The treatment effects of maxillary asymmetric mechanics with the use of the mesial-distalslider: A retrospective study.

INTRODUCTION: This study had 2 objectives: (1) to evaluate the clinical efficacy of the Mesial-Distalslider (MD) appliance when used for simultaneous maxillary molar mesialization and distalization in patients with a maxillary asymmetrical relationship and (2) to compare the outcomes with those achieved using the unilateral Mesialslider (UM) appliance. METHODS: The sample included 40 subjects (25 females and 15 males) with a mean age of 22 years (range, 8-55 years). The patients were divided into 2 groups: 20 patients treated with an MD appliance (group 1) and a group of 20 patients treated with a UM appliance (group 2). Superimposition of digital dental models using regions of interest on the palate was performed to evaluate the 3-dimensional molar movements, the proclination or retroclination of the maxillary incisors, and the displacement of the maxillary midline. RESULTS: At the end of the treatment, the MD group's total movements were 4.5 ± 2.2 mm (sagittal), -0.4 ± 2.4 mm (transverse), and 0.3 ± 0.9 mm (vertical) along the mesialization side and -2.4 ± 1.7 mm (sagittal), -0.5 ± 1.5 mm (transverse), and 0.2 ± 1.4 (vertical) along the distalization side. UM group total movements were 5.5 ± 3.6 mm (sagittal), -0.4 ± 2.7 mm (transverse), and 0.1 ± 2.0 mm (vertical). Incisor displacements were minimal. No statistically significant differences were found between the MD and UM groups for all the parameters. CONCLUSIONS: The use of the MD enables controlled movements in the sagittal direction with negligible dental side effects in the other planes (transverse and vertical). Furthermore, it facilitates asymmetrical movements simultaneously in the desired direction without the patient's compliance and provides good anchorage control.

Upper Midline Correction Using the Mesial-Distalslider.

AIM: The purpose of the present study is the three-dimensional (3D) analysis of molar and incisor movements that occur during the correction of the upper midline deviation by using the Mesial-Distalslider appliance. MATERIALS AND METHODS: A total of 20 consecutive patients (12 women and 8 men; mean age 19.6 ± 11.1 years) were selected from the Orthodontic Department of Heinrich-Heine University of Düsseldorf. To correct the upper midline deviation (>2 mm), the patients were treated with asymmetric mechanics (mesialization on one side and distalization on the contralateral side) with the aid of Mesial-Distalslider. Dental casts were taken for each patient before (T0) and after the treatment (T1). The casts were 3D digitized and the models were superimposed on the palatal anterior region. Three-dimensional molar movements and sagittal incisor movements (proclination and retroclination) were assessed for T0 and T1. RESULTS: At the end of the treatment, the total movements of the molars resulted in 4.5 ± 2.2 mm (antero-posterior direction), -0.4 ± 2.4 mm (transverse direction) and 0.3 ± 0.9 mm (vertical direction) on the mesialization side, and -2.4 ± 1.7 mm (antero-posterior direction), -0.5 ± 1.5 mm (transverse direction) and 0.2 ± 1.4 mm (vertical direction) on the distalization side. Incisor displacement was 0.9 mm ± 1.7 (mesialization side) and 0.6 mm ± 0.7 (distalization side). CONCLUSION: The Mesial-Distalslider appliance could be considered a valuable tool in orthodontic treatment for upper midline correction. Within the limits of a retrospective study, asymmetric molar movements appeared possible without clinically relevant anchorage loss.

An evaluation of the Invisalign® Aligner Technique and consideration of the force system: a systematic review.

OBJECTIVE: Since its introduction 25 years ago, the Invisalign® system has undergone multiple digital and biomechanical evolutions and its effectiveness is often compared to traditional systems without considering the many differences which characterize them. The main aim of this systematic review is to look at the literature dealing with studies on teeth movements using the Invisalign® system and the management of these movements through digital planning and artificial intelligence. MATERIALS AND METHODS: The following electronic databases were searched: MEDLINE, Embase, the Cochrane Oral Health Group's Trials Register, and CENTRAL. Unpublished studies were searched on ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. RESULTS: Twenty-four studies (15 retrospective, 5 prospective, 2 pilot, and 2 case-control) were included. The results of the analysis carried out on the available literature show that the Invisalign® system is recognized to be a valid alternative to conventional orthodontic treatment in no-extraction cases. The results are influenced by the methods for assessing the effectiveness of this technique and by the comparison bias of the traditional system with the innovative digital system. CONCLUSIONS: Since the introduction of SmartForce and SmartTrack material, the efficacy of the treatment has improved. There is still a shortage of high-quality evidence concerning the treatment modality. In order to make the treatment with the aligners more efficient, a correct management of the ClinCheck® software and a proper use of the biomechanics are necessary. The aligned force-driven system should be taken into account when developing the digital planning.

Intercepting of Class III Malocclusion with a Novel Mechanism Built on the Orthopaedic Appliance: A Case Report.

AIM: The following case report aims to show a novel orthopaedic appliance to reduce the side effects of the orthopaedic Class III treatment through the use of two acrylic splints combined with a PowerScope device. MATERIALS AND METHODS: This case report describes the treatment of a 6-year-old patient with a skeletal Class III relationship with a maxillary deficiency and a severe hyperdivergency. The patient underwent a sagittal orthopaedic treatment with a PowerScope device for 12 months. The retention period lasted 4 months. RESULTS: The response of the craniofacial complex to the active orthopaedic treatment of the Class III malocclusion with the PowerScope™ device splints consisted of significant changes in maxillary growth and position. Both angular and linear sagittal measurements of the maxilla showed improvements during active treatment, respectively, of 0.6° and 1.2 mm (SNA from 75.8° to 76.4°; maxillary length from 38.8 mm to 40 mm). These effects allowed for a highly significant improvement in the maxillomandibular skeletal relationships. ANB improved by 1.6° and Wits appraisal by 4 mm. Using this appliance in a hyperdivergent patient, we obtained a vertical control of the mandible with a SN/Go-Gn stable value at 40° and a significant improvement of the ANS-PNS/GoGn angle from 30° to 28°. CONCLUSION: The Class III orthopaedic treatment with the PowerScope™ telescopic and NiTi spring device mounted on the upper and lower resin splints in a Class III correction offered good vertical control during the early orthopaedic treatment by improving the skeletal discrepancy and controlling the hyperdivergency, which is one of the most difficult factors to control in Class III malocclusions.

Experience and Prevalence of Dental Caries in Migrant and Nonmigrant Low-SES Families' Children Aged 3 to 5 Years in Italy.

Dental caries is a public health problem in children and is more prevalent in low-socioeconomic-status groups. The aim of this study is to assess the association between migrant families and the prevalence of caries among young children in Italy. This is a cross-sectional study. In the age range of 3 to 5 years, a total of 266 migrant children and 301 nonmigrant children were examined in three Italian charity dental centers. All children had families with low SES. The dmft was determined by intraoral examination performed by six pediatric dentist specialists to assess their dental health. In this study, the prevalence of caries (71%) and the mean dmft (3.68; SD: 1.52) of migrant children were statistically significantly higher than the percentage (52%) and the mean dmft of the nonmigrant control group (3.10; SD: 1.65) with no differences between genders. For the migrant children, the mean (0.49; SD: 0.32) of restorations (filled teeth) was statistically significantly lower than that of nonmigrant children (1.20; SD: 0.48). This study highlights that dmft values and the prevalence of caries are higher in migrant children than in nonmigrant children. In addition, the control group shows a higher level of dental caries than the national mean.

Mechanical Evaluation of the Stability of One or Two Miniscrews under Loading on Synthetic Bone.

The aim of the present study was to evaluate the primary stability of a two-miniscrew system inserted into a synthetic bone and to compare the system with the traditional one. Forty-five bi-layered polyurethane blocks were used to simulate maxillary cancellous and cortical bone densities. Samples were randomly assigned to three groups-one-miniscrew system (Group A, N = 23), two-miniscrew system (Group B, N = 22) and archwire-only (Group C, N = 10). A total of 67 new miniscrews were subdivided into Group A (23 singles) and Group B (22 couples). 30 mm of 19″ × 25″ archwires were tied to the miniscrew. The load was applied perpendicularly to the archwire. Maximum Load Value (MLV), Yield Load (YL) and Loosening Load (LL) were recorded for each group. The YL of Group B and C had a mean value respectively of 4.189 ± 0.390 N and 3.652 ± 0.064 N. The MLV of Group A, B and C had a mean value respectively of 1.871 ± 0.318N, of 4.843 ± 0.515 N and 4.150 ± 0.086 N. The LL of Group A and B had a mean value respectively of 1.871 ± 0.318 N and of 2.294 ± 0.333 N. A two- temporary anchorage device (TAD) system is on average stiffer than a one-TAD system under orthodontic loading.

Accuracy of interproximal enamel reduction during clear aligner treatment.

AIM: The aim of the present study was to compare the accuracy of the actual space obtained through interproximal enamel reduction (IPR) compared to the amount of IPR planned through the digital setup during clear aligner treatment (CAT). MATERIALS AND METHODS: A total of 10 clinicians were randomly recruited using the Doctor Locator by Align Technology (California). For each clinician, four consecutive patients treated with CAT and manual stripping were selected for a total of 40 subjects and 80 dental arches. For each patient, the amount of planned IPR and the amount of actual IPR performed were recorded. Each arch was considered individually. For each arch, the mesio-distal tooth measurements were obtained from second to second premolars. RESULTS: No systematic measurement errors were identified. In 25 cases, stripping was planned and performed in both arches; in 4 cases only in the upper arch and in the remaining 7 cases only in the lower arch. The difference between planned IPR and performed IPR was on average 0.55 mm (SD, 0.67; P = 0.022) in the upper arch and 0.82 mm (SD, 0.84; P = 0.026) in the lower arch. The accuracy of IPR in the upper arch was estimated to be 44.95% for the upper arch and 37.02% for the lower arch. CONCLUSION: Overall, this study showed that the amount of enamel removed in vivo did not correspond with the amount of IPR planned. In most cases, the performed IPR amount was lower than planned. When considering the actual amount in millimeter, these differences may not be considered clinically relevant.

Periodontal status of buccally and palatally impacted maxillary canines after surgical-orthodontic treatment with open technique.

This study investigated differences in periodontal health variables between buccally impacted maxillary canines (BIMC) and palatally impacted maxillary canines (PIMC) after surgical-orthodontic treatment with open technique. Nineteen patients were enrolled: 10 with unilateral BIMC (5 men, 5 women; mean age 18.50 ± 1.96 years) and 9 with unilateral PIMC (4 men, 5 women; mean age 19.44 ± 2.40 years). Probing depth and keratinized tissue were recorded 12 months after surgical-orthodontic treatment, and the differences between the 2 sides were analyzed as primary outcomes. In addition, data for BIMC and PIMC were directly compared. In the BIMC group, probing depths were significantly higher for lateral incisors than for the untreated side (P = 0.044), and keratinized tissue values were significantly lower for canines than for the untreated side (P = 0.006). No significant differences were observed in the PIMC group. In BIMC, surgical-orthodontic treatment with open technique resulted in loss of periodontal keratinized tissue in the treated tooth and periodontal attachment loss in adjacent lateral incisors. However, the periodontal status of PIMC was not affected by surgical-orthodontic treatment with open technique.