Magnetic resonance imaging (MRI) image quality can be severely impaired by artifacts caused by fixed orthodontic retainers. In clinical practice, there is a trend towards using computer-aided design/computer-aided manufacturing (CAD/CAM) retainers. This study aimed to quantify MRI artifacts produced by these novel CAD/CAM retainers. Three CAD/CAM retainers and a stainless-steel retainer (“Twistflex”; clinical reference standard) were scanned in vitro at 3-T MRI using a high-resolution 3D sequence. The artifact diameters and three-dimensional artifact volumes (AV) were determined for all mandibular (AVmand) and maxillary (AVmax) retainers. Moreover, the corresponding ratio of artifact volume to retainer volume (AV/RVmand, AV/RVmax) was calculated. Twistflex caused large artifact volumes (AVmand: 13530 mm3; AVmax: 15642 mm3; AV/RVmand: 2602; AV/RVmax: 2235). By contrast, artifact volumes for CAD/CAM retainers were substantially smaller: whereas artifact volumes for cobalt–chromium retainers were moderate (381 mm3; 394 mm3; 39; 31), grade-5 titanium (110 mm3; 126 mm3; 12; 12) and nickel–titanium (54 mm3; 78 mm3; 12; 14) both produced very small artifact volumes. All CAD/CAM retainers caused substantially smaller volumes of MRI artifacts compared to Twistflex. Grade-5 titanium and nickel–titanium CAD/CAM retainers showed the smallest artifact volumes. CAD/CAM retainers made from titanium or nickel–titanium may not relevantly impair image quality in head/neck and dental MRI. Artifacts caused by cobalt–chromium CAD/CAM retainers may mask nearby dental/periodontal structures. In contrast, the large artifacts caused by Twistflex are likely to severely impair diagnosis of oral and adjacent pathologies.

/pdf/evaluation-of-magnetic-resonance-imaging-artifacts-caused-by-3jqgy6wyi0.pdf

Evaluation of magnetic resonance imaging artifacts caused by fixed orthodontic CAD/CAM retainers-an in vitro study.

Magnetic resonance imaging (MRI) is a widely used diagnostic technique. Patients wearing orthodontic appliances are often requested to remove their appliances, even when the MRI exam involves anatomical areas far from mouth, in order to avoid heating of the metal and detachment of the appliance. The purpose of the present investigation was to measure and compare temperature changes and orthodontic appliances' adhesion to enamel after different MRIs. A total of 220 orthodontic brackets were bonded on bovine incisors and wires with different materials (stainless steel and nickel titanium). Moreover, various sizes (0.014″ and 0.019″ × 0.025″) were engaged. Appliances were submitted to MRI at two different powers (1.5 T and 3 T). The temperatures of brackets and wires were measured before and after MRI. Subsequently, the shear bond strength (SBS) and adhesive remnant index (ARI) scores were recorded. Statistical analysis was performed. After MRI, a significant increase in the temperature was found for both the brackets and wires in some groups, even if the mean temperature increase was clinically insignificant, as the temperature ranged between 0.05 °C and 2.4 °C for brackets and between 0.42 °C and 1.74 °C for wires. The MRI did not condition bracket adhesion in any group. No differences were reported when comparing the 1.5 T with 3 T groups. The ARI Scores were also significantly lower after MRI. The results of the present report show that, under MRI, orthodontic appliances present a low temperature rise and no debonding risk. Therefore, the removal of orthodontic appliance is not recommended routinely, but is suggested only in the case of a void risk or potential interference in image quality.

https://www.mdpi.com/1996-1944/12/23/3971/pdf

Magnetic Resonance Imaging and Its Effects on Metallic Brackets and Wires: Does It Alter the Temperature and Bonding Efficacy of Orthodontic Devices?

Objective: The specific aim of this retrospective cross-sectional study was to assess the efficacy of DynaCleft® as a method of presurgical orthopedics with infants with a unilateral cleft lip and cleft palate who used an oral obturator. Study design: Data was collected from 25 infants all of comparable age diagnosed with a unilateral complete cleft lip and palate. Eight patients used DynaCleft ® and an obturator (Group Alpha) and seventeen patients only had an obturator (Group Beta). Maxillary impression casts were obtained from each patient at the initial clinic visit and at the time of cleft lip repair. Differences in alveolar cleft width were compared between the two groups. Casts were measured twice by one observer using a digital caliper. Results: Group Alpha began treatment on an average age of 24.25 days and Group Beta an average of 15.35 days of age. The average cleft width of Group Alpha was 8.13 mm and after treatment it was 4.59 mm. The average cleft width of Group Beta was 8.09 mm and 6.92 mm...

The Effect of DynaCleft® on Cleft Width in Unilateral Cleft Lip and Palate Patients

The achievement of aesthetic, functional occlusion should not mark the end of the orthodontic intervention. To prevent relapse, retention needs advance planning, and may vary in duration. This review aims to present and comment on the available means of retention. The ever-popular, passive Hawley-like removable appliances are credible in maintaining the desired occlusion. Modifications are the removable appliance Wrap Around, having the labial archwire extending to the premolars; the translucent retainer, Astics, a unique aesthetic Hawley-type device; and the reinforced removable retainer, which features a metallic grid reinforcing the acrylic base. Vacuum-formed retainers are easy to fabricate and are readily prescribed. By contrast, fixed retainers are made of orthodontic wire and composite resin bonded on the lingual or palatal surfaces of the anterior teeth. Patient-related variables need evaluation to select the appropriate retainer, while patients ought to realize the importance of retention and comply with offered guidance. Overall, the orthodontist is responsible for keeping the patient informed on the properties and the duration of retention, even before starting active orthodontic treatment.

/pdf/orthodontic-retainers-a-critical-review-bs566k9s.pdf

Orthodontic Retainers—A Critical Review

Preformed metal crowns are widely used to restore primary and permanent teeth. Children may require magnetic resonance imaging (MRI) for diagnosis and monitoring of diseases in the head and neck region. Metallic objects, in the field of view, may compromise the diagnostic value of an MRI. The impact on the diagnostic quality of an MRI in children who have had preformed metal crowns placed has not been assessed. The aim of this systematic review was to evaluate the impact that PFMCs have on MRI imaging quality and thus the overall diagnostic value. Electronic searches of the following databases were completed: MEDLINE, EMBASE, Cochrane Library, Web of Science and Open Grey. Primary in vivo studies on children who had at least one preformed metal crown placed and required an MRI investigation were to be included. PRISMA guidelines were followed and screening/data extraction was carried out by two independent calibrated reviewers. A total of 7665 articles were identified. After removing duplicates, 7062 were identified for title and abstract screening. Thirty-four articles underwent full-text review, of which none met the inclusion criteria. Most common reasons for exclusion were not placing preformed metal crowns (n = 16) or in vitro studies (n = 12). No in vivo studies were identified to establish the hypothetical impact preformed metal crowns would have on the diagnostic quality of an MRI in the head and neck region. Decision making needs to be guided on a case by case basis. Further high-quality clinical studies are required.

/pdf/the-interaction-and-interference-of-preformed-metal-crowns-5csh58vwpy.pdf

The interaction and interference of preformed metal crowns on magnetic resonance imaging: a scoping review with a systematic methodology

Effects of orthodontic appliances on the diagnostic capability of magnetic resonance imaging in the head and neck region: A systematic review.

Digital workflow in the dental is on the brink of completely replacing the traditional workflow. This opened the frontier for the introduction of intraoral scanners (IOS). In the craniofacial field, IOS has proven its applicability in various procedures with highly promising results. This includes comprehensive diagnosis of patients with orofacial clefts and custom-made treatment planning of challenging cases as well as its use in nasoalveolar molding (NAM) therapy. IOS also opened the horizon to the advanced digital workflow required for appliances design, manufacturing, and virtual surgical planning. IOS offer various advantages that decrease the time, effort for both the patients, their families and care providers. IOS adopt different optical technologies what aim for precise recording of a three-dimensional (3D) object. This chapter aims to provide a comprehensive review of the use of intraoral scanners in the craniofacial field.

/pdf/concepts-and-clinical-applications-of-intraoral-3d-scanning-3hh74u4xia.pdf

Majd Hasanin

Papers

Effects of orthodontic appliances on the diagnostic capability of magnetic resonance imaging in the head and neck region: A systematic review.

Concepts and Clinical Applications of Intraoral 3D Scanning in the Management of Patients with Orofacial Clefts

Genetics of three-dimensional tooth inclination and angulation in orthodontic patients with Class I Occlusion: A cross-sectional study.

Does using mobile applications and social media-based interventions induce beneficial behavioral changes among orthodontic patients?

Activation of fixed labial appliances, briefly at initiation, may reduce masticatory performance and bite force