CAD/CAM-based 3D-printed and PVS indirect bonding jig system accuracy: a systematic review, meta-analysis, and comparative analysis of hard and soft CAD/CAM transfer trays.

BACKGROUND: The widespread use of CAD/CAM transfer trays warrants evaluation of their accuracy as compared to PVS transfer trays. OBJECTIVES: To quantify the accuracy of CAD/CAM and PVS transfer trays, investigating any differences between soft and hard trays CAD/CAM transfer trays. SEARCH METHODS: Eight different databases (Scopus, Web of Science, PubMed, Google Scholar, ProQuest, Embase, Cochrane Library, ClinicalTrials.gov) were searched, without restrictions, up to an end date of February 2023. SELECTION CRITERIA: Clinical trials (randomized and non-randomized) and in vitro studies reporting average imprecision values for bracket positioning obtained by digital superimpositions of digitally planned and real positions. DATA COLLECTION AND ANALYSIS: Data eligibility, data extraction, and risk of bias (RoB-2 and ROBINS-I) were conducted independently. The data, where possible, were synthesized and quantitatively analysed (meta-analysis of mean differences with 95% confidence intervals). The Grade of Recommendation, Assessment, Development and Evaluation (GRADE) analysis of the quality of evidence was performed. The t-test for independent samples was used to compare the transfer accuracy of hard and soft CAD/CAM transfer trays. RESULTS: Thirteen studies were synthesized in this systematic review, and then eight studies were included in the quantitative meta-analysis. As regards linear measurements, there was a mean transfer error of 0.0752 mm (95%CI: 0.0428, 0.1076) for mesiodistal measures, 0.0943 mm (95%CI: 0.0402, 0.1484) for vertical, and 0.0815 mm (95%CI: 0.0469, 0.1160) for buccolingual. As for angular measurements, there was an average transfer error of 1.2279° (95% CI: 0.6011, 1.8548) for inclination, 0.9397° (95%CI: 0.4672, 1.4123) for angulation, and 0.8721° (95%CI: 0.4257, 1.3185) for rotation. CAD/CAM transfer trays were less accurate than polyvinylsiloxane (PVS) transfer trays, with those made of soft material being more accurate than the hard ones, except for vertical dimension. The GRADE quality of evidence ranged from very low to moderate. CONCLUSIONS AND IMPLICATIONS: CAD/CAM transfer trays provide high bracket positioning accuracy, with soft transfer trays offering greater precision than rigid ones. Future randomized prospective trials are required to enhance the strength of the available evidence. REGISTRATION: Prospero (CRD42023401278 number).

Accuracy of 3D facial scans: a comparison of three different scanning system in an in vivo study.

BACKGROUND: The aim of the study was to compare the accuracy and reproducibility of three different 3D facial scanning systems, relying, respectively, on stereophotogrammetry, structured light and a smartphone app and camera. METHODS: Thirty subjects have been scanned with three different facial scanning systems, stereophotogrammetry, structured light and a smartphone app and camera. Linear measurements were compared with direct anthropometries measured on the patient's face, while the study of areas (forehead, tip of the nose, chin, right and left cheek) was evaluated by overlapping scans using the Geomagic Control X program. Statistical analyses were conducted using IBM SPSS v28 software. RESULTS: The ANOVA test was used to compare linear distances and direct anthropometry measurements, revealing statically significant values for all distances investigated, especially for the Face Hunter scanner, except for the Prn-Pog' distance (p = 0.092). The three facial scans were superimposed pairwise almost the 100 per cent of the overlapping areas fell within the tolerance limits for all three comparisons analysed. The chin was the most accurately reproduced, with no differences among scanners, while the forehead proved to be the least accurately reproduced by all scanners. CONCLUSIONS: All three acquisition systems proved to be effective in capturing 3D images of the face, with the exception of the Face Hunter scanner, that produced statistically significant differences in linear measurements for the distances Tr-Na' and Zyg-Zyg with respect to direct anthropometric measurements.

Survival rate of indirectly bonded brackets using single vs. two-component orthodontic adhesive: A 12-month split-mouth clinical trial.

Objective: Compare the bonding survival rate of two distinct bonding materials: Ortho Solo + Gradia LoFlo Resin and single component GC Ortho Connect. Materials and Methods: Indirect bonding fixed appliance treatment was required for 26 consecutive patients, 8 males and 18 females, with a mean age of 22.1 +/- 4.2 years. All patients were treated with SWM (Straight-Wire Mirabella) technique (Sweden and Martina, Due Carrare, Padova, Italy). Each patient's bonding process followed a contralateral pattern. Firstly, a 37 % orthophosphoric acid etching gel was used for 20 s, subsequently the single or two components light-cured adhesives were applied through a split-mouth cross-arch procedure. The patients underwent a 12-month follow-up period and brackets failures were rebounded, but not further included in the study. Statistical analysis was performed to analyse the survival rate of the bonding materials and the influence of the variables, with a significant level of α = 0,05. Results: The GC Connect group was used on 349 teeth, while the Ortho Solo + Gradia group was used on 351 teeth, and the indirect debonding rate was respectively 17.5% and 12.8%. With respect to the total sample, statistically significant values were found for both sex and dental arch. The bracket's survival rate for incisors, canines, premolars and molars was not significant. However, a higher debonding rate was clinically appreciable in upper and lower molars. Conclusion: In a 12-months observation period, considering all maxillary and mandibular teeth the indirect survival rate for the group GC Ortho Connect and Ortho Solo + Gradia was respectively 82.5% and 87.2%. Although the difference was not significant, a pronounced tendency to debonding for the single component group was appreciable from a clinically point of view.

Evaluation of effectiveness and efficiency of fixed orthodontic treatment comparing standard and computer-aided design and manufacturing conventional bracket systems using indirect bonding for both: A retrospective study.

BACKGROUND: To compare the effectiveness and efficiency of orthodontic treatment (OT) with standard versus computer-aided design and computer-aided manufacturing (CAD/CAM) indirect bonding of conventional brackets. METHODS: This retrospective study examined two groups: standard indirect bonding group (12 males, 13 females; mean age 12.21 ± 0.52 years), and digital indirect bonding group (11 males, 14 females; mean age 12.76 ± 1.32 years), treated via a CAD/CAM indirect bonding system. Conventional brackets were used in both groups. Pretreatment and post-treatment records were acquired for all subjects. Weighted Peer Assessment Rating (W-PAR) index was used to assess the effectiveness of OT, in conjunction with five angular cephalometric measurements (ANB°, Sn-GoGn°, U1-PP°, IMPA° and FMA°) and comparatively analyzed using generalized mixed-effects models and post hoc test. Treatment efficiency was assessed in terms of the numbers of bracket repositionings, archwire bends, accidental bracket debondings, appointments and treatment months. Comparative analysis of efficiency was performed using the asymptotic Wilcoxon-Mann-Witney test. Statistical significance was set at 5%. RESULTS: Total W-PAR and W-PAR component scores decreased significantly during treatment for both groups and in a similar way. Cephalometric measures ANB° and IMPA° significantly decreased and increased, respectively. Significantly fewer bracket repositionings, number of appointments and treatment months were recorded in group digital indirect bonding. CONCLUSIONS: Although both methods investigated were effective to achieve good outcomes, CAD/CAM indirect bonding method increased the efficiency of OT, when conventional brackets are used.

Obstructive Sleep Apnea in Developmental Age: 22-Item Pediatric Sleep Questionnaire for an Observational Descriptive Investigation.

The aim of this paper is to perform an observational descriptive study of the Obstructive Sleep Apnea Syndrome (OSAS) in a population of children by evaluating the prevalence and role of sex and age variables. The 22-item Pediatric Sleep Questionnaire (PSQ) was administered to parents of children aged 3 to 12 years. The questionnaire is a very simple tool since it allows for the indication of patients with possible OSAS diagnosis through a cut-off of 0.33. The anonymous diagnostic questionnaire, available in digital format, was administered to the population under study by a link or QR code. Only the questionnaires completed in all their parts were recorded and analyzed. Eight hundred and thirty-two questionnaires were collected. One hundred and fifty-four subjects obtained a PSQ score > 0.33 and the prevalence of OSAS was 18.51%. The Chi-square test showed a statistically significant association between the PSQ score > 0.33 and male sex. The higher prevalence of subjects with a value of PSQ > 0.33 (n = 277) are aged 3-4-5 years, followed by the 6-7-8 range in the group with PSQ score > 0.33, p < 0.05. The prevalence of OSAS was 18.51% in children aged 3 to 12 years. The variables male biological sex and the age group 3-8 year were statistically significant for subjects with OSAS diagnosis. This study underlines the use of the 22-item Pediatric Sleep Questionnaire as a first screening tool to identify children at risk of OSAS.

Accuracy of planned tooth movement with lingual straight wire technique.

OBJECTIVES: To analyze the accuracy of planned tooth movements of torque, tip, rotations, and transverse width values with lingual straight-wire technique. MATERIALS AND METHODS: 40 Caucasian subjects with mean age of 23.9 years, consecutively treated in private practice with a lingual straight-wire appliance (STb, Ormco, Glendora, Calif) were evaluated. Maxillary and mandibular dental casts were taken before treatment (T0), in the setup (T1), and at the end of treatment (T2) and scanned with an intraoral 3D scanner Carestream CS 3600 (Carestream Dental, Atlanta, GA). Virtual models at the three time points were superimposed on T1 using 3D software, and the coordinates were exported as a set of x, y, and z values. Angular and linear measurements were analyzed to measure torque, tip, rotation movements, and transverse intra-arch widths. Changes among the three time points were analyzed with Friedman's nonparametric test. RESULTS: A general increase in torque was recorded in the setup and in the final result, except for the maxillary molars. Torque, tip, and rotation movement mean accuracy was ≥84% for incisors, canines, and premolars. A general increase in transverse width was measured in the setup and in the final models, except for the upper second molars, which showed reduced transverse width during treatment. CONCLUSIONS: The movements planned in the setup to obtain the ideal torque, tip, and rotations actually occurred, except for second molars, which showed less accuracy. Planned expansion of the arches occurred only partially.

Stress Relaxation Properties of Five Orthodontic Aligner Materials: A 14-Day In-Vitro Study.

We aimed to investigate the stress relaxation properties of five different thermoplastic aligner materials subjected to 14 days of constant deflection. Five different thermoplastic aligner materials were selected, whose elastic properties varied: F22 Evoflex, F22 Aligner, Durasoft, Erkoloc-Pro and Duran. The static properties of these materials-in particular, stiffness, stress-strain curve and yield stress-were measured with a three-point bending test. For all the tests that were performed, a minimum of three samples per material were tested. The yield load, yield strength, deformation and particularly the stiffness of each material were found to be similar in the single-layer samples, while the double-layer samples showed far lower stiffness values and were similar one to another. F22 Evoflex and Erkoloc-Pro maintained the highest percentages of stress, 39.2% and 36.9%, respectively, during the 15-day period. Duran and Durasoft obtained the lowest final stress values, 0.5 MPa and 0.4 MPa, respectively, and the lowest percentage of normalized stress, 4.6% and 3.9%, respectively, during the 15-day period. All the materials that we tested showed a rapidity of stress decay during the first few hours of application, before reaching a plateau phase. The F22 Evoflex material showed the greatest level of final stress, with relatively constant stress release during the entire 15-day period. Further research after in vivo aging is necessary in order to study the real aligners' behavior during orthodontic treatment.

Comparative analysis of intraoral scanners accuracy using 3D software: an in vivo study.

BACKGROUND: The purpose of the present in vivo study was to compare the accuracy, in terms of trueness, between full-arch digital impressions of different intraoral scanning systems, using as a reference the ideality of the conventional impression technique. METHODS: Polyvinyl siloxane (PVS) two-step technique impressions of 27 subjects were taken, and the stone casts were scanned using desktop scanners R500 3Shape. For each arch, in vivo scans were taken with intraoral scanners Carestream CS3600, CEREC Omnicam and Trios 3Shape. All the files were compared, superimposing them on the reference model to calculate the total 3D and 2D deviations. The efficiency of the digital and conventional workflows was evaluated by measuring the work time in minutes. Statistical analyses were performed using R software (R Core Team 2020) with a p-value < 0.05. RESULTS: The three intraoral scanners differed from the PVS impression by differences of the order of 100-200 µm, and there was a trend of greater imprecision in the molar area in both dental arches. In comparison with PVS technique, CEREC tended to reduce the size of the impression, Trios presented the trend of greater precision, and Carestream showed minor differences the transversal distance. The areas of greatest discrepancy both in excess and in defect with respect to the PVS impression were the molar areas and incisal margins. Trios 3Shape recorded the shortest times and therefore with a more performing speed. CONCLUSION: The Trios 3Shape was found to be the most accurate single-tooth scanner, while the Carestream CS 3600 showed better inter-arch diameter performance compared to PVS impressions. The 3D and 2D analyses showed a trend of greater distortion of the impressions compared to the conventional one in the molar region.

Severe transverse discrepancy in adult Class III patient: Parallel rapid palatal expansion with a bone-borne tandem expansion screws (TSE) followed by lingual fixed appliance for a non-surgical treatment: A case report.

INTRODUCTION: Midpalatal suture opening in young adults is often difficult to achieve, depending on the suture maturation stage. It has been suggested that it is possible to avoid surgery and still achieve a successful pure skeletal expansion if a bone-borne Miniscrew-Assisted Rapid Palatal Expander is chosen (MARPE). CASE PRESENTATION: The following case report describes the use of a pure bone-borne miniscrew-assisted rapid palatal expander followed by lingual fixed appliance to correct a severe transversal discrepancy in an adult patient characterized by a hyperdivergent mandibular skeletal pattern. MANAGEMENT AND OUTCOMES: All treatment phases were digitally planned, starting with the miniscrews' insertion with a three-dimensionally printed surgical guided (Miniscrew Assisted Palatal Application: MAPA system) and Tandem Skeletal Expander (TSE) appliance, to the lingual indirect bonding. The final outcomes confirmed that this orthodontic approach represented a valid alternative to orthognathic surgery, with a significant improvement of the patient's occlusion and facial appearance. DISCUSSION: The Tandem Skeletal Expander (TSE) design and the expansion protocol applied allowed to obtain a significant and stable skeletal increase of transversal diameters by digital planning of the insertion of miniscrews, with lower risks and costs than other surgical approaches.

Comparison of the accuracy of digital face scans obtained by two different scanners.

OBJECTIVES: To compare the degree of accuracy of the Face Hunter facial scanner and the Dental Pro application for facial scanning, with respect to both manual measurements and each other. MATERIALS AND METHODS: Twenty-five patients were measured manually and scanned using each device. Six reference markers were placed on each subject's face at the cephalometric points Tr, Na', Prn, Pog', and L-R Zyg. Digital measurement software was used to calculate the distances between the cephalometric reference points on each of the scans. Geomagic X Control was used to superimpose the scans, automatically determining the best-fit alignment and calculating the percentage of overlapping surfaces within the tolerance ranges. RESULTS: Individual comparisons of the four distances measured anthropometrically and on the scans yielded an intraclass correlation coefficient index greater than .9. The t-test for matched samples yielded a P value below the significance threshold. Right and left cheeks reached around 60% of the surface, with a margin of error between 0.5 mm and -0.5 mm. The forehead was the only area in which most of the surface fell within the poorly reproducible range, presenting values out of tolerance of more than 20%. CONCLUSIONS: Three-dimensional scans of the facial surface provide an excellent analytical tool for clinical evaluation; it does not appear that one or the other of the measuring tools is systematically more accurate, and the cheeks are the area with the highest average percentage of surface in the highly reproducible range.