study aimed to compare the differences and reproducibility of cephalometric measurements obtained using three methods: manual, WebCeph™ and AngelAligner™. 30 patients were analysed, evaluating 9 measurements generated by the three methods at two different timepoints (T1 and T2). WebCeph™ presented significant differences as compared to the manual method in 7 of the 9 measurements (SNA, SNB, ANB, U1–APg, L1–APg, GoGn–SN, U1–L1), while AngelAligner™ displayed significant differences with the manual method in 4 measurements (SNA, U1–APg, L1–APg and U1–L1). Significant differences were found between the two AI-based systems in 7 of the 9 measurements. Reproducibility was high at all angles with the manual method, except for U1–L1, NLA, and LFH. The ICC was 1 for all measurements for both AI-based systems, indicating optimal reproducibility. When grouping by malocclusions, however, WebCeph™ presented greater differences with the manual method than AngelAligner™. AI-based methods offered greater reproducibility than the manual method, but still require human supervision.
BackgroundThis study aimed to identify prognostic skeletal factors associated with long-term stability following early orthopedic treatment in growing patients with skeletal Class III malocclusion by integrating lateral (LAT) and posteroanterior (PA) cephalometric analyses.Materials and methodsForty-four growing patients with skeletal Class III malocclusion and maxillary retrusion treated with facemask therapy were retrospectively analyzed. Cephalometric records were obtained at pretreatment (T0), posttreatment (T1), and post-growth completion (T2). Patients were classified into favorable growth (FG) and unfavorable growth (UG) groups based on occlusal and skeletal outcomes at T2. Twenty lateral and fourteen posteroanterior cephalometric variables were assessed. Principal factor analysis with Varimax rotation was performed to derive latent skeletal components, which were subsequently evaluated using multiple linear regression to identify predictors of ANB at T2. A classification decision tree was constructed using T0 variables to classify long-term growth outcomes.ResultsFactor analysis yielded five principal variables (PV1-PV5), of which transverse maxillary structure (PV1), maxillomandibular transverse relationship (PV2), and vertical skeletal pattern (PV3) demonstrated significant associations with ANB at T2. A classification decision tree identified the transverse differential between mandibular and maxillary width (Mn. width - Mx. width) as the strongest initial discriminator of long-term prognosis, followed by AB-mandibular plane angle and Sum. The model achieved a classification accuracy of 93.2% in distinguishing favorable and unfavorable growth outcomes.ConclusionsTransverse skeletal proportionality plays a central role in determining the long-term stability of early orthopedic treatment in skeletal Class III malocclusion. Prognostic assessment may benefit from incorporating transverse, sagittal, and vertical skeletal dimensions including measurements from LAT and PA cephalograms, to improve individualized treatment planning and outcome prediction.
To quantify and compare the three-dimensional (3D) deviations of crown and root movements produced by two clear aligner systems based on different materials—SmartTrack (ST) and MasterControl S (MCS)—in first premolar extraction cases using a 3D crown–root registration approach. This retrospective cohort study included 29 patients (58 dental sides) treated with ST (n = 15) or MCS (n = 14). Pretreatment (T0) CBCT images were integrated with T0 and post-treatment (T1) intraoral scans and superimposed using palatal rugae as reference structures. Linear mixed-effects models (LMM) were applied to estimate between-material differences while adjusting for age, sex, and standardized planned movement magnitude. Estimates are reported with 95
