Dietary habits with high consumption of acidic food can induce in orthodontic patients an increased risk of demineralization lesions around orthodontic brackets and bands. The purpose of the present laboratory study is to assess the in vitro visual efficacy of a biomimetic nano‐hydroxyapatite remineralizing solution in a hypomineralized enamel surface and its effect on adhesion of fixed orthodontic appliances and on enamel microhardness. Intact teeth were demineralized, and subsequently the areas of demineralization were visually recorded using a 0–100 scale. Subsequently, a remineralizing solution (Biorepair® Repair Shock Treatment) was applied for ten minutes once a day/for one week per month for a total remineralizing treatment of 3 months. Visual effects were recorded. Moreover, bond strength was recorded and adhesive remnant index scores were measured for both orthodontic brackets and composite attachments both before demineralization and after demineralization and application of remineralizing solution. Also, Vickers microhardness was measured. All data were submitted to statistical analysis. The application of remineralizing solution induced a significant in vitro reduction of demineralized areas after the first week of application. No significant differences between untreated enamel surfaces and remineralized surfaces were detected after 2 months of remineralizing treatment. Bond strength values were significantly reduced for both brackets and attachments after remineralizing treatment. However, attachments showed higher adhesion values than brackets in both conditions tested. Remineralized enamel showed significantly higher microhardness values than demineralized enamel and lower values than intact enamel.

The aim of the present systematic review was to screen the literature and to describe current applications of augmented reality. The protocol design was structured according to PRISMA-P guidelines and registered in PROSPERO. A review of the following databases was carried out: Medline, Ovid, Embase, Cochrane Library, Google Scholar and the Gray literature. Data was extracted, summarized and collected for qualitative analysis and evaluated for individual risk of bias (R.O.B.) assessment, by two independent examiners. Collected data included: year of publishing, journal with reviewing system and impact factor, study design, sample size, target of the study, hardware(s) and software(s) used or custom developed, primary outcomes, field of interest and quantification of the displacement error and timing measurements, when available. Qualitative evidence synthesis refers to SPIDER. From a primary research of 17,652 articles, 33 were considered in the review for qualitative synthesis. 16 among selected articles were eligible for quantitative synthesis of heterogenous data, 12 out of 13 judged the precision at least as acceptable, while 3 out of 6 described an increase in operation timing of about 1 h. 60% (n = 20) of selected studies refers to a camera-display augmented reality system while 21% (n = 7) refers to a head-mounted system. The software proposed in the articles were self-developed by 7 authors while the majority proposed commercially available ones. The applications proposed for augmented reality are: Oral and maxillo-facial surgery (OMS) in 21 studies, restorative dentistry in 5 studies, educational purposes in 4 studies and orthodontics in 1 study. The majority of the studies were carried on phantoms (51%) and those on patients were 11 (33%). On the base of literature the current development is still insufficient for full validation process, however independent sources of customized software for augmented reality seems promising to help routinely procedures, complicate or specific interventions, education and learning. Oral and maxillofacial area is predominant, the results in precision are promising, while timing is still very controversial since some authors describe longer preparation time when using augmented reality up to 60 min while others describe a reduced operating time of 50/100%. The following systematic review was registered in PROSPERO with RN: CRD42019120058.

Objective: Since the introduction of cone-beam computed tomography (CBCT) in dentistry, this technology has enabled distortion-free three-dimensional cephalometric analysis for orthodontic and orthognathic surgery diagnosis. However, CBCT is associated with significantly higher radiation exposure than traditional routine bidimensional examinations for orthodontic diagnosis, although low-dose protocols have markedly reduced radiation exposure over time. The objective of this preliminary feasibility study is to compare the accuracy and diagnostic capabilities of an already-validated three-dimensional cephalometric analysis on CBCT to those of an analysis on 3-T magnetic resonance imaging (3T-MRI) to assess whether the latter can deliver a comparable quality of information while avoiding radiation exposure. Materials and methods: In order to test the feasibility of three-dimensional cephalometry on 3T-MRI, 18 subjects (4 male; 14 female) with mean age 37.8 ± SD 10.2, who had undergone both maxillofacial CBCT and maxillofacial 3T-MRI for various purposes within 1 month, were selected from the archive of the Department of Dentistry and Maxillofacial Surgery of Fondazione Ospedale Policlinico Maggiore, IRCCS, Milano, Italy. A three-dimensional cephalometric analysis composed of ten midsagittal and four bilateral landmarks and 24 measurements (11 angular, 13 linear) was performed on both scans using Mimics Research® v. 17.0 (NV, Technologielaan 15, 3001 Leuven, Belgium). Cephalometric analysis was performed twice by two independent orthodontists for each scan, and each orthodontist repeated the measurements 3 weeks later. Statistical analysis was performed with SPSS® 20.00 for Windows (IBM® Corporation, Sommers, NY, USA). A Bland-Altman test for each cephalometric value was performed to assess the agreement between the procedures. The intraclass correlation coefficient (ICC) was used to assess interobserver and intraobserver reliability. The coefficient of variation was used to evaluate precision. Results: Both procedures showed good reliability, with mean intraobserver ICCs of 0.977/0.971 for CBCT and 0.881/0.912 for MRI. The average interobserver ICCs were 0.965 for CBCT and 0.833 for MRI. A Bland-Altman analysis for the cephalometric tracing revealed a similar range of agreement between the two modalities; the bias range (mean ± SD) was − 0.25–0.66 mm (0.174 ± 0.31) for distances and − 0.41–0.54° (0.12 ± 0.33) for angles. Conclusions: Within the main limitation of this pilot study, that is, the small sample, it is possible to state that cephalometric measurements on 3T-MRI seem to possess adequate reliability and repeatability and that they show satisfying agreement with values measured on CBCTs. An MRI examination does not expose patients to ionizing radiation and could provide an alternative to CBCT for three-dimensional cephalometrics in the future.

The aim is to evaluate changes in the volume of the upper airways before and after slow maxillary expansion (SME) obtained with the flexible properties of a nickel titanium leaf spring and rapid maxillary expansion (RME) with a conventional Hyrax appliance in growing patients. The records of 1200 orthodontic patients undergoing maxillary expansion from 2018 to 2019 were analyzed; among these pre and post treatment CBCT scans of 22 patients (mean age 8.2 ± 0.6 years old) treated by SME were compared with those obtained from 22 patients (mean age 8.1 ± 0.7 years old) treated by RME banded on the second primary molars. The following inclusion criteria were used: Maxillary transverse constriction, good general health, and no previous orthodontic treatment. Volumes of nasal cavity (NCavV), nasopharynx (NsPxV), and right and left maxillary sinuses (MSV) were calculated with ITK-SNAP. Shapiro–Wilk test revealed a normal distribution of data in each group. Paired t-test was used for within-group comparisons and independent t-test for between-group comparisons. Statistically significant increases occurred in NCavV, NsPxV, and MSVs after treatment with both appliances. No statistically significant difference between the appliances occurred in NCavV, NsPxV, and MSVs. Method error was considered negligible (mean intra-operator and inter-operator intraclass correlation coefficient were 0.928 and 0.911, respectively). It appears that both appliances produce similar effects on the different segments of the upper airway tract.

The Palatal Rugae are considered a useful human identification marker for both orthodontists and forensic personnel. The principal aim of the present study was to evaluate the stability of palatal rugae with a 3D-3D superimposition procedure following Slow Maxillary Expansion (SME), in order to assess whether they kept their uniqueness and validity for human identification, even after a specific dental treatment. For this purpose, a sample of 27 digital dental models - belonging to growing patients (13 males and 14 females), aged between 8.5 and 15 years, who underwent SME therapy - was retrospectively studied and compared with a control group of 27 untreated subjects - (13 males and 14 females). Digital dental models were obtained pre-treatment and at device removal; both were processed by means of an intraoral scanner. A superimposition procedure was thus performed to reach the minimum point-to-point distance between two models of palatal rugae. Intra- and inter-observer differences were statistically analyzed by paired Wilcoxon test and Intra-class Correlation coefficient (ICC), showing values larger than 0.93. There was no difference in Root-Mean-Square (RMS) values between untreated control subjects and subjects treated with Leaf Expander (p = 0.062). A RMS value of 0.43 was the threshold to distinguish the pooled group (“Untreated” and “Leaf”) from any mismatch. According to the obtained results, this study failed to reject the null hypothesis and presented no differences between the RMS values of the Test group and the RMS values of the untreated control group. This work highlighted the usefulness of 3D superimposition procedure for purposes of human identification, in subjects undergoing dental treatment. However, keeping in sight the forensic use of this technique as a helpful probation element in court, further studies should be performed to confirm these findings.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus was discovered in China in late 2019 and subsequently triggered a global pandemic. Dentists, like many other health professionals, are at an increased risk of contracting the virus as they work in close proximity to patients, especially when performing aerosol-generating procedures. Thus, in order for dentists to protect themselves and their patients, it is recommended that practitioners wear filtering facepiece 2 (FFP2) respirators. The prolonged use of these FFP2 respirators has been linked to several side effects. The aim of this paper is to assess the perceived experience associated with N95/FFP2 respirators based on the available literature and data collected through an online survey completed by Italian dental professionals. Articles were included up to May 2020 and literature searches were conducted through The National Library of Medicine, Cochrane Central Register of Controlled Trials, and Embase databases. The search terms included COVID-19, respirators, masks, and discomfort. An online survey was administered to 256 Italian dentists. The results from this survey were in agreement with the available literature. The findings concurred that the prolonged use of respirators was associated with headaches (47.5%), severe exertion and discomfort (50.8%), moderate concentration problems (54.3%), moderate breathing difficulties (63.5%), and consequently, an impaired work ability (85.5%). These findings were not influenced by the number of hours spent wearing the respirator. Despite several side effects, FFP2 respirators are fundamental in protecting dentists and their importance was acknowledged.