Assessing mandibular body changes in growing subjects: a comparison of CBCT and reconstructed lateral cephalogram measurements

The aim of this study is to compare cone-beam computed tomography (CBCT) and bi-dimensional reconstructed lateral cephalograms (RLCs) in assessing mandibular body length and growth and to evaluate how mandibular reshaping influences the error in measuring mandibular body growth in bi-dimensional radiographs. Twenty-five patients with two CBCT scans taken at a mean distance of 2.21\u2009\ub1\u20090.5 years were selected. The following measurements were performed: right and left mandibular body length at each point in time, mandibular growth, inter-gonial distance and mandibular symphyseal angle. From each CBCT, an RLC was obtained, and mandibular body length and growth were measured. Data analysis revealed a statistically and clinically significant difference in CBCT and RLC regarding the mandibular length of each patient at each point in time. However, mandibular growth was almost identical. A linear regression was performed to predict growth distortion between RLCs and CBCT depending on the ratio between transverse and sagittal mandibular growth. The expected maximum and minimum distortion, however, appeared not to be significant. In fact, a second linear regression model and a Bland-Altman test revealed a strong correlation between measurements of average mandibular body growth by CBCT and RLCs. As the same distortion occurs in the first and second RLCs, bi-dimensional radiographs remain the method of choice in evaluating mandibular body growth

Hyrax versus transverse sagittal maxillary expander: An assessment of arch changes on dental casts: A retrospective study

Objective: The aim of this study was to compare arch changes before and after maxillary expansion with Transverse Maxillary Sagittal Expander (TSME) and Hyrax Palatal Expander (HPE), in growing patients with diagnosis of maxillary hypoplasia. Materials and methods: The sample consisted of 40 patients\u2019 records (20 males 20 females mean age 9.2 \ub1 2.6 years) were selected from the archive of the Orthodontic Department of the University of Milan, Italy. Patients were randomly divided in two groups: patients in group 1 were treated with HPE as they presented only transverse deficiency of the maxilla and in group 2 were treated with TSME. Plaster models have been measured with a Verniere caliper to evaluate the differences in maxillary expansion of the two devices. Measurements were performed on casts poured from impressions taken before appliance bonding (T0), immediately after appliance debonding (T1) and at 6 months follow-up (T2). The variations in the following distances have been considered: inter-molar distance, inter-canine distance, palatal depth, palatal length and arch circumference. Shapiro-Wilk test was performed to assess normality distribution. ANOVA for repeated measures with multiple paired t-test for pairwise comparisons and its non-parametric equivalent Friedman's test with multiple Wilcoxon tests for pairwise comparisons were performed to evaluate changes in time of each variable in each group. Between groups comparisons were performed for each variable at each observing time using independent t-test or Mann-Whitney test. Significance level was set at p < 0,05. Results: Both the Friedman test and the rm-ANOVA test and their respective post-hoc show that within both groups the respective variables have a statistically significant increase between T0 and T1 (p < 0,05) and a slight decrease between T1 and T2 (p < 0,05) that is not clinically relevant remaining always T2 greater than T0 in a statistically and clinically relevant way (p < 0,05). The analysis between the differences of the measurements at different timing measured by the Mann-Whitney test shows that for all the variables there is no statistically significant difference between the 2 devices (p < 0,05), except for the perimeter of the arch and the length of the palate; in this case it appeared that the TSME is better statistically (p < 0,05). Conclusions: The study has shown that RPE and TSME can achieve similar results in transversal palatal expansion. Differences have been found in the palatal length and in the arch perimeter where TSME seems to be more efficient

Available Technologies, Applications and Benefits of Teleorthodontics. A Literature Review and Possible Applications during the COVID-19 Pandemic

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

Comparison of a tridimensional cephalometric analysis performed on 3T-MRI compared with CBCT : a pilot study in adults

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\u2009\ub1\u2009SD 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\uae 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\uae 20.00 for Windows (IBM\uae 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\u2009\ub1\u2009SD) was -\u20090.25-0.66\u2009mm (0.174\u2009\ub1\u20090.31) for distances and -\u20090.41-0.54\ub0 (0.12\u2009\ub1\u20090.33) 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

Isolation and characterization of buccal fat pad and dental pulp mscs from the same donor

Mesenchymal stem cells (MSCs) can be harvested from different sites in the oral cavity, representing a reservoir of cells useful for regenerative purposes. As direct comparisons between at least two types of MSCs deriving from the same patient are surprisingly rare in scientific literature, we isolated and investigated the osteoinductive potential of dental pulp stem cells (DPSCs) and buccal fat pad stem cells (BFPSCs). MSCs were isolated from the third molar dental pulp and buccal fat pads of 12 patients. The number of viable cells was quantified through manual count. Proliferation and osteodifferentiation assays, flow cytometry analysis of cell phenotypes, and osteocalcin release in vitro were performed. The isolation of BFPSCs and DPSCs was successful in 7 out of 12 (58%) and 3 out of 12 (25%) of retrieved samples, respectively. The yield of cells expressing typical stem cell markers and the level of proliferation were higher in BFPSCs than in DPSCs. Both BFP-SCs and DPSCs differentiated into osteoblast-like cells and were able to release a mineralized matrix. The release of osteocalcin, albeit greater for BFPSCs, did not show any significant difference between BFPSCs and DPSCs. The yield of MSCs depends on their site of origin as well as on the protocol adopted for their isolation. Our data show that BFP is a valuable source for the derivation of MSCs that can be used for regenerative treatments

Gelechiidae Moths Are Capable of Chemically Dissolving the Pollen of Their Host Plants: First Documented Sporopollenin Breakdown by an Animal

Background: Many insects feed on pollen surface lipids and contents accessible through the germination pores. Pollen walls, however, are not broken down because they consist of sporopollenin and are highly resistant to physical and enzymatic damage. Here we report that certain Microlepidoptera chemically dissolve pollen grains with exudates from their mouthparts. Methodology/Principal Findings: Field observations and experiments in tropical China revealed that two species of Deltophora (Gelechioidea) are the exclusive pollinators of two species of Phyllanthus (Phyllanthaceae) on which their larvae develop and from which the adults take pollen and nectar. DNA sequences placed the moths and plants phylogenetically and confirmed that larvae were those of the pollinating moths; molecular clock dating suggests that the moth clade is younger than the plant clade. Captive moths with pollen on their mouthparts after 2-3 days of starvation no longer carried intact grains, and SEM photographs showed exine fragments on their proboscises. GC-MS revealed cis-b-ocimene as the dominant volatile in leaves and flowers, but GC-MS analyses of proboscis extracts failed to reveal an obvious sporopollenindissolving compound. A candidate is ethanolamine, which occurs in insect hemolymphs and is used to dissolve sporopollenin by palynologists. Conclusions/Significance: This is the first report of any insect and indeed any animal chemically dissolving pollen

Three-dimensional evaluation of the maxillary sinus in patients with different skeletal classes and cranio-maxillary relationships assessed with cone beam computed tomography

The objective was to evaluate the relationship between the dimensions of the maxillary sinuses (MSs) and various cephalometric parameters. MS volume (MSV), MS surface (MSS), linear maximum depth (LMD), linear maximum width (LMW), and linear maximum height (LMH) were calculated on CBCT scans of 99 adults. Two sets of two-way (ANOVA) assessed the influence respectively of ANB and SNA angles and of the gender on MS dimensions. Pearson’s correlation was calculated between MS dimensions and different cephalometric variables. Reliability and accuracy of the proposed method was tested with intra-operator and inter-operator intraclass correlation coefficient (ICC). Two-way ANOVA showed no statistically significant difference in MSV, MSS and LMH between ANB groups, whilst males were associated with bigger sinuses. LMW showed statistically significant difference in both ANB and gender groups. LMD showed no statistically significant difference. The second Two-way ANOVA showed significantly larger MSV, MSS and LMD in patients with increased or reduced SNA angle but not between genders. LMW and LMH also showed a significant difference between genders. All linear measurements showed a significant interaction of the two factors. The intra-observer and inter-observer ICC scored high for all the tested measurements. MSV and MSS showed a positive correlation with S-N, PNS-A, S-Go, N-Me, N-Ans and the distance between Mx points. LMW had a negative correlation with Ba-S-N angle and N-Me, LMH with Ba-S-N angle, S-Go and Mx r-Mx l and LMD with N-Me and N-ANS. LMW had a positive correlation with Mx r-Mx l, LMH with S-N, S-N^Ans-Pns, N-Me, N-Ans and LMD with S-N, Ba-S-N, PNS-A, S-Go and distance between Mx points. In conclusion, MSV and MSS did not differ between the three skeletal classes, males showed significantly larger MS than in females. Concerning the influence of the cranio-maxillary relationship (SNA) and gender on MS dimension, subjects with a retrusion (SNA < 80°) or protusion (SNA > 84°) of the maxillary alveolar bone had larger MSV, MSS, LMW, LMH and LMD than subjects with a normal cranio-maxillary relationship (SNA 82 ± 2°). A statistically significant high positive correlation was observed between S-N, Pns-A, S-Go, Mx-R/Mx-r and MS dimension. Further studies that evaluate similar outcomes in different races may be able to enrich our knowledge on this topic

Relationship between Breastfeeding and Malocclusion : a Systematic Review of the Literature

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