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J Clin Orthod. 2022 Mar;56(3):185-186.

NO ABSTRACT

PMID:35706150

J Clin Orthod. 2022 Mar;56(3):187-193.

NO ABSTRACT

PMID:35706151

J Clin Orthod. 2022 Apr;55(4):211-220.

NO ABSTRACT

PMID:35708982

Prog Orthod. 2022 Jun 20;23(1):19. doi: 10.1186/s40510-022-00414-7.

ABSTRACT

OBJECTIVE: The stability of the transverse expansion in passive self-ligating bracket treatments is a debated topic in orthodontics. However, to date, only 3 reports are available in the literature, with the maximum follow-up of 3 years after the end of therapy. The present study aims to evaluate the stability of orthodontic treatment with self-ligating brackets in a 6-year follow-up period of time.

MATERIALS AND METHODS: A sample of 56 non-extractive cases (of whom 33 females, mean age 16.9, SD = 9.0 years) consecutively treated with Damon® system was retrospectively selected. All patients received fixed retainers from canine to canine in both arches at the end of treatment, and no removable retainers were provided. The mean values of the transverse intercusp, transverse centroid and transverse lingual distances were evaluated for all teeth from canines to second molars in both arches. Each measure was calculated at four timepoints: before treatment (T0), at the end of treatment (T1), one year after treatment (T2) and six years after treatment (T3). Transverse diameters were measured for all teeth, starting from the canines to the second molars, for a total of 1680 observations, and subsequently compared in order to evaluate intra-treatment and post-treatment modifications.

RESULTS: There were increases in all transverse dental measurements during active treatment. A statistically significant (p < .05) reduction of the transverse diameter was found, for upper and lower premolars, from T1 to T3.

CONCLUSION: The 6-year follow-up analysis detected that the initial transverse expansion showed a statistically significant relapse in premolars. No relapse was detected at the level of canines, due to the presence of fixed retainers, and minimal at first molars.

PMID:35718801 | PMC:PMC9207026 | DOI:10.1186/s40510-022-00414-7

Prog Orthod. 2022 Jul 4;23(1):21. doi: 10.1186/s40510-022-00416-5.

ABSTRACT

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.

PMID:35781850 | PMC:PMC9250910 | DOI:10.1186/s40510-022-00416-5

Int Orthod. 2022 Sep;20(3):100662. doi: 10.1016/j.ortho.2022.100662. Epub 2022 Jul 19.

ABSTRACT

This clinical case demonstrates how the use of a hybrid approach consisting of aligners, orthodontic miniscrews and partial fixed appliances can be an effective and efficient solution for recovering adequate vertical space for satisfactory implant-prosthetic rehabilitation. Specifically, massive intrusion of an upper second molar (tooth 1.7) was achieved orthodontically with direct TADs support to allow otherwise unpredictable movements and achieve maximum anchorage control for subsequent implant rehabilitation of the fourth quadrant.

PMID:35869025 | DOI:10.1016/j.ortho.2022.100662

Prog Orthod. 2022 Jul 27;23(1):34. doi: 10.1186/s40510-022-00428-1.

NO ABSTRACT

PMID:35896904 | PMC:PMC9329499 | DOI:10.1186/s40510-022-00428-1

Bioengineering (Basel). 2022 Jul 28;9(8):349. doi: 10.3390/bioengineering9080349.

ABSTRACT

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.

PMID:36004874 | PMC:PMC9405504 | DOI:10.3390/bioengineering9080349

Angle Orthod. 2022 Nov 1;92(6):714-721. doi: 10.2319/031522-220.1.

ABSTRACT

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.

PMID:36037405 | DOI:10.2319/031522-220.1

Int Orthod. 2022 Sep 9:100686. doi: 10.1016/j.ortho.2022.100686. Online ahead of print.

ABSTRACT

OBJECTIVE: To resolve a complex Class II case with unilateral crossbite through an aesthetic approach, namely a hybrid orthodontic treatment combining aligners with miniscrews and auxiliaries.

MATERIALS AND METHODS: A 14-year-old hypodivergent female patient with dental Class II and posterior crossbite presented for orthodontic treatment. The patient refused conventional fixed multibracket treatment and was therefore prescribed aligners used in association with miniscrews and sectional lingual appliances. Pre- and post-treatment records and 2-year follow-up records are presented.

RESULTS: Treatment objectives, namely ideal occlusion and improved profile, were achieved in 12 months. Post-treatment panoramic radiography showed good root parallelism, and no sign of either crestal bone height reduction or apical root resorption. The patient was satisfied with the functional and aesthetic outcomes, which were stable at 2 years.

CONCLUSION: This case report illustrates that a hybrid aligner approach may be used to treat posterior crossbite and class II malocclusion with reduced treatment times, optimal oral hygiene and excellent aesthetics.

PMID:36096935 | DOI:10.1016/j.ortho.2022.100686