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To compare viscoelastic behavior of thermoplastic and thermoset elastomeric chains after 30 days of intraoral exposure and to evaluate influence of color on mechanical performance and color stability. Twenty patients in the retention phase wore Hawley retainers containing four elastomeric chain segments: gray thermoplastic, transparent thermoplastic, gray thermoset, and transparent thermoset (n = 20 per group). Chains were stretched to a standardized distance of 20 mm and worn intraorally for 30 days. Dimensional deformation, tensile force at 20 mm and at 2 &#xd7; and 3 &#xd7; stretching, rupture force, and color change were assessed at baseline and after intraoral exposure. Data were analyzed using factorial analysis of variance with Tukey's post hoc test and paired t-tests (&#x3b1; = .05). Thermoplastic elastomeric chains exhibited significantly greater permanent deformation than thermoset chains (P < .0001). Although thermoplastics generated higher initial tensile forces, they showed greater force degradation after intraoral exposure, whereas thermoset elastomers maintained higher residual forces at the tested activation distance of 20 mm. Thermoplastic chains exhibited higher rupture forces but greater reductions from baseline, while thermoset elastomers demonstrated superior elastic recovery. Transparent elastomers showed greater color change (&#x394;E) than gray elastomers; however, all &#x394;E values remained within clinically acceptable limits. After 30 days of intraoral exposure, thermoset elastomeric chains demonstrated superior mechanical stability and force retention compared with thermoplastic chains. Although transparent elastomers were more susceptible to discoloration, esthetic changes remained clinically acceptable. These findings reflect elastomeric behavior under controlled intraoral conditions.

To evaluate the impact of three thermoforming methods on the resulting thickness of clear aligners (CAs). A sample of 30 clear aligners (CAs) from the upper jaw was produced with polyethylene terephthalate glycol and divided into three groups according to thermoforming technique: pressure thermoforming (PRT; n = 10), digital air vacuum thermoforming (DVT; n = 10), and conventional air vacuum thermoforming (CVT; n,=,10). Micro-computed tomography scans and thickness values at reference points were obtained in resulting images. Intrainvestigator reliability was assessed, and statistical analysis of data was performed with nonparametric analysis of variance tests (P < .05). Thickness decrease was detected among the three groups, which showed statistically significant differences. CVT presented the lowest mean thickness of 380 &#xb5;m (&#xb1;72.3 &#xb5;m), with teeth in the anterior region thicker overall than the first molar. Also, this group had the greatest variability. DVT recorded a mean of 429 &#xb5;m (&#xb1;67.2 &#xb5;m), with more uniform anteroposterior thickness distribution. Meanwhile, PRT had less substantial thinning with a mean thickness of 467 &#xb5;m (&#xb1;81.7 &#xb5;m). Thermoforming method influences the surface thickness of thermoformed CAs. The findings provide clinically relevant evidence to guide orthodontists in selecting thermoforming protocols that ensure aligner structural stability, thickness uniformity, and more predictable force delivery.

To assess the acceleratory effect of locally administered injectable platelet-rich fibrin (i-PRF) on overall treatment duration (OTD) and root resorption. Patients with anterior crowding requiring extraction of all four first premolars were randomized into i-PRF and control groups, both treated with fixed appliances. The i-PRF group received submucosal injection of i-PRF distal to all canines on the buccal and palatal sides, and canine retraction was performed using sectional mechanics. A second i-PRF injection was administered in the anterior interradicular region, followed by alignment up to 0.018 &#xd7; 0.025&#x2033; stainless steel and space closure with NiTi closed coil springs (150 g). Control patients underwent the same protocol without i-PRF injections. Treatment duration was calculated; root resorption was assessed using cone-beam computed tomography, and volumetric analysis was accomplished using MIMICS software. All 30 enrolled patients (17 females, 13 males; mean age 16.6 &#xb1; 2.7 years) completed the study, with 15 patients in each group. The mean OTD was 338.6 &#xb1; 37.8 days for the i-PRF group and 374.3 &#xb1; 49.3 days for the control group (P = .107). The percentage root volume loss for the central incisor was 3% and 4% in the intervention and control groups (P = .122), respectively, and 5% and 6% for the lateral incisor in the intervention and control groups (P = .767). Both the treatment duration and root volume loss in both groups were statistically and clinically nonsignificant. The use of i-PRF did not significantly reduce OTD or affect root resorption compared with the control group.

To compare the effectiveness of clear aligner (CA) vs removable inclined plane (RP) in improving the dentofacial changes and oral health-related quality of life (OHRQoL) in children with anterior crossbite in the mixed dentition. Twenty-four pseudo-Class III patients in the mixed dentition (8-12 years) were randomly allocated into two equal groups: the CA group treated with clear aligners, and the RP group treated with removable inclined planes. Lateral cephalometric analysis and OHRQoL questionnaires were conducted immediately before and after 4 months of intervention. The primary outcome included cephalometric changes, whereas the CPQ8-10 (children's perception questionnaire) was the secondary outcome. Data analysis included paired t-tests, independent t-tests, the Shapiro-Wilk test, the Wilcoxon signed-rank test, and the Mann-Whitney test. Significant differences were observed between the two groups for changes in U1-SN, IMPA, L1-NB angles, and L1-NB (mm) (P < .05). However, there was no significant difference in improving the OHRQoL of patients between the CA and RP groups (P > .05). Both treatment approaches resulted in similar improvement in the patients OHRQoL. However, the CA group resulted in more significant proclination of the upper incisors, while the RP group showed more significant retroclination of the lower incisors.

To demonstrate systematic patterns relating "subjective" and "objective" measurement when scoring the American Board of Orthodontics Discrepancy Index (DI) and Objective Grading System (OGS) and Peer Assessment Rating (PAR) indices. Digitized records of study models from 108 subjects scored by three trained raters were compared with scores from a proprietary digital scanning system with a built-in algorithm for producing these indices. Repeat measures of consistency using the digital system were perfect. Interrater consistency was typically moderately high (median ICC = 0.866). Correlations between human and digital measurement methods for the 33 component and index scores ranged from median intraclass correlation coefficients of 0.826 for DI, 0.568 for OGS, and 0.775 for PAR pretreatment and 0.636 for post-treatment PAR. The relationship between subjective and objective assessments showed common relationships: slopes significantly less than 1.00, and overestimation of small values and underestimation of large values. This pattern, known as the "lazy-S" curve, is characteristic of orthodontic and general measurement systems. The consistency for overjet and overbite indices was better between human and digital systems than across the two indices proportion to measure the same features. The inconsistency between human and machine measurements of occlusal characteristics does not necessarily reflect inadequacy of either approach and may be interpreted instead as reflecting features of judgment orthodontists use to focus on the clinically most relevant data.

To compare transfer accuracy between a three-dimensionally (3D) printed transfer jig and a conventional silicone tray in an in vitro setting using 3D linear measurements. 3D intraoral scans were obtained from four patients. Sixteen 3D-printed models (eight maxillary, eight mandibular) were prepared for each group. In Group 1, brackets were digitally positioned using 3Shape Ortho Analyzer software and transferred from working to posttransfer models using eight 3D-printed jigs. In Group 2, eight silicone trays were fabricated for bracket transfer. Working and posttransfer models were superimposed using Geomagic software, and divergence was summarized as the median and interquartile range. Tooth-level deviations between methods were compared using the Wilcoxon signed-rank test, stratified by arch and tooth type. Statistical significance was set at P < .05. Although a statistically significant difference between methods was observed (P = .024), median deviations for both methods were within the American Board of Orthodontics clinically acceptable limit (&#x2264;0.5 mm). In the mandible, the 3D-printed jig group showed smaller positional deviations than the conventional method (P < .001). Conversely, in the maxilla, the conventional method showed smaller positional deviations (P = .003). Deviations occurred most often in the vertical and horizontal directions in the 3D-printed jig group and in the transverse and vertical directions in the conventional group. The 3D-printed jig demonstrated greater accuracy in the mandible, while the conventional silicone tray was more accurate in the maxilla. However, the differences were not clinically significant, and both techniques achieved clinically acceptable bracket transfer accuracy.

To compare the incidence of bond failures and white spot lesions (WSLs) between brackets bonded with either light-cured resin-modified glass ionomer cement (GC Fuji Ortho LC) or light-cured composite resin (3M Transbond Plus Color Change Adhesive) after 18 months of treatment. 90 patients were allocated to the trial, and 84, with a mean age of 16.7 &#xb1; 2.6 years, were analyzed. The cross-mouth method was employed in each patient, in which two diagonal quadrants (e.g., upper right and lower left, or vice versa) were randomly assigned to the FujiOrtho group, and the opposite diagonal quadrants to the Transbond group. All patients were monitored for an average of 18 months for bond failure and WSL incidence. Multilevel mixed Poisson regression with robust standard errors was used to compare the groups. Overall, failure rates were 12.9% in the FujiOrtho group and 2.1% in the Transbond group, with an adjusted relative risk (aRR) of 6.21 (95% CI: 3.89-9.94), adjusted for age, sex, maxilla/mandible, tooth position, and treating orthodontist. Overall, WSL incidence was 8.3% in the FujiOrtho group and 8.8% in the Transbond group, with an aRR of 0.95 (95% CI: 0.80-1.13). Transbond Plus demonstrated a significantly lower bond failure rate compared to GC FujiOrtho LC, with a 3.6 times reduced risk of bracket failure. There were neither statistically nor clinically significant differences in the incidence of WSLs between the two groups.

To assess color and fluorescence changes in post-orthodontic white spot lesions (WSLs) using different surface conditioning methods from prior to resin infiltration to a 24-month follow-up. Thirty patients, each with a minimum of four WSLs with ICDAS (International Caries Detection and Assessment System) II code 1 and 2 after bracket debonding were included. After baseline (T0), the lesions were randomly divided into four groups: regular brushing, 15% HCl (hydrogen chloride) gel, 37% H3PO4 (phosphoric acid) gel, and Er:YAG (erbium-doped yttrium aluminium garnet) laser. Icon resin infiltration was applied. In the treatment groups, color and fluorescence were reexamined just after the resin infiltration treatment (T1), and after 6 (T2) and 24 months (T3). There were no significant fluorescence or color changes between the treatment groups for the different time intervals. The control group showed a significantly lower color change from T0 to T2 and T0 to T3 than all the treatment groups whereas, at T2-T3, the control group showed the greatest improvement. Resin infiltration caused greater esthetic improvement and more revival of the lost fluorescence than daily brushing. HCl gel, H3PO4 gel, and Er:YAG laser are adequate conditioning methods for resin infiltration of post-orthodontic WSLs with ICDAS II code 1 and 2.

To compare and quantify anchorage loss during space closure following premolar extraction in matched groups of different facial types. Variables such as facial divergency, age, sex, and crowding were considered for cephalometric analysis. Pearson's correlation coefficient was used to determine the strength of the relationship between anchorage loss and facial divergence. Multiple regression analyses were used to investigate the factors associated with variability of anchorage loss. Average treatment duration was 41.90 &#xb1; 12.97 months. The mean anchorage loss was 3.30 &#xb1; 1.99 mm, 3.47 &#xb1; 1.95 mm, and 3.01 &#xb1; 2.39 mm for hypodivergent, normodivergent, and hyperdivergent patients, respectively. No significant differences in the amount of anchorage loss were found among the three facial groups and between sexes. Increasing age and crowding were significantly negatively associated with anchorage loss (P = .02 and < .001, respectively). Facial divergence does not significantly impact anchorage loss in orthodontic cases involving extractions. Horizontal anchorage loss decreases the mandibular plane angle, but the magnitude may not be clinically relevant. Vertical anchorage loss does not significantly change the mandibular plane angle in premolar extraction cases.

To evaluate the influence of self-esteem on oral health-related quality of life (OHRQoL) in the occlusal transition from childhood to adolescence. This longitudinal observational study involved 785 children, ranging from mixed to permanent dentition, over a 4-year follow-up period. OHRQoL was assessed using the Child Perceptions Questionnaire (CPQ) for two age groups: 8 to 10 years for those in mixed dentition and 11 to 14 years for permanent dentition. Clinical variables related to malocclusion were evaluated using the Dental Aesthetic Index (DAI), and children's self-esteem was measured using the Global Negative Self-Evaluation (GSE). Poisson regression analyses were conducted, with regression models adjusted to estimate relative risks and their respective 95% confidence intervals. A significance level of P < .20 was used for individual analyses, with an overall significance set at 5%. Individuals with low self-esteem had an 11%, 12%, 21%, and 20% higher risk of reporting a negative impact on OHRQoL in functional limitation, emotional well-being, social well-being, and total OHRQoL, respectively (P < .05). Self-esteem may contribute to decreased OHRQoL in the transition from childhood to adolescence. The findings suggest that the need for orthodontic treatment does not significantly alter this relationship in childhood and does not affect OHRQoL.

To evaluate topographic changes on the enamel surface after different debonding methods of clear aligner attachments using three-dimensional (3D) micro-computed tomography (Micro-CT). Vertical rectangular attachments were attached to 20 premolars and divided into two subgroups (N = 10) using different debonding methods. Micro-CT scans were performed showing the enamel surfaces of each group before bonding (T0), after the first debonding procedure (T1), and after the second debonding with polishing (T2). In Group 1, excess attachment composite was removed with a 12-blade carbide bur, followed by a 24-blade carbide bur, and then the tooth surface was polished with a Renew stone. In Group 2, the attachment composite was removed with a Komet-H23VIP bur and polished with a compatible polishing kit. Morphological changes in the enamel surface were compared within groups using repeated-measures analysis of variance and between groups using independent samples t-tests. Values of P < .05 were considered statistically significant. Significant decreases in enamel demineralization volume (P < .001), area (Group 1: P < .001; Group 2: P = .020), and mineral density (P < .001) were observed in both groups. Intragroup comparison revealed no significant difference in demineralization volume or area changes, but enamel mineral density was better preserved in Group 2 (T1-T2, P = .006; T0-T2, P = .008). The cumulative effect of repeated attachment debonding is significant, with tissue loss becoming more pronounced after the second application. The need for refinement should be carefully evaluated.

To compare the performance of ChatGPT-4 Turbo and Gemini 1.5 Pro in the domain of Clear Aligner Therapy (CAT). A total of 36 standardized questions on CAT were created based on consent forms from aligner companies and frequently asked patient questions. Responses were generated by ChatGPT-4 Turbo and Gemini 1.5 Pro. A reference answer key was developed from current literature. Two orthodontic professors independently evaluated the responses using a six-point accuracy scale and a three-point completeness scale. Questions were also categorized by topic. Readability was assessed using Flesch-Kincaid Grade Level (FKGL) and Simplified Measure of Gobbledygook (SMOG) scores. Independent samples t-tests were used to compare readability, whereas the Mann-Whitney U test was used for accuracy and completeness. Interrater reliability was assessed with intraclass correlation coefficient (ICC). Significance was set at P < .05. Interrater reliability was high for both models. ChatGPT showed excellent agreement for accuracy (ICC = 0.91) and good for completeness (ICC = 0.89). Gemini also showed excellent accuracy (ICC = 0.93) and moderate-to-good completeness (ICC = 0.78). No significant differences were found between models in accuracy, completeness, or readability. Both produced content with FKGL scores indicating university-level reading and SMOG scores suggesting high school-level comprehension. The readability of the content may present challenges for general audiences due to its complexity. The models used in this study may assist in patient education; however, the results implied the importance of professional consultation and careful interpretation of artificial intelligence-generated information.

To evaluate the biological response of mandibular central incisors to anterior bite turbos (ABTs) during fixed orthodontic treatment, focusing on pulpal blood flow (PBF), tooth mobility, and pain perception. Fifty-five patients undergoing fixed appliance therapy were assigned to two groups: an experimental group (n = 29) and a control group (n = 26). All received 0.014-inch nickel-titanium arch wires. ABTs were bonded to the palatal surfaces of the maxillary central incisors in the experimental group. Lower incisor PBF was measured using laser Doppler flowmetry at baseline, 20 minutes, 1 week, and 1 month after bonding. Tooth mobility was recorded after 1 month using the Miller Index. Pain was assessed using a 10-cm Visual Analogue Scale over 7 days. PBF declined after 1 week in both groups and recovered after 1 month, with no significant differences between groups (P > .05). Tooth mobility was significantly greater in the bite turbo group (P < .001), with 74.1% of patients showing Grade 2 mobility compared with 25% in the control group. Pain peaked within 24 hours and declined significantly by day 7 (P < .001) in both groups, with no significant between-groups differences. ABTs do not adversely affect pulpal circulation or pain perception. The increase in tooth mobility in the bite turbo group is a normal adaptive response and remains within safe clinical limits. Using ABTs to correct deep overbite is biologically safe.

To investigate the effect of beveling side (apical vs occlusal) on the extrusive biomechanics of clear aligners compared to unbeveled attachments when tracking issues occur. An in vitro Orthodontic Force Simulator (OFS) was used to simulate extrusion of a maxillary canine and first molar. Three attachment designs (beveled apical, beveled occlusal, and conventional rectangular) were digitally designed on the target teeth and directly milled in zirconia material. Aligners were thermoformed for each design and target tooth. The tooth-aligner mismatch was created on the target tooth up to 1.0 mm to simulate the tracking issue. Finite Element Analysis (FEA) was conducted to simulate the OFS experiment and analyze stress distribution and deformation. The attachment designs yielded significant differences in extrusion forces and bucco-palatal moments on both teeth. Beveled apical attachments consistently produced the lowest forces and moments, especially as displacement increased. This was attributed to a sliding motion of the aligner along the tooth movement path, mitigating the negative effects of tracking errors. Rectangular and beveled occlusal attachments, while offering strong initial engagement, resulted in higher stress concentrations and variability in force delivery as the simulated aligner-tooth mismatch grew. The beveled apical design provides more predictable and consistent extrusion forces, reducing unwanted side effects, particularly for large movements and high risk of tracking issues.

To evaluate the effect of miniscrew-assisted rapid palatal expansion (MARPE) on root resorption, buccal bone thickness, and tooth inclination. This study included 30 patients with maxillary constriction who were treated with MARPE. The device was left in place for 6 months for retention. Cone-beam computed tomography (CBCT) images were taken before treatment and after 6 months. CBCT images were analyzed for root length, buccal bone thickness, and tooth inclination for premolars and first molar on both sides. A paired t-test was used to compare between pretreatment and posttreatment root lengths, buccal bone thickness, and buccal tooth inclination. No significant differences were found between pretreatment and posttreatment root lengths of all measured teeth (P value > .05). A significant difference was found in the buccal bone thickness at the right second premolar at the levels of 2 mm and 8 mm (P = .049 and P = .039, respectively) and at the level of 2 mm for the left second premolar (P = .009). Buccal bone thickness at the right and left mesiobuccal root of the first molar at 8 mm was significantly reduced after expansion (P = .001). The difference between pre-expansion and postexpansion in tooth inclination ranged between -1.87 and 0.27. Only the inclination of the left first molar was significantly increased after expansion. No root resorption was caused by the bone-borne MARPE. No change in buccal bone thickness and inclination of most of the posterior maxillary teeth was found.

To investigate the impact of living in a war zone on acceleration of skeletal maturation and development of permanent teeth. A total of 272 Israeli children and adolescents aged 9-15 years participated in this study. The Gaza group included 106 participants from the Gaza envelope area (within 7 km of the Gaza Strip border), while the central group consisted of 166 participants from central Israel. Skeletal maturation and dental development were assessed using lateral cephalometric and panoramic radiographs, respectively. Significant differences were observed in all maturation variables, including skeletal maturation as well as maturation of the upper and lower second molars (right and left) and upper canines. The Gaza envelope group exhibited more advanced and accelerated maturation than the central group (P < .0005). Positive correlations were identified among tooth maturation, chronological age, and skeletal development (0.519 < r < 0.599). Linear regression analysis revealed that the maturation of the lower left second molar accounted for 47.8% of variance in skeletal maturation. In this study, we confirm that children living under the stress of a conflict zone exhibited earlier skeletal maturation and accelerated eruption of permanent second molars and upper canines than their peers. The early eruption of second molars and canines, particularly the lower left second molar, may serve as a predictive marker for pubertal progression.

To evaluate the relationship between skeletal classification and the anterior and posterior components of cranial base flexure and glenoid fossa position. Pretreatment cone-beam computed tomography records of 420 patients were stratified by sex, age, and skeletal classification based on standards for maxillomandibular differential for age-specific patients. Cephalometric measurements (Basion, Nasion, superior aspect of glenoid fossa) were recorded, and their angular deviation, horizontal, and vertical distance from Sella were measured using a 7&#xb0; constructed plane (H-P) from S-N as a reference. Results were analyzed using regression analysis and analysis of variance, along with intraclass correlation coefficient for reliability. Cranial base flexure was found to be significantly smaller in Class III individuals than Class I or II, due to a larger deflection in posterior cranial base angle from the horizontal plane. The position of Basion relative to Sella was also noted to have a significantly shorter horizontal and significantly longer vertical length in these same individuals. The position of the glenoid fossa showed that Class II patients tended to have a more posterior horizontal displacement from Sella when than those in Class I or III. All measurements, except for cranial base flexure, were significantly larger in males than females. Statistical significance was measured at P < .05. Cranial base angle is significantly smaller in Class III individuals, due to an anteriorly positioned posterior cranial base. The posterior position of the glenoid fossa appears to contribute to the anteroposterior position of the condyle in Class II patients.

To assess the effects of lithium on orthodontically induced root resorption (OIRR) and orthodontic tooth movement (OTM) and elucidate the underlying mechanisms in an osteoporotic rat model. Thirty 10-week-old female Wistar rats were randomly assigned to ovariectomized (OVX) or sham-operated (Sham) groups. Four weeks post-surgery, each group was further divided to receive either lithium (Li: 0.64 mM/kg) or saline via daily intraperitoneal injection. Orthodontic force was applied for 14 days using a closed-coil spring to move the maxillary first molar mesially. OTM was analyzed using micro-computed tomography on day 14. Histological analysis evaluated OIRR, apoptotic cells, osteoclasts, and odontoclasts. Immunohistochemical staining was used to assess the expression of receptor-activated nuclear factor-kappa B ligand and osteoprotegerin. OIRR was significantly higher in the OVX group than Sham groups. Lithium markedly suppressed OIRR in OVX rats to levels comparable to the Sham + Li group. Lithium significantly reduced the number of apoptotic cells on day 3, decreased the number of odontoclasts, and increased osteoprotegerin expression by day 14. It also prevented excessive tooth tipping without affecting the overall distance of tooth movement, promoting a shift from tipping to bodily movement in the OVX group. In an osteoporotic rat model, lithium effectively suppressed OIRR and promoted bodily tooth movement without reducing OTM distance, suggesting the therapeutic potential of lithium in patients with osteoporosis.

To evaluate agreement between the tooth landmark localization patterns of artificial intelligence (AI) and those from human examiners. Three-dimensional (3D) digital dental model images were obtained from 284 participants. On a total of 5583 permanent teeth, six landmarks per tooth were manually identified and annotated using custom-made 3D annotation software. To develop an AI model capable of automatically identifying tooth landmarks, a deep-learning algorithm was applied to a training dataset consisting of 4519 teeth. To select the optimal AI model, datasets of 556 and 508 teeth were used as validation and test datasets, respectively. For intraexaminer and interexaminer reliability tests, 280 teeth from 10 participants were randomly selected, and two human examiners identified the same six landmarks on two separate occasions. The mean error in tooth landmark localization of the AI model ranged from 0.01 mm to 1.68 mm. The intraclass correlation coefficient between the AI model and human examiner for all landmarks was excellent, ranging from 0.97 to 1.0. The landmark localization error from the AI model was smaller than human interexaminer differences for mesial and distal proximal points. However, errors for the cusp tip and facial axis points were greater in the AI model than the interexaminer differences. AI exhibited localization accuracy for tooth landmarks comparable with that of human examiners for specific measurements related to tooth size. Nonetheless, its accuracy still needs improvement to match that of orthodontic clinicians in identifying cusp tips and facial axis points.