Reconstruction of bony defects is challenging when conventional grafting methods are used because of their intrinsic limitations (biological cost and/or biological properties). Bone regeneration techniques are rapidly evolving since the introduction of three-dimensional (3D) bioprinting. Bone tissue engineering is a branch of regenerative medicine that aims to find new solutions to treat bone defects, which can be repaired by 3D printed living tissues. Its aim is to overcome the limitations of conventional treatment options by improving osteoinduction and osteoconduction. Several techniques of bone bioprinting have been developed: inkjet, extrusion, and light-based 3D printers are nowadays available. Bioinks, i.e., the printing materials, also presented an evolution over the years. It seems that these new technologies might be extremely promising for bone regeneration. The purpose of the present review is to give a comprehensive summary of the past, the present, and future developments of bone bioprinting and bioinks, focusing the attention on crucial aspects of bone bioprinting such as selecting cell sources and attaining a viable vascularization within the newly printed bone. The main bioprinters currently available on the market and their characteristics have been taken into consideration, as well.

Background: COVID-2019 spread rapidly throughout the world from China. This infection is highly contagiousness, has a high morbidity, and is capable of evolving into a potentially lethal form of interstitial pneumonia. Numerous countries shut-down various activities that were considered “not essential.” Dental treatment was in this category and, at the time of writing, only non-deferrable emergencies are still allowed in many countries. Therefore, follow-up visits of ongoing active therapies (e.g., orthodontic treatment) must be handled taking special precautions. This literature review aims at reducing in-office appointments by providing an overview of the technologies available and their reliability in the long-distance monitoring of patients, i.e., teledentistry. Methods: A literature review was made according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines. Randomized clinical trials, cross sectional, observational, and case-control studies were evaluated with the Mixed Methods Appraisal Tool for quality assessment and study limitations. Results: A primary search found 80 articles, 69/80 were excluded as non-relevant on the basis of: the abstract, title, study design, bias, and/or lack of relevance. Twelve articles were included in the qualitative analysis. Conclusions: Teleorthodontics can manage most emergencies, reassuring and following patients remotely. The aim set by dental teleassistance was met as it reduced patients’ office visits whilst maintaining regular monitoring, without compromising the results. Although our preliminary findings should be further investigated to objectively evaluate the efficacy, cost-effectiveness, and long-term results, we are confident that teleassistance in orthodontics will have a role to play in the near future.

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.

Background: Cephalometric analysis is traditionally performed on skull lateral teleradiographs for orthodontic diagnosis and treatment planning. However, the skull flattened over a 2D film presents projection distortions and superimpositions to various extents depending on landmarks relative position. When a CBCT scan is indicated for mixed reasons, cephalometric assessments can be performed directly on CBCT scans with a distortion free procedure. The aim of the present study is to compare these two methods for orthodontic cephalometry. Methods: 114 CBCTs were selected, reconstructed lateral cephalometries were obtained by lateral radiographic projection of the entire volume from the right and left sides. 2D and 3D cephalometric tracings were performed. Since paired t-tests between left and right-side measurements found no statistically significant differences, mean values between sides were considered for both 2D and 3D values. The following measurements were evaluated: PNS-A; S-N; N-Me; N-ANS; ANS-Me; Go-Me; Go-S; Go-Co; SNA, SNB, ANB; BaŜN; S-N^PNS-ANS; PNS-ANS^Go-Me; S-N^Go-Me. Intraclass correlation coefficients, paired t-test, correlation coefficient and Bland–Altman analysis were performed to compare these techniques. Results: The values of intra- and inter-rater ICC showed excellent repeatability and reliability: the average (± SD) intraobserver ICCs were 0.98 (± 0.01) and 0.97(± 0.01) for CBCT and RLCs, respectively; Inter-rater reliability resulted in an average ICC (± SD) of 0.98 (± 0.01) for CBCT and 0.94 (± 0.03) for RLC. The paired t-tests between CBCT and reconstructed lateral cephalograms revealed that Go-Me, Go-S, PNS-ANS^Go-Me and S-N^Go-Me measurements were statistically different between the two modalities. All the evaluated sets of measurements showed strong positive correlation; the bias and ranges for the 95% Limits of Agreement showed higher levels of agreement between the two modalities for unpaired measurements with respect to bilateral ones. Conclusion: The cephalometric measurements laying on the mid-sagittal plane can be evaluated on CBCT and used for orthodontic diagnosis as they do not show statistically significant differences with those measured on 2D lateral cephalograms. For measurements that are not in the mid-sagittal plane, the future development of specific algorithms for distortion correction could help clinicians deduct all the information needed for orthodontic diagnosis from the CBCT scan.

Background: The purpose of this systematic review was to analyze the available literature about the influence of breastfeeding in primary and mixed dentition on different types of malocclusions. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines were used to perform the present review. The following electronic databases were searched: Pubmed, Evidence-Based Medicine Reviews (EBMR), Embase, Cochrane Library, Medline, Web of Science and Ovid. Results: A primary research found a total of 279 articles. Two more papers were also considered from the gray literature. Two hundred sixty-three articles were excluded as they were deemed irrelevant on the basis of: duplicates, title, abstract, methods and/or irrelevant contents. Eighteen papers were selected and included in the qualitative analysis. Conclusions: breastfeeding is a positive factor that seems to reduce the incidence of posterior crossbite, skeletal class II and distoclusion in primary and mixed dentition. A sort of positive relationship between months of breastfeeding and risk reduction seems to exist. More longitudinal research is needed to avoid bias in the results, with data collected prospectively on the months of exclusive breastfeeding, by means of specific questionnaires and successive clinical evaluation of the occlusal condition at the primary dentition, mixed dentition and permanent dentition stages.

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.