The efficacy and predictability of maxillary first molar derotation with invisalign: a prospective clinical study in growing subjects

To analyze the derotation of maxillary mesio-rotated first permanent molars in subjects with Class II edge-to-edge dental malocclusion in mixed dentition treated with Invisalign Clear Aligners (CA). In total, 36 patients (16 males, 20 females, 9.9 ± 1.9 years) treated with CA are enrolled from the Department of Orthodontics. Inclusion criteria are the following: Caucasian ancestry, mixed dentition, molar Class II edge-to-edge, no tooth/craniofacial anomalies, no caries/periodontal diseases. Pre-treatment (T1) and post-treatment (T2) digital casts, and final ClinCheck representations (T2ClinCheck) are acquired. The Henry’s angle (HA) is used to assess maxillary first molars rotation. The molars with an HA > 11° are taken (53 teeth). Five measurements are performed at T1, T2, and T2ClinCheck: Henry’s angle (HA), mesiobuccal-expansion (MBE), distobuccal-expansion (DBE), mesiobuccal-sagittal (MBS), and distobuccal-sagittal (DBS). A paired t-test was used to compare T2-T1 and T2ClinCheck-T2. The T2-T1 shows a distal-rotation (difference −6.3°) with an expansion of 2.2 mm for MBE and 1.5 mm for DBE. At T2, the mesiobuccal cusps show a distal movement of 1.0 mm and the distobuccal cusps of 0.9 mm. The HA’s T2ClinCheck-T2 difference is −4.2°. In the sagittal plane, the difference is 0.9 mm for the MBS and 0.7 mm for the DBS. The expansion showed the highest predictability (60% HA, 52.6% MBS, and 56.25% DBS). The CA effectively produces an arch expansion and upper molars’ distal rotation. Upper molar derotation provides a 1 mm of gain in arch perimeter and occlusal improvement

Substrate preparation for Agaricus bisporus cultivation

ABSTRACT: Mushroom cultivation needs a selected organic substrate obtained during a composting process which is, in some aspects, quite different from the classical one. The aim is to analyse chemical and physical aspects of a composting process for mushroom cultivation in order to point out the peculiar characteristics, which enable a much faster preparation of the substrate. Raw materials were straw, chicken manure, gypsum and ammonium sulphate. In a very short time (11-13 days) the process led to a well-stabilised biomass, as it was shown by humification indexes, C/N ratio trend, organic carbon oxidation and ammonia nitrogen concentration decrease. In comparison to the classical composting procedure, a lower level of ammonia nitrogen and an organic nitrogen enrichment were present in the compost for mushroom cultivation. In addition, the high level of the substrate moisture, more than 75%, well above the limit normally recommended, has probably favoured the microbial growth rendering the process more efficient and faster

Effects of pendulum appliance versus clear aligners in the vertical dimension during Class II malocclusion treatment: a randomized prospective clinical trial

BACKGROUND: The aim of the present study was to compare the effects on vertical dentoskeletal dimension produced by Pendulum appliance and Clear Aligners in patients with Class II malocclusion. TRIAL DESIGN: This is a prospective two-arm parallel group randomized clinical trial with 1:1 allocation ratio. METHODS: The Pendulum Group (PG) consisted of 20 patients (15F, 5 M) with a mean age of 17.2 ± 4.3 years. The Clear Aligners Group (CAG) comprised 20 patients (13F, 7 M) with a mean age of 17.2 ± 3.2 years. Distalization’s protocol in PG involved the activation of TMA wires till the achievement of Class I molar relationship. A protocol of sequential distalization was applied in the CAG. For each subject lateral cephalograms have been analyzed before treatment (T1) and at the end of the therapy (T2). Descriptive statistics and statistical between-group comparisons (PG vs CAG) were calculated for the craniofacial starting forms at T1 and for the T2–T1 changes. Statistical between-group comparisons for the T2–T1 changes were performed with independent samples t-tests (P < 0.05). RESULTS: The PG showed significantly greater increases in SN^GoGn° when compared with CAG (+ 2.1 and − 0.3 degrees, respectively). Clockwise rotation of the occlusal plane with significantly greater increase of SN^POccl angle was observed in PG (+ 2.8 degrees) when compared with CAG (− 4.2 degrees). The PG revealed a significant increase in the N-Me variable with a mean change of + 4.4 mm compared to the CAG with mean values of − 1.2 mm. The PG showed an increase in the ArGo^GoMe angle (+ 0.7° degrees) compared to the CAG (− 3.4° degrees). The PG showed significantly greater increases in both maxillary and mandibular first molar to palatal plane (+ 1.3 and + 2.1 mm, respectively) when compared with CAG (− 0.9 and − 0.2 mm, respectively). CONCLUSIONS: Upper molar distalization with clear aligners represents a valid alternative to non-extraction treatment of Class II malocclusion, reducing the extrusion of maxillary first molars and improving the management of the occlusal plane and vertical dimension. Trial registration: ClinicalTrials.gov, NCT05298280. Registered 28 March 2022—Retrospectively registered, https://clinicaltrials.gov

Correction to: Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial

In the publication of this article (1) there is an error in the Methods section.https://deepblue.lib.umich.edu/bitstream/2027.42/144777/1/40510_2018_Article_231.pd

Dentoskeletal effects of the bitejumping appliance and the twin-block appliance in the treatment of skeletal class ii malocclusion: A retrospective controlled clinical trial

The current retrospective controlled trial aimed to compare the dentoskeletal effects of the Bite-Jumping (BJ) and the Twin- Block Appliance (TB) in the treatment of skeletal Class II malocclusion. The sample was screened for eligibility criteria including skeletal and dental Class II malocclusion; Cervical Vertebral Maturation at Stage 3 at treatment start, and Func- tional orthopedic treatment with either a TB or BJ appliances. Twenty-three patients treated with TB, and twenty-three treated with BJ were included. Cephalometric data were compared with a control group of 15 untreated subjects retrieved from the American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection. Baseline character- istics were similar between groups. A significant increase for the AO-BO dimension, and a significant decrease in the over- jet, were registered for both study groups respect to controls. TB was more effective than BJ in increasing the mandibu- lar length (Co-Gn), in reducing the ANB angle and changing the SNB angle. The resulting differences between the two groups could be attributed to the different appliances. In conclusion, both appliances demonstrated a clinical efficacy in treating Class II. TB seems therefore better indicated, respect to BJ, in Class II cases with a predominant component of mandibular hypoplasia

Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial

Abstract Background The aim of this pilot randomized controlled trial (RCT) was to evaluate the sagittal mandibular response induced by rapid maxillary expansion (RME) therapy in mixed dentition patients with class II malocclusion, comparing the effects of bonded RME and banded RME with a matched untreated class II control group. Methods This RCT was designed in parallel with an allocation ratio of 1:1:1. The sample consisted of 30 children with a mean age of 8.1 ± 0.6 years who were randomly assigned to three groups: group 1 treated with bonded RME, group 2 treated with banded RME, and group 3 the untreated control group. All patients met the following inclusion criteria: early mixed dentition, class II molar relationship, transverse discrepancy ≥ 4 mm, overjet ≥ 5 mm, and prepubertal skeletal maturity stage (CS1–CS2). The expansion screw was activated one quarter of a turn per day (0.25 mm) until overcorrection was reached. For each subject, lateral cephalograms and plaster casts were obtained before treatment (T1) and after 1 year (T2). A randomization list was created for the group assignment, with an allocation ratio of 1:1:1. The observer who performed all the measurements was blinded to group assignment. The study was single-blinded in regard to statistical analysis. Results RME was effective in the correction of maxillary deficiency. Class II patients treated with both types of RME showed no significant improvement of the anteroposterior relationship of the maxilla and the mandible at both skeletal and occlusal levels. The acrylic splint RME had significant effects on reducing the skeletal vertical dimension and the gonial angle. Conclusions The orthopedic expansion did not affect the sagittal relationship of class II patients treated in the early mixed dentition when compared with the untreated control group. Additional studies with a larger sample are warranted to elucidate individual variations in dento-skeletal mandibular response to the maxillary expansion protocol in class-II-growing patients. Trial registration ClinicalTrials.gov NCT03159962

Light-curing process for clear aligners’ attachment reproduction: comparison between two nanocomposites cured by the auxiliary of a new tool

BACKGROUND: Attachments’ configuration play an important role during Clear Aligner Treatment (CAT) for aligner retention and control of movements planned. The aims were to compare the macroscopic morphology of attachments reproduced with flowable (FNC) and conventional (CNC) composites and the effects on them of two light-guide tips with different dimensions. METHODS: 4 resin casts derived from the initial scan of the same patient were obtained. 10 vestibular attachments were replaced on both upper and lower arches of each model with CNC (Models A, B) and FNC (Models C, D). Each composite was cured by means of the same LED lamp with both regular light-guide (Models A, B) and push and light tool® (Models C, D). The 80 attachments were qualitative analyzed by means of a digital stereo microscope. Surface roughness and waviness measurements were assessed by contact probe surface profiler (TalySurf CLI 2000; Taylor Hobson, Leicester, United Kingdom). Statistical analysis was performed with independent samples t-tests. Significance was established at the P < 0.05 level. RESULTS: Model A showed lower values of surface roughness (Ra − 1.41 µm, Rt − 3.46 µm) and waviness (Wa − 2.36 µm, Wt − 10.95 µm) when compared with Model C. Significant reduction of waviness (Wa − 3.85 µm, Wt − 4.90 µm) was observed on Model B when compared with Model D. Significant increase of roughness and waviness parameters (Ra 3.88 µm, Rt 21.07, Wa 2.89 µm, Wt 14.74 µm) was found when CNC sample (Model A) was cured with regular light-guide tip. Higher values (Ra 2.33 µm, Rt 24.07 µm, Wa 1.67 µm, Wt 20.79 µm) were observed after regular light-guide tips curing on FNC sample (Model C). CONCLUSIONS: CNC resins determine more regular surfaces of attachments profiles. The additional use of a smaller light- guide of the LED push and light tool® allows to improve the macroscopic morphology of the attachments and to maximize light irradiance delivering by enhancing the polymerization process and the integrity of the features during the treatment