OBJECTIVE:To evaluate publications on mandibular advancement devices through bibliometric and altmetric analysis. METHODS:A search was conducted in the Web of Science Core Collection (WoS-CC) initially in August 2024, with an update in December 2025, including all articles on mandibular advancement devices, with no restrictions on language or publication date. Editorials, abstracts, and conference papers were excluded. Two independent reviewers selected the studies and extracted data on citations, year, journal, study design, type of device, study objective, geographic origin, authors, and keywords. Altmetric analysis was performed using Dimensions. Spearman's correlation tested associations between impact factor, year, and citations, and bibliometric networks were created with VOSviewer. RESULTS:A total of 446 articles were published between 1979-2025. The most cited article received 352 citations, and the American Journal of Orthodontics and Dentofacial Orthopedics published the largest number of studies (n = 174). Clinical trials were the most frequent design (n = 175), mainly addressing skeletal, dental, facial, and esthetic changes (n = 175). The Herbst appliance was the most investigated (n = 129). Germany (n = 52) and Europe (n = 236) led the publications, with Giessen University as the most productive institution (n = 37). The most prolific author was Pancherz H (n = 31). Altmetric analysis revealed relevant mentions on Mendeley and Facebook. CONCLUSION:Europe concentrated the largest scientific output on mandibular advancement devices, particularly the Herbst appliance, in studies focused on skeletal, dental, facial, and esthetic changes.
INTRODUCTION:Mixed dentition analysis is essential for predicting space requirements and guiding early orthodontic decision-making. Moyers analysis is widely used due to its simplicity and clinical applicability, however, manual execution may increase execution time and introduce operator-dependent errors. OBJECTIVE:This study aimed to develop and validate an automated digital tool based on Moyers analysis, to improve efficiency and support orthodontic education. MATERIAL AND METHODS:This cross-sectional study included 20 participants (10 undergraduate and 10 graduate dental students) who performed mixed dentition analysis on a standardized plaster model using the manual method and a software-based method at separate time points. Agreement between methods was evaluated using intraclass correlation coefficients (ICC), Bland-Altman analysis, and linear regression to assess proportional bias. Execution time was recorded and compared using paired t tests. Participant preference was also assessed. RESULTS:Excellent reliability was observed (ICC > 0.95). No statistically significant differences were found between the manual and software-based methods (p > 0.05), and Bland-Altman analysis demonstrated substantial agreement without proportional bias. The software-based method reduced execution time by 38.2% (p < 0.001). All participants preferred the software-based method. CONCLUSION:The software-based method demonstrated agreement comparable to the manual Moyers analysis, while significantly reducing execution time. Its usability and efficiency support its application in orthodontic education and clinical workflow optimization.
OBJECTIVE:This study assessed the characteristics of the 100 most-cited papers on the biopsychosocial impact of malocclusion in school-aged youth. METHODS:The Web of Science Core Collection (WoS-CC) database was searched. Data extracted included title of the paper, year of publication, authorship, number of citations, institution, country, continent, study design, journal and its impact factor, and keywords. A content analysis was performed to extract information on malocclusion diagnosis indices, age group, sample size, biopsychosocial outcomes, and assessment instruments. Bibliometric networks were created using VOSviewer and Power BI software. Descriptive analyses and Poisson regression were conducted (p < 0.05). RESULTS:The 100 most-cited articles were selected from the 1,297 studies, totaling 3,621 citations. Most of the studies were cross-sectional (n=89), with a majority originating from Brazil (n=54). The Angle Orthodontist and the American Journal of Orthodontics and Dentofacial Orthopedics stood out with the highest number of publications and citations (11 articles, 532 and 461 citations, respectively). The authors with the most citations was C.A. Feldens, being the most cited author (n = 256). "Malocclusion" was the most used keyword (n = 39). The most prolific institutions were Universidade Federal de Minas Gerais (12 articles), Universidade Estadual de Campinas (11 articles), and Universidade Federal de Santa Maria (8 articles). CONCLUSION:Cross-sectional studies conducted by Brazilian authors examining the impact of malocclusion on oral health-related quality of life predominated. More diverse study designs, broader geographic representation, and longitudinal approaches are necessary to strengthen the evidence on the biopsychosocial effects of malocclusion.
OBJECTIVE:To investigate the prevalence of tooth agenesis and its association with other developmental dental anomalies in non-syndromic patients. The study also evaluated the applicability of machine learning models to predict the occurrence of agenesis. METHODS:This cross-sectional observational study analyzed 4,990 panoramic radiographs from radiology centers in Uberlândia, Minas Gerais/Brazil. It assessed the presence of tooth agenesis and associated anomalies, such as palatal displacement of canines, distoangulation of lower second premolars, tooth transposition, infraocclusion of deciduous molars, mesioangulation of lower second molars, and supernumerary teeth. The tooth agenesis code (TAC) mapped the patterns of occurrence. Fisher's exact test, Student's t-test, and logistic regression were used to analyze the data (p < 0.05). The machine learning models used included Decision Tree, Random Forest, XGBoost, Support Vector Machine, and Deep Learning. RESULTS:Agenesis was found in 6.1% of patients, with a higher prevalence in females (57.6%) and younger individuals (mean age of 16.8 years). Dental transposition (OR: 19.11; p < 0.001), maxillary canine displacement (OR: 2.08; p < 0.001), and deciduous molar infraocclusion (OR: 147.73; p < 0.001) showed a significant association. The Random Forest model showed the best predictive performance, but with clinical limitations. CONCLUSION:Tooth agenesis is associated with an increased risk of other anomalies, highlighting the importance of early diagnosis and integrated therapeutic approaches.
ABSTRACT Introduction: Class II, division 1 malocclusion is the most common sagittal discrepancy, marked by distal positioning of the lower teeth, upper incisor protrusion, maxillary constriction, and facial profile imbalance. Its multifactorial etiology-skeletal, dental, and functional - results in diverse clinical presentations and treatment approaches. Objective: This article aims to present a series of clinical approaches for the management of classic Class II, division 1 malocclusion, underlining how different treatment modalities -selected according to individual patient characteristics- can lead to effective outcomes. Considerations: Treatment strategies for Class II, division 1 malocclusion include growth modification, headgear therapy, maxillary molar distalization with temporary anchorage devices (TADs), premolar extractions, clear aligner therapy, and orthodontic-surgical approaches for severe skeletal cases. Advances in biomechanics and skeletal anchorage have expanded non-extraction and less invasive options. However, careful case selection remains essential. Diagnosis must assess skeletal, dental, functional, and psychosocial factors, with treatment choices balancing esthetics, biomechanics, stability, and patient cooperation, customized to individual needs
ABSTRACT Introduction: Orthodontic tooth movement (OTM) is regulated by alveolar bone remodeling through the receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) axis. Clear plastic aligners (CPAs), available as thermoformed and direct-printed variants, differ in force delivery and material properties, influencing biomarker responses. Objective: This prospective pilot randomized study compared salivary and gingival crevicular fluid (GCF) levels of RANKL and OPG during treatment with thermoformed and direct-printed aligners, and evaluated correlations between saliva and GCF. Material and Methods: Eight healthy adults (18-40 years) requiring orthodontic treatment were randomly assigned to thermoformed or direct-printed aligners. GCF and unstimulated saliva were collected at baseline and at 1, 2, 3, 4, and 6 weeks. RANKL and OPG were quantified using ELISA, and data were analyzed with SPSS v21.0 (IBM, USA). Results: Thermoformed aligners exhibited a peak in GCF RANKL at 3 weeks, followed by a decline at 6 weeks. Direct-printed aligners showed a gradual reduction, with significantly lower RANKL at 4 and 6 weeks (p < 0.05). OPG levels were consistently higher in the direct-printed group across all time points in saliva and GCF (p < 0.05). Salivary OPG strongly correlated with GCF OPG at baseline, 3, and 6 weeks, while RANKL correlations were higher during later treatment phases. Conclusion: Aligner types elicited biomarker responses consistent with bone remodeling. Direct-printed aligners demonstrated a trend toward a more stable, OPG-dominant biological response. These findings should be interpreted cautiously, due to the pilot nature of the study. Saliva correlated with GCF, supporting its use as a non-invasive biomarker source. Larger longitudinal studies are warranted.
ABSTRACT Introduction: The growing adoption of aligners contrasts with the lack of clear foundation in the literature regarding their activation methods. Studies often focus on effectiveness or estimated forces, lacking rational standardization and frequently presenting results that conflict with clinical practice. Objective: This article analyzes the theoretical inconsistencies about how aligners work and proposes an alternative analytical approach to understand the force system they generate. It also explores how the use of attachments can modulate the direction of these forces to enable specific orthodontic movements. Methods: To assess aligner activation, a two-dimensional model representing a maxillary central incisor was developed. This model, using palatal tipping and extrusion movements, enabled analysis of the aligner’s activation mechanism and the influence of attachments on force redistribution. Results: The analysis showed consistency with previous studies, providing a rational explanation for aligner activation in these movements. Attachments proved essential in modifying force distribution, enabling displacements beyond the buccolingual axis. Conclusions: In their current configuration, aligners predominantly generate normal buccal and lingual compressive forces through flexion, lacking intrinsic capacity to produce orthodontically useful forces such as traction, torsion, or shearing in the buccal and lingual planes. However, the strategic use of attachments allows interception of the aligner’s deactivation and redirection of a fraction of the original forces, making other types of orthodontic movements feasible. This highlights the need for a rigorous biomechanical approach for each necessary movement for each tooth, to optimize aligner efficiency in clinical treatments.
ABSTRACT Objective: To examine the accuracy of adolescents’ self-recognition based on their facial profiles and determine the influence of sociodemographic characteristics and perceived well-being and self-esteem on this ability. Methods: A cross-sectional study was conducted with 158 adolescents (10-19 years old) who were either students or patients at the School of Dentistry, Federal University of Minas Gerais, Brazil. The facial profile of adolescent was photographed and included on a template of ten profile photographs, being nine standardized photographs and one was the participant’s own photograph. The adolescent was asked to recognize her/his own profile among these ten photographs. Perceived self-esteem was measured by the Brazilian version of the Rosenberg Self-Esteem Scale. A questionnaire addressed sociodemographic characteristics, with one item assessing whether the adolescent’s wellbeing was affected by her/his oral condition. Adjusted Poisson regression was performed (p<0.05). Results: Adolescents 17 to 19 years of age were 1.78 times more likely to recognize their own facial profile, compared to adolescents 10 to 13 years of age (95%CI:1.31-2.43). Adolescents’ perception that their general wellbeing was impacted by their oral conditions were less likely to recognize their own facial profile compared to those whose did not perceive this impact (PR = 0.72; 95% CI: 0.55-0.94). Conclusions: Older adolescents were more likely to recognize their own facial profile, while those reporting that oral health concerns affected their well-being showed poorer recognition ability. Engaging adolescents in decisions and considering their perceptions enhances satisfaction, adherence, and treatment outcomes.
ABSTRACT Objective: This study aimed to translate, culturally adapt, and estimate the psychometric properties of the Catastrophizing Questionnaire (CQ) for use in Portuguese among orthodontic patients. Methods: The translation process followed international guidelines, including forward and backward translation. Confirmatory factor analysis (CFA) was conducted to assess factorial validity, using indices such as the Comparative Fit Index (CFI), Tucker-Lewis Index (TLI), Root Mean Square Error of Approximation (RMSEA), and Standardized Root Mean Square Residual (SRMR). Convergent validity [Average Variance Extracted (AVE)] and reliability were estimated. Results: A total of 334 Brazilian orthodontic patients (74.6% female, mean age = 30.6 years, standard deviation 12.4) participated in the study. The factor model of the Portuguese version of CQ presented an adequate fit to the data (CFA: CFI = 0.95, TLI = 0.94, RMSEA = 0.07, and SRMR = 0.06). Reliability was acceptable (α and ω ≥ 0.93). Although the AVE was slightly below the recommended threshold (AVE = 0.41), the overall model fit and internal consistency supported the adequacy of convergent validity. Conclusion: The Portuguese CQ showed adequate psychometric properties for assessing catastrophizing in Brazilian adult orthodontic patients. As a pain-independent measure, it enables the early identification of catastrophizing tendencies before appliance placement, supporting a patient-centered approach. By helping clinicians recognize individual psychosocial vulnerabilities, the CQ can guide tailored communication and management strategies aimed at improving the overall treatment experience.
ABSTRACT Objective: This study investigated the perception of smile attractiveness and age estimation based on different proportions of maxillary and mandibular incisor exposure, combined with changes in lower lip vermilion height. Methods: Smile photographs were digitally modified to create images with varying proportions of incisor exposure (100%, 80%, 60%, 40%, and 20% maxillary incisor exposure) and reduced or unaltered lower lip vermilion height. A total of 162 evaluators, including orthodontists, dentists, and laypersons, rated attractiveness using a 10-point visual analog scale and estimated the apparent age range (<30, 30-50, >50). Results: Maxillary incisor exposure significantly affected smile attractiveness, with higher exposure levels (100% and 80%) receiving higher attractiveness scores across all evaluator groups (p < 0.05). Reduction in lower lip vermilion height did not result in statistically significant differences in attractiveness ratings or age estimation (p > 0.05). Orthodontists assigned significantly lower attractiveness scores than dentists and laypersons (p < 0.05). Increased mandibular incisor exposure was significantly associated with the perception of an older apparent age (p < 0.05). Older laypersons demonstrated greater tolerance toward smiles with increased mandibular incisor exposure (p < 0.05). Conclusions: These findings suggest that the proportion of maxillary and mandibular incisor exposure plays a significant role in the perception of smile attractiveness and age estimation. Furthermore, they highlight the importance of considering individual preferences in dental treatment planning. The results of this study have direct implications for clinical practice in Orthodontics and Esthetic Dentistry, providing valuable guidance for treatment planning and patient communication.
ABSTRACT Objective: To evaluate the impact of orthodontic treatment on perceived smile attractiveness and hiring decisions in a Brazilian adult population. Methods: A cross-sectional observational study was conducted with 288 adult participants recruited via an online survey. Three clinical cases were selected, and standardized pre- and post-treatment smile photographs were shown in randomized order. Participants rated attractiveness on a 0-100 Visual Analog Scale (VAS) and indicated hiring intention (“yes,” “no,” or “can’t tell”). Descriptive statistics, Mann-Whitney U tests, chi-square tests, and logistic mixed-effects regression models were used for data analysis. Results: Post-treatment images showed significantly higher attractiveness ratings, compared with pre-treatment images (mean VAS: 54.2 vs. 36.4; p < 0.001). Hiring likelihood also increased after orthodontic treatment (44.0% vs. 27.9%; p < 0.001). Affirmative hiring decisions were consistently associated with higher attractiveness scores. In multivariable analysis, attractiveness was a significant independent predictor of hiring intention, while the interaction between VAS and treatment status was not significant (p = 0.201). Individual-level assessments demonstrated that many participants initially classified as non-hireable were reevaluated positively after treatment. Conclusions: Orthodontic treatment significantly improved smile attractiveness and increased hiring likelihood. Dental alignment alone was sufficient to shift social judgments, although overall facial esthetics also contributed. The identified attractiveness threshold marked the point at which orthodontic improvement began to influence employability perceptions. These findings highlight the psychosocial relevance of orthodontics beyond functional benefits.
ABSTRACT Introduction: Although AI-assisted cephalometric applications are widely used, most validation studies involve adult radiographs. Pediatric craniofacial landmarks show greater variability due to growth, which may influence automated landmark accuracy. Therefore, pediatric-specific validation of AI-based smartphone cephalometry is essential. Objective: This study evaluated the reliability, reproducibility, and time-efficiency of an AI-assisted smartphone application (WebCeph) compared with manual cephalometric tracing in children. Methods: A retrospective cross-sectional study was conducted on 51 lateral cephalograms of children aged 7-12 years. Manual tracings were performed by a calibrated examiner, and digital tracings were obtained using the WebCeph Android application. Linear and angular measurements were recorded for both methods. Intra-examiner reliability was assessed using intraclass correlation coefficients (ICC). Agreement between methods was evaluated using paired t-tests and Cohen’s d. Tracing time was documented, and normality was confirmed using the Shapiro-Wilk test. Results: Both methods demonstrated high reliability. Most parameters showed no significant differences, although a few (SNA, ANB, L1-MP) showed statistically significant but clinically negligible discrepancies. ICC values indicated excellent agreement. WebCeph significantly reduced analysis time (9.4 ± 1.82 minutes), compared with manual tracing (19.4 ± 2.65 minutes). Conclusion: The WebCeph AI-assisted smartphone application provides reliable and clinically comparable cephalometric measurements to manual tracing in pediatric patients, with substantial time savings. It may serve as an efficient adjunct to routine pediatric orthodontic diagnostics, with consideration for growth-related landmark variability.
ABSTRACT Objective: This study aimed to assess whether the use of dental loupes improves the accuracy of aligner attachments and reduces the amount of composite flash after bonding. Methods: Six epoxy resin-printed models (n=14 teeth per model) were created to produce upper arches. All attachments were bonded with G-ænial Posterior composite using the same aligner template, and the protocols differed regarding the use of a dental loupe. The attachments were bonded using the dental magnifying loupe at 2.5X magnification in the “with loupe” Group 1 (n=42 teeth), and with the naked eye in the “without loupe” Group 2 (n=42 teeth). All bonded attachments were scanned and compared to those of a reference model using Geomagic Control X software to assess accuracy, with a focus on the highest deviations (defects and excesses) between the reference attachment and the results from different bonding protocols. The amounts of flash adhesive were also measured. Independent Samples T-test and Mann-Whitney U test were used. The significance level was set at 0.05. Results: The maximum deviation in excess was 0.46 mm (0.2-1.21) in Group 2, which was higher than the value in Group 1 (0.38 mm, 0.18-0.79) (p=0.048). Regarding the flash adhesive area, the “without loupe” group showed a significantly higher value (42.01±10.32 mm²) compared to the “with loupe” group (31.79±5.38 mm²) (p<0.001). Conclusions: Using a magnifying dental loupe revealed significantly lower values in both the flash adhesive area around the attachment and the maximum vertical excess on the attachment surface. Clinicians are advised to use dental loupes during bonding attachments.
ABSTRACT Introduction: Cephalometry has long been a cornerstone of orthodontic diagnosis and treatment planning. While traditionally performed manually, cephalometric analysis has increasingly shifted toward semi-automated or fully automated computer-based software, due to advances in technology. Objective: This study aims to evaluate and compare the accuracy of anatomical landmarks identified manually by orthodontists using digital tools versus those identified automatically by various artificial intelligence (AI)-based cephalometric software. Methods: A total of 25 lateral cephalometric radiographs were selected for analysis. Manual landmark identification was independently performed by two orthodontists using the digital cephalometric software NemoCeph. These were compared to the automatic landmark identifications generated by two AI-based programs: CephNinja and WebCeph™. A total of 17 anatomical landmarks, 15 hard tissue and 2 soft tissue points, were evaluated. The 17 cephalometric landmarks selected in this study are among the most commonly used and reliably identifiable reference points in the literature. To facilitate direct visual comparison, landmark positions derived from all three methods were overlaid using semi-transparent image layers. One-way ANOVA and intraclass correlation coefficient (ICC) tests were conducted to assess inter-method differences. The threshold for statistical significance was set at p < 0.05 and p < 0.01. Results: Statistically significant differences were observed at the porion, basion, gonion, and the apexes of the upper and lower incisors (p < 0.05). Compared to the manual tracings in NemoCeph, AI-based software generally placed these landmarks in more distal and superior positions. Among the AI tools, CephNinja showed greater similarity to NemoCeph for the gonion and basion points, while WebCeph™ was closer at the incisor apexes. Conclusion: Although AI-based cephalometric software offers rapid and reproducible assessments, certain anatomical landmarks - particularly porion, basion, gonion, and the apexes of the upper and lower incisors - demonstrate statistically significant positional discrepancies, compared to manual tracings. Clinicians should be cautious when relying exclusively on automated analyses for diagnostic or treatment planning purposes, since AI struggles with certain landmarks, due to algorithmic limitations.
ABSTRACT Introduction: In-depth knowledge of orthodontic mechanics is a mandatory aspect for all orthodontists, regardless of the technique, material, or appliance used. Following this reasoning, in addition to notorious knowledge, the clinician needs to be creative to deal with the countless possibilities inherent to clinical diversity. Objective: The objective of this article is to present 10 clinical situations in which the orthodontist’s inventive capacity is a fundamental element in selecting ideal mechanics to solve different clinical challenges. Results: Incorporating creativity enabled efficient resolution of all clinical situations. Conclusions: Stimulating creativity is essential to prepare professionals capable of innovating responsibly.
ABSTRACT Objective: This study aimed to analyze the dimensional stability of 3D resin-printed models for orthodontic aligners under specific storage conditions over a period of up to six months. Methods: A model of the upper arch of a dental mannequin (Orbital Bone) was scanned using the 3Shape Trios 3 scanner, to create digital models (n = 20), which were printed on the Anycubic Photon X6 KS printer and stored in a dark box at room temperature for six months. Dimensional analysis was performed by comparing the meshes of the models through superimposition at the following time points: T0 - immediately after printing (control group), T1 - 1 month, T2 - 3 months, and T3 - 6 months of storage. The Ortho Analyser software was used for this purpose, and measurements were performed by a single, trained examiner. After confirming normality (p > 0.05, Shapiro-Wilk test), Analysis of Variance (ANOVA) was applied to verify dimensional changes in the following regions of the dental arch: incisors, canines, premolars, and molars. Results: Dimensional changes in the models were not statistically significant (p > 0.05) during the storage period for all evaluated regions. However, the greatest dimensional changes occurred during the first month and in the molar region (0.175 mm), which showed a tendency to expand. Conclusions: After six months of storage in a light-free environment, the 3D-printed models exhibited minor dimensional changes, which may have some clinical impact on aligner treatment, particularly in the molar region.
ABSTRACT Introduction: Pain in orthodontic treatments results from an inflammatory process due to the application of forces. Despite photobiomodulation having shown effectiveness in reducing pain sensitivity, the method requires multiple sessions, which complicates its practical application in orthodontic clinics. Objective: To test a simplified protocol of photobiomodulation with a single application in adults undergoing orthodontic treatment. Material and methods: This single-blind, randomized, crossover study evaluated 30 participants undergoing fixed orthodontic treatment. Half of them received a single application of photobiomodulation, while the other half received a placebo, with group crossover after one month. The application was performed at 10 points using a GaAlAs diode laser (100 mW/cm2) immediately after appliance activation. Pain was assessed using a visual analog scale (VAS) at T0 (before the orthodontic check-up appointment), T24h (24 hours after the orthodontic control appointment), and T48h (48 hours after the orthodontic control appointment), and data were analyzed using two-way repeated measures ANOVA (time and intervention). Results: A total of 27 participants were evaluated. Pain was significantly higher at T24h than at T48h in both groups. Although there was no difference in pain sensitivity between the groups at T24h, pain significantly decreased in the intervention group after 48 hours. The variables of sex and age did not influence pain perception. Conclusion: The study shows that photobiomodulation can help control orthodontic pain, being well accepted by participants and not extending clinical time. However, the analgesic effects are still limited, indicating the need to refine the protocol to enhance its effectiveness.
ABSTRACT Introduction: Fixed orthodontic appliances can serve as a breeding ground for bacterial accumulation and colonization, which are responsible for the development of white spot lesions (WSLs). Objective: This study evaluated and compared the antibacterial activity of chitosan nanoparticle-coated and uncoated nickel-titanium (NiTi) orthodontic archwires against Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus). Material and Methods: Thirty patients received 0.016-in NiTi archwires, using a split-mouth design. Sixty archwires were randomized into two groups: Group A, nanochitosan-coated (n = 30, experimental), and Group B, uncoated (n = 30, control). Allocation was determined using sequentially numbered, opaque, sealed envelopes prepared by an independent researcher, with assignments concealed until allocation. The ionic gelation technique was used for coating. After six weeks in the oral cavity, archwires were retrieved, and bacterial presence was evaluated as Colony Forming Units (CFUs), through culture formation. Results: A statistically significant difference was observed in the mean CFU counts of S. mutans and L. acidophilus between the experimental and control groups (p < 0.001). The mean CFU values for S. mutans were 0.12 × 106 CFU/ml (SD ± 0.38; experimental) and 1.82 × 106 CFU/ml (SD ± 0.69; control). For L. acidophilus, mean CFUs were 0.036 × 106 CFU/ml (SD ± 0.06; experimental) and 1.96 × 106 CFU/ml (SD ± 0.65; control). Conclusion: Orthodontic archwires coated with nanochitosan demonstrated significantly greater antimicrobial activity against S. mutans and L. acidophilus compared with uncoated archwires.
ABSTRACT Introduction: This study aimed to evaluate the impact of varying degrees of anterior diastema and crowding on the precision of 3D-printed dental models using digital superimposition techniques. Materials and Methods: A digital maxillary arch model was modified in the anterior region (canine to canine) to simulate three levels of diastema (2.5 mm, 5 mm, 10 mm) and four levels of crowding (3 mm, 6 mm, 9 mm, 12 mm), along with an unmodified control. Eight digital models were fabricated using LCD 3D printing, with 15 prints per group. Printed models were scanned and superimposed onto their respective reference models using Geomagic Control X. Surface deviations were analyzed via minimum, maximum, root mean square (RMS), and average positive and negative values. One-way ANOVA and Tukey’s HSD post-hoc test were used for statistical evaluation. Results: Significant differences were observed among diastema groups (p < 0.05), with the 5 mm group showing the widest deviation range. RMS and average deviation values were highest in the 2.5 mm and 5 mm diastema conditions. In the crowding groups, significant deviations in minimum and maximum values occurred only in the 12 mm group (p < 0.001 and p < 0.008, respectively). Conclusion: Severe anterior crowding (12 mm) and mild to moderate diastemas (≤5 mm) significantly impair the precision of 3D-printed dental models. These results highlight the importance of assessing digital model fidelity in cases with anterior spacing or crowding, to ensure accurate diagnosis and appliance fabrication.
ABSTRACT Introduction: Thermoplastic materials used for retainers, aligners, and occlusal splints may degrade when exposed to common beverages and mouthwashes, affecting mechanical properties and aesthetics. Objective: To evaluate the effects of carbonated drinks, alcoholic beverages (brandy), and mouthwashes on the mechanical properties and colour stability of various orthodontic thermoplastics. Material and Methods: A total of 144 samples from six thermoplastic materials (Erkodur, Duran, Erkodur-Al, CA Pro+, Erkoflex, Bioplast) were immersed daily for 10 minutes over 14 days in artificial saliva, brandy, carbonated drink, or chlorhexidine mouthwash. Mechanical properties (yield strength, stiffness, elastic modulus) were measured via universal testing machine; colour changes (ΔE) were assessed with a colorimeter. One-way ANOVA was used for statistical analysis (p < 0.05). Results: Retainers immersed in saliva exhibited highest yield strength (Erkodur: 61.95 ± 4.21; Duran: 59.25 ± 3.12) and stiffness (Erkodur: 2.12 ± 0.19; Duran: 2.12 ± 0.23), with lowest values in carbonated drinks (Erkodur: 48.88 ± 3.32 ; Duran: 48.45 ± 5.77). Aligners and occlusal splints followed similar trends; Bioplast splints performed best mechanically (saliva: 63.05 ± 4.36 ; stiffness: 1.98 ± 0.13). Colour changes were greatest in alcoholic beverages, notably Duran (ΔE: 0.978 ± 0.21, p = 0.010) and Erkoflex (ΔE: 1.21 ± 0.06, p = 0.003); aligners and Bioplast showed minimal ΔE differences. Conclusion: Acidic and alcoholic beverages significantly reduce mechanical strength and compromise aesthetics of thermoplastic orthodontic appliances. Bioplast exhibited superior mechanical performance among splints, while aligners demonstrated minimal discoloration. Patient education on limiting exposure to such beverages is crucial to maintain appliance durability and optimal treatment outcomes.
