Diagnosis and rehabilitation of an infant with palatal mucormycosis: A clinical report and systematic literature review

STATEMENT OF PROBLEM

Oral mucormycosis is uncommon in pediatric patients with hematolymphoid diseases. Prosthetic rehabilitation is challenging, and protocols are scarce in the literature.

PURPOSE

The purpose of this clinical report and systematic literature review of case reports and case series was to describe the clinicopathologic aspects of oral mucormycosis and the interim prosthetic rehabilitation of an affected infant.

MATERIAL AND METHODS

The clinical lesions were ulcerative and necrotic with underlying bone exposure that affected the hard palate. The affected area underwent surgical debridement, and histopathologic analysis was performed. A literature search in PubMed/MEDLINE, Embase, Scopus, and Web of Science up to October 2023 was performed.

RESULTS

The histopathological features were consistent with mucormycosis. Topical and systemic antifungals were prescribed. Tooth eruption was insufficient, and an acetate plate without clasp retention, but still with adequate retention, was fabricated. Articulatory, masticatory, and swallowing functions were restored, preventing the passage of food and fluids into the oroantral cavities. Twenty-five articles describing 26 patients with oral mucormycosis related to hematolymphoid disorders affecting the pediatric population were identified. None of the authors of these articles provided information about oral rehabilitation.

CONCLUSIONS

Early diagnosis and treatment are essential to increasing the chances of survival for infants affected by oral mucormycosis. Custom-made rehabilitation should be provided to restore oral function and improve the patient's general health.

Protective Effect of Bovine Milk Extracellular Vesicles on Alveolar Bone Loss

SCOPE

Bovine milk extracellular vesicles (MEVs) have demonstrated therapeutic potential in regulating bone cell activity. However, the outcome of their use on alveolar bone loss has not yet been demonstrated.

METHODS AND RESULTS

This study evaluates the effect of oral administration of MEVs on ovariectomized (OVX) mice. There is a reduced height of the alveolar bone crest in OVX mice by MEVs treatment, but the alveolar bone parameters are not altered. OVX mice are then submitted to a force-induced bone remodeling model by orthodontic tooth movement (OTM). MEVs-treated mice have markedly less bone remodeling movement, unlike the untreated OVX mice. Also, OVX mice treated with MEVs show an increased number of osteoblasts and osteocytes associated with higher sclerostin expression and reduce osteoclasts in the alveolar bone. Although the treatment with MEVs in OVX mice does not show differences in root structure in OTM, few odontoclasts are observed in the dental roots of OVX-treated mice. Compared to untreated mice, maxillary and systemic RANKL/OPG ratios are reduced in OVX mice treated with MEVs.

CONCLUSION

Treatment with MEVs results in positive bone cell balance in the alveolar bone and dental roots, indicating its beneficial potential in treating alveolar bone loss in the nutritional context.

Influence of risedronate on orthodontic tooth movement in rodents: a systematic review and case report

INTRODUCTION

Bisphosphonates have an inhibitory impact on osteoclastic activity, reducing bone resorption. However, the influence of risedronate on tooth movement is not well-defined.

OBJECTIVE

This systematic review assessed the effect of risedronate intake on orthodontic tooth movement. A case report was also provided.

METHODS

Two independent reviewers searched six databases (PubMed, Web of Science, Ovid, Lilacs, Scopus, and Open Grey). The searches were carried out in April/2020, and an update was set in place in June/2023. Therefore, the searches considered a timeline from the databases' inception date until June/2023, with no publication date and/or language restrictions. The clinical question focused on evaluating the orthodontic tooth movement and relapse movement (Outcome) in animals (Population) exposed to risedronate (Exposure), compared to control groups (Comparison). The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were applied, and the protocol was registered in PROSPERO (CRD42020168581). The risk of bias was determined using the Systematic Review Centre for Laboratory Animal Experimentation protocol (SYRCLE).

RESULTS

Two studies in rats and one in guinea pigs were included in the systematic review. The studies reported a decrease in orthodontic tooth movement, a reduction in the relapse movement, and a reduced number of positive tartrate-resistant acid phosphatase (TRAP) cells, with a significantly reduced number of bone gaps after the administration of risedronate in rats. A case report illustrated the effects of risedronate administration in one patient.

CONCLUSION

Based on the systematic review, risedronate seems to impair orthodontic tooth movement and relapse due to a decrease in bone resorption cells.

Orthodontic treatment during pregnancy, lactation, and postmenopausal period: a questionnaire development

This study aimed to develop and validate a self-administered questionnaire in Brazilian Portuguese to verify the level of knowledge of orthodontists in the care of pregnant, lactating, and postmenopausal women, named "Considerations on Orthodontic Treatment during Pregnancy, Lactation, and Postmenopausal Periods." The development and validation of the questionnaire consisted of the following steps: a) item generation; b) item reduction; c) questionnaire design; and d) validity and reliability tests in a cross-sectional study with 258 orthodontists working in the field from different Brazilian states. A total of 60 orthodontists participated in test-retest over a mean period of 45 days. The preliminary questionnaire consisted of a total of 60 questions. After item reduction, 40 questions were selected for the final version of the questionnaire, with eight questions about pregnant women; six about lactating women; 18 about postmenopausal women, and eight about general knowledge in dentistry. Each item had three response options in the Likert scale format. Face and content validity analysis, reliability assessment through internal consistency (Cronbach's alpha and McDonald's omega), and test-retest reliability through the intraclass correlation coefficient (ICC) and Spearman's correlation coefficient were performed. Face and content validity indicated that the questionnaire was considered valid, objective, and easily understandable. The questionnaire had good internal consistency (Cronbach's alpha = 0.77; McDonald's omega = 0.78) and good test-retest reliability (ICC = 0.71; Spearman's correlation coefficient = 0.51). The questionnaire was considered valid and reliable to assess the level of knowledge of orthodontists in the care of pregnant, lactating, and postmenopausal women.

Kinetics of neutrophil extracellular traps and cytokines in oral mucositis and Candida infection

OBJECTIVE

This study investigated the concentrations of neutrophil extracellular traps (NET) and salivary cytokines (IL-1β, IL-6, IL-8/CXCL8, TNF, and TGF-β1) in patients undergoing chemotherapy and their associations with oral mucositis (OM) and Candida infection.

MATERIALS AND METHODS

This prospective longitudinal study performed at a Brazilian service included 60 adults diagnosed with hematolymphoid diseases. Saliva samples were collected on days D0, D3, D10, and D15. Cytokines were analyzed by ELISA and NET formation by identification of the myeloperoxidase-DNA complex. Oral Candida spp. was cultured.

RESULTS

OM occurred in 43.3% of patients and oral candidiasis in 20%. However, 66% of individuals had positive cultures for C. albicans. Higher concentrations of IL-6, IL-8/CXCL8, and TNF and lower concentrations of TGF-β1 were observed in patients with OM. C. albicans infection contributed to the increase in IL-8/CXCL8, TGF-β1, and TNF. Individuals with OM or with oral candidiasis had significant reductions in NET formation. In contrast, individuals with C. albicans and with concomitant C. albicans and OM exhibited higher NET formation.

CONCLUSION

The kinetics of cytokine levels and NET formation in chemotherapy-induced OM appears to be altered by Candida infection, even in the absence of clinical signs of oral candidiasis.

Bone strength is reduced in a neonatal androgenized rat model

Background

Whether polycystic ovary syndrome (PCOS) affects bone health during a woman's lifespan remains controversial. An androgenized rodent model replicated many metabolic and reproductive features of women with PCOS, and we aimed to use it to investigate the impact of androgens on microarchitecture (by micro-CT), bone mechanical strength, bone formation and resorption markers in rats with intact ovaries (SHAM) who underwent oophorectomy.

Methods

Wistar rats (Rattus norvegicus albinus) were employed for the experiments in this study. The protocol of androgenization consisted of the application of 1.25 mg s.c. testosterone propionate beteween days 2-5 of life, while the controls received the same amount of corn oil s.c. as previously established. Androgenized SHAM rats exhibited chronic anovulation identified by vaginal cytology and a reduction in the proportion of corpus luteum in the ovary in comparison to control SHAM rats. The realization of the ovariectomy or SHAM procedure occurred on Day 100 of life. All groups (n = 8) were followed-up for 180 days to address the study endpoints.

Results

Micro-CT from androgenized female rats (SHAM) showed a divergence between the trabecular and cortical bone profiles. Compared to SHAM controls, these rats had an increase in trabecular bone mass with a diminution in bone resorption C-terminal telopeptide of type 1 collagen (CTX) (p < 0.05), a concomitant decrease in cortical area and thickness in the femur, and a reduction in the strength of the femur on the mechanical test (p < 0.01).

Conclusions

Our results suggest that a reduction in the cortical thickness and cortical area observed in PCOS model rats was associated with a reduced strength of the femur, despite increased trabecular formation. Ovariectomy in the androgenized OVX group limited the progression rate of cortical bone loss, resulting in bone resistance and cortical thickness comparable to those observed in the control OVX group.

Effects of bisphenol A on murine salivary glands and human tumor cell lines

Bisphenol A (BPA) is an endocrine-disrupting chemical with a potential role in endocrine cancers. However, the effects of BPA on the salivary glands have been barely explored. We investigated the impact of in vivo sub-chronic exposure to BPA and its in vitro effects on human salivary gland mucoepidermoid carcinoma cell lines. Male and female mice were exposed to BPA (30 mg/kg/day). Sublingual and submandibular salivary glands from an estrogen-deficiency model were also analyzed. BPA concentration in salivary glands was evaluated by gas chromatography coupled to ion trap mass spectrometry. Immunohistochemical analysis using anti-p63 and anti-α-SMA antibodies was performed on mouse salivary gland tissues. Gene expression of estrogen receptors alpha and beta, P63 and α-SMA was quantified in mouse salivary gland and/or mucoepidermoid (UM-HMC-1 and UM-HMC-3A) cell lines. Cell viability, p63 and Ki-67 immunostaining were evaluated in vitro. BPA disrupted the tissue architecture of the submandibular and sublingual glands, particularly in female mice, and increased the expression of estrogen receptors and p63, effects that were accompanied by significant BPA accumulation in these tissues. Conversely, ovariectomy slightly impacted BPA-induced morphological changes. In vitro, BPA did not affect the proliferation of neoplastic cells, but augmented the expression of p63 and estrogen receptors. The present data highlight a potential harmful effect of BPA on salivary gland tissues, particularly in female mice, and salivary gland tumor cells. Our findings suggest that estrogen-dependent pathways may orchestrate the effects of BPA in salivary glands.

Targeting phosphatidylinositol-3-kinase for inhibiting maxillary bone resorption

Previous studies have suggested a role of phosphatidylinositol-3-kinase gamma (PI3Kγ) in bone remodeling, but the mechanism remains undefined. Here, we explored the contribution of PI3Kγ in the resorption of maxillary bone and dental roots using models of orthodontic tooth movement (OTM), orthodontic-induced inflammatory root resorption, and rapid maxillary expansion (RME). PI3Kγ-deficient mice (PI3Kγ-/- ), mice with loss of PI3Kγ kinase activity (PI3KγKD/KD ) and C57BL/6 mice treated with a PI3Kγ inhibitor (AS605240) and respective controls were used. The maxillary bones of PI3Kγ-/- , PI3KγKD/KD , and C57BL/6 mice treated with AS605240 showed an improvement of bone quality compared to their controls, resulting in reduction of the OTM and RME in all experimental groups. PI3Kγ-/- mice exhibited increased root volume and decreased odontoclasts counts. Consistently, the pharmacological blockade or genetic deletion of PI3K resulted in increased numbers of osteoblasts and reduction in osteoclasts during OTM. There was an augmented expression of Runt-related transcription factor 2 (Runx2) and alkaline phosphatase (Alp), a reduction of interleukin-6 (Il-6), as well as a lack of responsiveness of receptor activator of nuclear factor kappa-Β (Rank) in PI3Kγ-/- and PI3KγKD/KD mice compared to control mice. The maxillary bones of PI3Kγ-/- animals showed reduced p-Akt expression. In vitro, bone marrow cells treated with AS605240 and cells from PI3Kγ-/- mice exhibited significant augment of osteoblast mineralization and less osteoclast differentiation. The PI3Kγ/Akt axis is pivotal for bone remodeling by providing negative and positive signals for the differentiation of osteoclasts and osteoblasts, respectively.

A new way of analyzing tooth movement using universal coordinate system geometry single point superposition in a 3D model

INTRODUCTION

Superposing 3D models is an imminent need. However, current methods rely on marking multiple points on the maxilla and mandible, which could increase point marking and overlapping errors.

OBJECTIVE

This study aimed at developing a method for superimposing 3D models of the maxillary and mandibular arches with Autodesk Inventor® engineering software, using a single universal coordinate system (UCS) point superposition.

METHODS

A total of 104 STL (stereolithography) models of the maxillary and mandibular arches exported from My iTero® platform were retrospectively selected, in which T0 and T1 were the initial and refinement periods, respectively (n=26 per group). The X, Y, and Z coordinates associated with a single point in each arch were inserted into the models with SlicerCMF® software for model orientation. The arch models with UCS registration were transferred to Autodesk Inventor® for superimposition and to measure tooth movements performed during Invisalign® treatment. Arch expansion, intrusion and rotation were analyzed by two examiners. The statistics were performed using intraclass correlation coefficients (ICC), Dahlberg's formula, and t-test (p<0.05).

RESULTS

A reliable method of superimposing 3D digital models using a single UCS point in the maxilla and mandible was developed. ICC showed excellent intra- and inter-examiner correlation (ICC>0.90). A systematic error was not found concerning linear and angular measurements (<1mm and <1.5°, respectively). Digital dental movements could be analyzed, including arch expansion, dental intrusion, and tooth rotation.

CONCLUSIONS

The developed method was proven reliable and reproducible for superimposing 3D models of the maxillary and mandibular arches by using UCS system.

The Effects of NAM on the Symmetry of the Face and Maxillary Arch in Babies With Unilateral Cleft

The study aimed to evaluate the effect of nasoalveolar molding (NAM) therapy through reverse engineering, or its absence, to obtain symmetry of the face and maxillary arch. Twenty-six babies with unilateral cleft lip and palate received treatment with NAM, and 12 babies with unilateral cleft lip and palate without presurgical orthopedics (control group). Patients were molded and photographed in 2-stages: the first month of life (T1/pre) and after the use of NAM/before the cheiloplasty (T2/post). In the digital models, the analyses performed were arch perimeter, arch length, and labial frenulum angle. The photographs allowed us to analyze nasal width, mouth width, columella angle, and nostril area. The results demonstrated that there was an increase in arch perimeter and arch length in control and NAM groups in the T2 period in comparison to T1. Labial frenulum angle was reduced in the NAM group compared to the NAM-T1 and control-T2 periods. Treatment with NAM yielded a reduction in nasal width in the period of T2 compared with T1. Columella angle was enhanced after NAM use in T2 and, was different from control group. The nostril area was reduced in the NAM group in T2 compared with control group. Nasoalveolar molding therapy reduced the labial frenulum angle, contributing to a reduction in the extension of the cleft. The NAM protocol improved facial symmetry, mainly through nasal effects, whereas the absence of orthopedic therapy yielded a commitment to the face and maxillary arch symmetry.

Skeletal effects following developmental flame-retardant exposure are specific to sex and chemical class in the adult Wistar rat

Introduction: Accumulating evidence reveals that endocrine disrupting chemicals (EDCs) can disrupt aspects of metabolic programming, suggesting that skeletal development may be at risk, a possibility that is rarely examined. The commercial flame retardant (FR) mixture, Firemaster 550 (FM 550), has repeatedly been shown to negatively influence metabolic programming, raising concerns that skeletal integrity may consequently be impaired. We have previously shown that gestational and lactational exposure to 1,000 µg FM 550 negatively affected sex-specific skeletal traits in male, but not female, rats assessed at 6 months of age. Whether this outcome is primarily driven by the brominated (BFR) or organophosphate ester (OPFR) portions of the mixture or the effects persist to older ages is unknown. Materials and methods: To address this, in the present study, dams were orally exposed throughout gestation and lactation to either 1,000 μg BFR, 1,000 µg OPFR, or 2,000 µg FM 550. Offspring (n = 8/sex/exposure) were weaned at PND 21 and assessed for femoral cortical and trabecular bone parameters at 8 months of age by high-resolution X-ray micro-computed tomography (micro-CT). Serum levels of serotonin, osteocalcin, alkaline phosphatase, and calcium were quantified. Results: FM 550 affected both sexes, but the females were more appreciably impacted by the OPFRs, while the males were more vulnerable to the BFRs. Conclusion: Although sex specificity was expected due to the sexual dimorphic nature of skeletal physiology, the mechanisms accounting for the male- and female-specific phenotypes remain to be determined. Future work aims to clarify these unresolved issues.

The participation of tumor residing pericytes in oral squamous cell carcinoma

Pericytes are perivascular cells related to vessel structure and angiogenesis that can interact with neoplastic cells, interfering with cancer progression and outcomes. This study focused on the characterization of pericytes in oral squamous cell carcinoma (OSCC) using clinical samples and a transgenic mouse model of oral carcinogenesis. Nestin^-/NG2⁺ (type-1) and nestin⁺/NG2⁺ (type-2) pericytes were analyzed by direct fluorescence after induction of oral carcinogenesis (4-nitroquinoline-1-oxide). Gene expression of neuron glial antigen-2 (NG2), platelet-derived growth factor receptor beta (PDGFR-β), and cluster of differentiation 31 (CD31) was examined in human OSCC tissues. The protein expression of von Willebrand factor and NG2 was assessed in oral leukoplakia (i.e., oral potentially malignant disorders) and OSCC samples. Additionally, clinicopathological aspects and survival data were correlated and validated by bioinformatics using The Cancer Genome Atlas (TCGA). Induction of carcinogenesis in mice produced an increase in both NG2⁺ pericyte subsets. In human OSCC, advanced-stage tumors showed a significant reduction in CD31 mRNA and von Willebrand factor-positive vessels. Low PDGFR-β expression was related to a shorter disease-free survival time, while NG2 mRNA overexpression was associated with a reduction in overall survival, consistent with the TCGA data. Herein, oral carcinogenesis resulted in an increase in NG2⁺ pericytes, which negatively affected survival outcomes.

Extracellular Vesicles in Bone Remodeling and Osteoporosis

Osteoporosis is a systemic disorder characterized by bone mass loss, leading to fractures due to weak and brittle bones. The bone tissue deterioration process is related to an impairment of bone remodeling orchestrated mainly by resident bone cells, including osteoblasts, osteoclasts, osteocytes, and their progenitors. Extracellular vesicles (EVs) are nanoparticles emerging as regulatory molecules and potential biomarkers for bone loss. Although the progress in studies relating to EVs and bone loss has increased in the last years, research on bone cells, animal models, and mainly patients is still limited. Here, we aim to review the recent advances in this field, summarizing the effect of EV components such as proteins and miRNAs in regulating bone remodeling and, consequently, osteoporosis progress and treatment. Also, we discuss the potential application of EVs in clinical practice as a biomarker and bone loss therapy, demonstrating that this rising field still needs to be further explored.

Indices in dental image exams for bone mineral density evaluation of aromatase inhibitor users

We evaluated the accuracy of radiomorphometric indices (RI) and fractal dimension (FD) for screening bone mineral density (BMD) in postmenopausal patients who had breast cancer and were using aromatase inhibitors (AI). The sample consisted of 40 participants. Digital panoramic radiography (DPR) and cone beam computed tomography (CBCT) were evaluated along with dual-energy X-ray absorptiometry (DXA), which is the gold standard for detecting low BMD. According to the T-scores of DXA, the subjects were assigned into two groups: with normal BMD and with low BMD (osteopenia and osteoporosis). The area under the curve (AUC), sensitivity, and specificity with their respective confidence intervals were determined for DPR and CBCT. For DPR indices, AUC ranged from 52.6 to 75.8%. The mandibular cortical width (MCW) had the highest AUC. For FD, the total trabecular index had the highest sensitivity, while the index anterior to the mental foramen (MF) had the highest specificity. In CBCT, the AUC ranged from 51.8 to 62.0%. The indices with the highest AUC were the molar (M) and anterior (A). The symphysis (S) index had the highest sensitivity and the posterior (P) index had the highest specificity. Sensitivity and specificity were adequate for the computed tomography index (Inferior; CTI [I]). Therefore, MCW, FD of the mandible angle, and total trabecular ROI in DPR and the CTI (I), M, P, and A indices in CBCT proved to be promising tools in distinguishing individuals with low BMD. Cutoff point for these indices could be a useful tool to investigate low BMD in postmenopausal women taking AI.

Methotrexate promotes recovery of arthritis-induced alveolar bone loss and modifies the composition of the oral-gut microbiota

OBJECTIVES

The impact of rheumatoid arthritis (RA) on the shaping of the oral and gut microbiome raises the question of whether and how RA treatment modifies microbial communities. We examined changes in the oral and gut microbiota in a mouse model of antigen-induced arthritis (AIA) treated or not with methotrexate (MTX).

METHODS

Maxillae and stools were evaluated by the MiSeq platform of the V4 region of the 16S rRNA gene. Alveolar bone parameters were analysed by micro-computed tomography. Moreover, arthritis-induced changes in hyperalgesia and oedema were assessed, along with the impact on periodontal bone health.

RESULTS

Microbial communities in MTX-treated AIA mice revealed distinct clusters compared to the control and AIA groups. Overall, MTX impacted the richness and variability of microorganisms in the oral-gut axis microbiome at the phylum level. Regarding the oral microbiome, while in the control group the most dominant phylum was Firmicutes, in the AIA group there was a shift towards the predominance of Campilobacteriota and Bacteroidetes associated with the disease. MTX treatment led to greater dominance of the health-associated phylum Proteobacteria. In the gut microbiome, AIA induction resulted in increased abundance of the Verrucomicrobiota phylum, and MTX treatment restored its levels compared to control. Importantly, the MTX-treated AIA animals had significantly less periodontal bone loss, as well as decreased hyperalgesia and joint oedema compared to the AIA animals.

CONCLUSION

Data suggest the benefit of MTX treatment in protecting alveolar bone, in addition to providing new insights on the drug-microbiome interaction in the course of RA.

Evaluation of periodontal parameters and gingival crevicular fluid cytokines in children with anterior open bite receiving passive orthodontic treatment with a spur

Objective

To evaluate clinical parameters and gingival crevicular fluid (GCF) cytokines in children with anterior open bite receiving passive orthodontic treatment with spurs.

Methods

Twenty children with indications for interceptive orthodontic treatment, an anterior open bite, and good oral hygiene and periodontal health were included in this study. GCF samples were collected from the mandibular and maxillary central incisors before (baseline) and 24 hours and 7 days after spur bonding. Clinical and periodontal examinations and cytokine analyses were performed.

Results

At 7 days after spur attachment, gingival bleeding in the mandibular group was increased relative to that in the maxillary group. Visible plaque was correlated with gingival bleeding at 7 days and the GCF volume at 24 hours after spur attachment. Compared with those at baseline, interleukin (IL)-8 levels in the maxillary group and IL-1β levels in both tooth groups increased at both 24 hours and 7 days and at 7 days, respectively. At 24 hours, IL-8, IL-1β, and IL-6 levels were higher in the maxillary group than in the mandibular group. Cytokine production was positively correlated with increased GCF volume, but not with gingival bleeding, visible plaque, or probing depth.

Conclusions

Although orthodontic treatment with spurs in children resulted in increased gingival bleeding around the mandibular incisors, IL levels were higher around the maxillary incisors and not correlated with periodontal parameters. Increased cytokine levels in GCF may be associated with the initial tooth movement during open bite correction with a passive orthodontic appliance in children.

Open bite

The Panorama of Cleft Lip and Palate Live Birth in Brazil: Follow-up of a 10-Year Period and Inequalities in the Health System

OBJECTIVE

To provide the prevalence and an overview of cleft lip and palate (CL/P) in the period of 2008 to 2017, as well as the profile of care provided for this condition in Brazil.

DESIGN

Cross-sectional study of epidemiological character.

SETTING

Brazilian government website.

PARTICIPANTS

National Live Birth and Hospital Information System.

INTERVENTION

Organization of the end databases and performance-based statistical analysis.

MAIN OUTCOME MEASURE(S)

Analysis of the prevalence of CL/P in newborns, sociodemographic condition of the mothers, surgical procedures and hospitalizations, and specialized hospitals in Brazil within a 10-year period.

RESULTS

The average prevalence of CL/P in Brazil was ∼52 children per 100 000 live births in the covered period, corresponding to 1 per 1924 newborns. The presence of cleft was associated with preterm birth, being underweight, and the male gender. The highest prevalence was found in the South region, while the lowest was found in the Northeast region, with increasing rates in the North region of Brazil. The states with the highest prevalence were not those with a great number of hospitalizations and surgical procedures for live births with CL/P.

CONCLUSION

In the 10-year study period, the prevalence of CL/P was 0.52 newborns per 1000 live births, a result which differs among the states of Brazil. The need to reinforce the national monitoring of the prevalence and surgical procedures of cleft patients have also emphasized the need to improve public medical care for CL/P subjects.

Friction evaluation of an elastic chain positioned under or over the wire in self-ligating brackets

Objectives:

This study aimed to evaluate the frictional resistance produced by active and passive self-ligating brackets on stainless steel archwires in the absence or presence of elastomeric chains under or over the wire.

Materials and Methods:

Four types of self-ligating brackets were used: Two active and two passive. For each commercial brand, five brackets were bonded to an acrylic plate and the frictional resistance was evaluated with 0.018” and 0.019” × 0.025” stainless steel wires in three situations: Without elastomeric chain, with elastomeric chain placed under and over the wire.

Results:

The bracket type, cross-section of the wire, and type of ligation had significant interactions with each other; the frictional resistance was significantly lower with the use of passive self-ligated brackets, while no difference was found when a 0.018” wire was tested. Moreover, the frictional resistance in the absence of an elastomeric chain, or when the chain was under the wire, was significantly lower in comparison with the values obtained when the chain was placed on the wire.

Conclusion:

Frictional resistance of passive and active self-ligated brackets is influenced by the ligation methods and the cross-sectioning of archwires.

Effects of high-dose bisphenol A on the mouse oral mucosa: A possible link with oral cancers

Bisphenol A (BPA) is an endocrine disrupting chemical able to promote hormone-responsive tumors. The major route of BPA contamination being oral, the aim of the present study was to investigate BPA effects on oral cells. Here, we evaluated the impact of sub-chronic in vivo exposure to BPA and its in vitro effects on neoplastic and non-neoplastic oral cells. We evaluated the oral mucosa of mice chronically exposed to BPA (200 mg/L). The response of keratinocytes (NOK-SI) and Head and Neck (HN) Squamous Cell Carcinoma (SCC), HN12 and HN13 cell lines to BPA was examined. In vivo, BPA accumulated in oral tissues and caused an increase in epithelial proliferative activity. BPA disrupted the function of keratinocytes by altering pro-survival and proliferative pathways and the secretion of cytokines and growth factors. In tumor cells, BPA induced proliferative, invasive, pro-angiogenic, and epigenetic paths. Our data highlight the harmful effects of BPA on oral mucosa and, tumorigenic and non-tumorigenic cells. Additionally, BPA may be a modifier of oral cancer cell behavior by prompting a functional shift to a more aggressive phenotype.

Abnormalities in Microarchitecture and Reduced Mechanical Bone Strength in a Rat Model of Polycystic Ovary Syndrome

Evidence from the literature is contentious about the impact of polycystic ovary syndrome (PCOS) on the skeleton, suggesting a possible negative role of this condition on non-obese women. We investigated this hypothesis employing a well-characterized testosterone propionate (TP) rodent model of PCOS to address the consequences of androgenization on bone microarchitecture, histology, and mechanical strength. For this study, Wistar rats (n= 38) were divided in 4 groups: 1) “Control OVX” (single dose of corn oil s.c. at day 5 of life and ovariectomy at day 100, n=9); 2) “Control SHAM” (n=9); 3) “Androgenized OVX”(single dose of TP 1.25 mg s.c. at day 5 of life and ovariectomy at day 100, n=10); and 4) “Androgenized SHAM” (n=10). Full characterization of estrous cycles and weight was performed during growth, and all animals were euthanized at day 180. Successful ovariectomy was confirmed by neglected levels of serum estradiol. Endpoints evaluated include bone micro CT (femur and spinal column), bone histology (number of osteoclasts and osteoblasts in the femur), and mechanical tests. The study was approved by the local Ethics Committee. At the end of the study (day 180), Androgenized OVX rats were heavier than the other three groups. MicroCT Analysis: Androgenized SHAM rats exhibited a significantly higher trabecular mass in the spine (BV/BT) (mean + SEM) 49.21 + 2.42 % versus Control SHAM 36.42 + 1.39 % (Student T-test p=0.001). Following ovariectomy, BV/BT in Androgenized OVX was 40.4 + 2.83 % against 20.34 + 1.85 % in Control OVX (Student T-test p=0.0003). Lumbar trabecular thickness(μm) was also higher in Androgenized OVX (p=0.0065) as well the Trabecular number (n/mm)(p=0.0003). A similar increase in trabecular mass was observed in the femur. Androgenized SHAM rats had a significant higher BV/BT (%), trabecular thickness(μm), and decreased trabecular separation (p < 0.001). However, a significant reduction in cortical bone (thickness) was noted (Student T-test p=0.001). A histological study of the distal femur of Androgenized SHAM rats also show a significantly increased number of osteoclasts and decreased number of osteoblasts than Control SHAM (0< 001). When submitted to the mechanical test, Androgenized Sham rats presented a decreased strength (p<0.01) in relation to its controls. After ovariectomy, there was a reduction in bone in all oophorectomized groups. However, differently than the vertebral bones, no differences regarding bone mechanical strength or stiffness as well microCT values, or bone histology parameters were noted in the femur of Control OVX or Androgenized OVX. Our results suggest that androgenization in a rodent model of PCOS leads, at the same time, to a generalized increase in trabecular (cancellous) bone mass (especially in the spine), associated with a reduced cortical bone mass and decreased strength of the femur.

Metabolic profile of female lambs on annual ryegrass pasture managed under different grazing intensities and methods

ABSTRACT The aim of this study was to evaluate the effect of grazing methods and intensities on the metabolic profile of lambs grazing ryegrass. This study was performed in Eldorado do Sul (RS). The treatments consisted of two grazing intensities with rotational and continuous stocking methods: moderate and low. The experimental design was a randomized block arranged in a factorial scheme with four replicates. To evaluate the metabolic and nutritional conditions of the lambs, blood samples were collected to evaluate phosphorus, albumin, glucose, magnesium, globulin, cortisol, urea and total proteins. The highest blood urea value was observed in the month of September in lambs kept in continuous method grazing. There was no statistical difference between the grazing intensities and grazing methods for albumin, glucose, magnesium, globulin, cortisol and total protein levels in profile lambs. The cortisol values suggested that the animals were not subjected to high stress levels. In conclusion, rearing female lambs on ryegrass, irrespective of grazing methods or intensities, allowed the maintenance of body homeostasis and did not cause any metabolic unbalances, nutritional unbalances or stress.

Photobiomodulation drives pericyte mobilization towards skin regeneration

Photobiomodulation is being widely applied for improving dermal or mucosal wound healing. However, the underlying cellular and molecular processes that directly contribute to its effects remain poorly understood. Pericytes are relevant cells involved in the wound microenvironment and could be one of the main targets of photobiomodulation due to their plasticity and perivascular localization. Herein, we investigate tissue repair under the photobiomodulation stimulus using a pericyte labeled (or reporter) transgenic mice. Using a model of two contralateral back wounds, one the control and the other photoactivated daily (660 nm, 20 mW, 0.71 W/cm2, 5 J/cm2, 7 s, 0.14 J), we showed an overall influx of immune and undifferentiated cells and higher mobilization of a potent pericyte subpopulation (Type-2 pericytes) in the photoactivated wounds in comparison to the controls. Doppler analysis showed a significant increase in the blood flow in the photoactivated wounds, while marked vascular supply was observed histologically. Histochemical analysis has indicated more advanced stages of tissue repair after photoactivation. These data suggest that photobiomodulation significantly accelerates tissue repair through its vascular effects with direct recruitment of pericytes to the injury site.

Aerobic and resistance training improve alveolar bone quality and interferes with bone-remodeling during orthodontic tooth movement in mice

The direct effects of physical activity on long bones are already recognized. However, little information is available regarding distant osseous sites, such as maxillary bone. We evaluated the influence of physical training on alveolar bone quality, with and without mechanically-induced load during orthodontic tooth movement in mice. Forty-two C57BL/6 mice were divided into sedentary, resistance and aerobic training groups. Training period lasted for eight weeks and mechanical loads (orthodontic tooth movement - OTM) were applied during the last 14 days of training. Both types of training enhanced the quality of maxillary bone, increasing bone mineral density (BMD), trabecular bone volume (BV) and bone volume/total volume ratio (BV/TV). OTM significantly reduced in trained groups. Consistently, the number of osteoblasts increased whereas the number of osteoclasts decreased on the OTM side in trained groups in comparison to the sedentary group. IGF-1, RUNX2 and OPG genes expression were also increased. The RANKL/OPG ratio and IL-6 expression were reduced in the maxillary bone. Similar results were verified in the femoral bone. In line with these findings, physical training resulted in a decrease of osteoclast differentiation from femoral bone marrow; as well as the force required to fracture the tibia of trained animals increased. Physical training also caused EDL muscle hypertrophy and increased expression of IGF-1 and IGF-1/Myostatin ratio in the gastrocnemius muscle, whereas FNDC5 gene expression was similar among groups in femur, but decreased in alveolar bone submitted to OTM. In conclusion, physical training increased bone quality, not only on long bones, but also in a distant site such as the maxilla. Differences were more evident in the course of maxillary mechanical loading. Mechanisms involve systemic and local effects on bone cells and target molecules as RANKL, OPG, IL-6 and IGF-1.

Bovine Milk Extracellular Vesicles Are Osteoprotective by Increasing Osteocyte Numbers and Targeting RANKL/OPG System in Experimental Models of Bone Loss

Studying effects of milk components on bone may have a clinical impact as milk is highly associated with bone maintenance, and clinical studies provided controversial associations with dairy consumption. We aimed to evaluate the impact of milk extracellular vesicles (mEVs) on the dynamics of bone loss in mice. MEVs are nanoparticles containing proteins, mRNA and microRNA, and were supplemented into the drinking water of mice, either receiving diet-induced obesity or ovariectomy (OVX). Mice receiving mEVs were protected from the bone loss caused by diet-induced obesity. In a more severe model of bone loss, OVX, higher osteoclast numbers in the femur were found, which were lowered by mEV treatment. Additionally, the osteoclastogenic potential of bone marrow-derived precursor cells was lowered in mEV-treated mice. The reduced stiffness in the femur of OVX mice was consequently reversed by mEV treatment, accompanied by improvement in the bone microarchitecture. In general, the RANKL/OPG ratio increased systemically and locally in both models and was rescued by mEV treatment. The number of osteocytes, as primary regulators of the RANKL/OPG system, raised in the femur of the OVX mEVs-treated group compared to OVX non-treated mice. Also, the osteocyte cell line treated with mEVs demonstrated a lowered RANKL/OPG ratio. Thus, mEVs showed systemic and local osteoprotective properties in two mouse models of bone loss reflected in reduced osteoclast presence. Data reveal mEV potential in bone modulation, acting via osteocyte enhancement and RANKL/OPG regulation. We suggest that mEVs could be a therapeutic candidate for the treatment of bone loss.

The First-Year Follow-Up of a Cleft Lip and Palate Patient Treated With Nasoalveolar Molding (NAM)

The objectives of pre-surgical orthopedics are to allow surgical repair with minimal tension of the involved tissues and less restriction to the craniofacial growth. The aim of this study was to evaluate the benefits of nasoalveolar model (NAM) as a pre-operative therapy in a patient with bilateral cleft lip and palate followed by labioplasty and palatoplasty. A 15-day-old patient underwent orthopedic treatment with NAM. After pre-operative treatment, retraction of the pre-maxilla was observed with reduction of the fissure. Due to the successful effects of NAM treatment the patient had a one-step surgery for lip correction. Six months later, due to lip pressure the fissure was further decreased. After six months, the patient underwent palatoplasty. Both surgeries contributed to the remaining closure of the fissure, which were reduced by half compared to the end of pre-operative treatment. The uses of NAM as a pre-operative treatment approached the alveolar segments, centralized the pre-maxilla, decreased the cleft palate resulting in a marked improvement of the arch and provide superior surgical results. In addition, it allows the primary repair of the patient's lip with asymmetric bilateral fissure in only one-step surgery; in consequence, it will reduce treatment morbidity and decrease cost of treatment.

Estrogen protects dental roots from orthodontic-induced inflammatory resorption

OBJECTIVE

Root resorption is a side effect of orthodontic tooth movement (OTM). Despite the recognized role of estrogen on bone, there is little information about their effects on orthodontic-induced inflammatory root resorption (OIIRR). We aimed to investigate if estrogen deficiency affects OIIRR in two mice strains.

METHODS

Female Balb/C (Balb) and C57BL6/J (C57) mice were ovariectomized (OVX) and replaced with estradiol (E2). Tooth samples subjected or not to OTM were collected and analyzed by microCT, histomorphometry and qPCR.

RESULTS

OVX resulted in decreased root volume (RV/TV) and root mineral density (RMD) in Balb mice without OTM. In contrast, OVX did not modify physiological root structure of C57 mice. OTM and OIIRR were increased after OVX in both mice strains after 30 days. E2 replacement reversed this phenotype in Balb, but not in C57 mice. Due to the significant increase of OIIRR in OVX Balb mice, the expression of key molecules was investigated in periodontium. Accordingly, these mice showed increased expression of receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor alpha, matrix metalloproteinases-2 and -13 and decreased osteoprotegerin (OPG) and interleukin-10 expression after OTM. E2 replacement reversed the changes of these markers.

CONCLUSION

The lack of estrogen in Balb mice without OTM triggered loss of root structure which was positively correlated to RANKL/OPG ratio. Regardless of mouse strain, the absence of estrogen following OTM induced OIIRR. Mechanisms involve the imbalance of RANKL/OPG system, inflammatory and osteoclastic makers.

Maxillary suture expansion: A mouse model to explore the molecular effects of mechanically-induced bone remodeling

The aim of this study was to analyze the effect of rapid maxillary expansion (RME) on hard tissues. Opening loops bonded to the first and second maxillary molars on both sides were used to apply distracting forces of 0.28 N, 0.42 N and 0.56 N at the midpalatal suture for 7 and 14 days. Microcomputed tomography (MicroCT), histomorphometry and quantitative polymerase chain reaction (qPCR) analysis were performed to evaluate RME effectiveness, midpalatal suture remodeling, cell counting of osteoblasts, osteoclasts and chondrocytes and the expression of bone remodeling markers, respectively. All forces at the two different time points resulted in similar RME and enhanced of bone remodeling. Accordingly, increased number of osteoblasts and reduced chondrocytes counting and no difference in osteoclasts were seen after all RME protocols. RME yielded increased expression of bone remodeling markers as osteocalcin (Ocn), dentin matrix acidic phosphoprotein-1 (Dmp1), runt-related transcription factor 2 (Runx2), collagen type I Alpha 1 (Col1a1), alkaline phosphatase (ALP), receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (Rankl), osteoprotegerin (Opg), cathepsin K (Ctsk), matrix metalloproteinases 9 and 13 (Mmp9 and 13), transforming growth fator beta 1, 2 and 3 (Tgfb 1, Tgfb 2 and Tgfb3), bone morphogenetic protein 2 (Bmp-2), sclerostin (Sost), beta-catenin-like protein 1 (Ctnnbl) and Wnt signaling pathways 3, 3a and 5a (Wnt 3, Wnt 3a and Wnt 5a). These findings characterize the cellular changes and potential molecular pathways involved in RME, proving the reliability of this protocol as a model for mechanical-induced bone remodeling.

SUN-023 Changes in Microct Bone Density and Reduced Bone Formation in a “Postmenopausal” PCOS Rat Model

Polycystic ovary syndrome (PCOS) affects women during their entire lifespan. Evidence from the literature suggests an association of PCOS with decreased bone formation markers (osteocalcin and P1NP), although no conclusive data about the incidence of fractures exist. In the present study, we investigated the consequences of androgenization in rats on bone markers and femur microCT and the changes in these parameters after ovariectomy. This study was approved by the local Animal Ethics Committee. Briefly, Wistar rats (n= 38) were divided in 4 groups: 1) “Control OVX” (single dose of corn oil s.c. at day 5 of life and ovariectomy at day 100, n=9); 2) “Control SHAM” (n=9); 3) “Androgenized OVX”(single dose of testosterone propionate 1.25 mg s.c. at day 5 of life and ovariectomy at day 100, n=10); and 4) “Androgenized SHAM” (n=10). Full characterization of estrous cycles and weight was performed during growth, and all animals were euthanized at day 180 during metestrus/diestrous. Evaluation of glucose levels, lipids, estradiol, P1NP levels (a marker of bone formation), and analysis of the femur micro CT Skyscan 1174 (Aartselaar, Belgium) was performed in at least eight animals of each group. Ovariectomy increased the weight of Androgenized OVX rats on day 180: these animals were heavier than Control OVX, Control SHAM, or Androgenized SHAM (ANOVA p<0.001). However, metabolic changes were observed in ovary-intact Androgenized SHAM rats who exhibited higher total cholesterol (ANOVA p<0.001), increased LDL (ANOVA p=0.03), and elevated TyG index, a marker of insulin resistance (ANOVA p<0.001) against all other three groups. This group (Androgenized SHAM rats)also exhibited an increase in MicroCt bone density (g/cm-3) (mean + SEM) of 1.117 + 0.06 against the other - Control SHAM 0.8433 + 0.03, Control OVX 0.5527 + 0.001, and Androgenized OVX 0.6284 + 0.02 (ANOVA p< 0.001). Although the values of bone density between Control OVX and Androgenized OVX groups were similar, gonadal removal produced a different pattern of bone density reduction between Control OVX and Androgenized OVX (Two-Way ANOVA p=0.001). Moreover, we found P1NP levels significantly decreased in the Androgenized OVX group (mean + SEM) of 58.57 + 4.41 ng/ml against 88.02 + 8.49 ng/ml in Control OVX versus (ANOVA p<0.0001) indicating lower bone formation. Our results suggest that bone and metabolic features of Androgenized rats are affected by ovariectomy with a negative impact on bone formation.

Inhibitory effects of dabigatran etexilate, a direct thrombin inhibitor, on osteoclasts and osteoblasts

INTRODUCTION

Anticoagulants are widely used in orthopedic surgery to decrease the risk of deep vein thrombosis. While significant bone impairment is induced by long-term heparin therapy, little is known about the effects of direct oral anticoagulants (DOACs). Herein, we investigated the effects of dabigatran etexilate (Pradaxa®), a DOAC inhibitor of thrombin, on bone cells using in vitro and ex vivo cell culture models.

MATERIALS AND METHODS

Osteoblasts and osteoclasts exposed to different concentrations of dabigatran etexilate and untreated cells were assayed for cell differentiation and activity. Favorable osteogenic conditions for osteoblasts were tested using titanium with nanotopography (Ti-Nano). In addition, mice treated with a dabigatran etexilate solution had bone marrow cells analyzed for the ability to generate osteoclasts.

RESULTS

Dabigatran etexilate at concentrations of 1 μg/mL and 2 μg/mL did not impact osteoclast or osteoblast viability. The drug inhibited osteoclast differentiation and activity as observed by the reduction of TRAP+ cells, resorption pits and gene and protein expression of cathepsin K. Consistently, osteoclasts from mice treated with dabigatran showed decreased area, resorptive activity, as well as gene and protein expression of cathepsin K. In osteoblast cultures, grown both on polystyrene and Ti-Nano, dabigatran etexilate reduced alkaline phosphatase (ALP) activity, matrix mineralization, gene expression of ALP and osteocalcin.

CONCLUSIONS

Dabigatran etexilate inhibited osteoclast differentiation in ex vivo and in vitro models in a dose-dependent manner. Moreover, the drug reduced osteoblast activity even under optimal osteogenic conditions. This study provides new evidence regarding the negative overall impact of DOACs on bone cells.

Comparison of the accuracy of virtual and direct bonding of orthodontic accessories

Introduction:

Conventional direct and indirect bonding techniques fail to obtain the ideal bracket position.

Objective:

To compare the accuracy of virtual and conventional direct bonding of orthodontic accessories.

Methods:

A single virtual configuration (dental mannequin with Class I malocclusion) served as basis for generating the reference model (treated virtually) and the intervention models (10 digital models and 10 solid models, obtained by means of prototyping). A total of 560 teeth were then equally distributed between a group of orthodontists (Group I, direct bonding; and Group II, virtual bonding), working in two different time intervals. The individual positions of the accessories were measured after three-dimensional superimposition with customized software. The Student’s-t test for paired samples, and Chi-square tests were used for statistical analysis, both at the level of significance of 5%.

Results:

In comparison of the errors in raw values, there were significant differences only in the vertical (p< 0.001) and horizontal dimensions (p< 0.001). Considering the groups of ranges by clinical limits of the deviations, these differences were significant in the three dimensions, vertical (p< 0.001), horizontal (p= 0.044) and angular (p= 0.044).

Conclusion:

Virtual bonding made it possible to obtain more precise/accurate positioning of the orthodontic accessories. The potential accuracy of this method brings new perspectives to refining the indirect bonding protocols.

Short-chain fatty acids and FFAR2 as suppressors of bone resorption

Short-chain fatty acids (SCFAs) exert a variety of immune and metabolic functions by binding to G-protein-coupled receptors, mainly free fatty acid receptor 2 (FFAR2). However, the effects of SCFAs and FFARs on bone remodeling, especially in alveolar bone, have been less explored. In this study, we investigated the influence of the SCFA/FFAR2 axis on alveolar bone. Bone samples from wild-type (WT) and FFAR2-deficient mice (FFAR2-/-) were analyzed using micro-CT, histology and qPCR. WT and FFAR2-/- animals received a high-fiber diet (HFD) reported to increase circulating levels of SCFAs. Additionally, we analyzed the effects of SCFAs and a synthetic FFAR2 agonist, phenylacetamide-1 (CTMB), on bone cell differentiation. The participation of histone deacetylase inhibitors (iHDACs) in the effects of SCFAs was further assessed in vitro. CTMB treatment was also evaluated in vivo during orthodontic tooth movement (OTM). FFAR2-/- mice exhibited deterioration of maxillary bone parameters. Consistent with this, FFAR2-/- mice exhibited a significant increase of OTM and changes in bone cell numbers and in the expression of remodeling markers. The HFD partially reversed bone loss in the maxillae of FFAR2-/- mice. In WT mice, the HFD induced changes in the bone markers apparently favoring a bone formation scenario. In vitro, bone marrow cells from FFAR2-/- mice exhibited increased differentiation into osteoclasts, while no changes in osteoblasts were observed. In line with this, differentiation of osteoclasts was diminished by SCFAs and CTMB. Moreover, CTMB treatment significantly reduced OTM. Pretreatment of osteoclasts with iHDACs did not modify the effects of SCFAs on these cells. In conclusion, SCFAs function as regulators of bone resorption. The effects of SCFAs on osteoclasts are dependent on FFAR2 activation and are independent of the inhibition of HDACs. FFAR2 agonists may be useful to control bone osteolysis.

Influence of interdigitation and expander type in the mechanical response of the midpalatal suture during maxillary expansion

BACKGROUND AND OBJECTIVE

The orthopedic Maxillary Expansion (ME) procedure is used for treating the transverse maxillary deficiency. This pathology consists in a smaller transverse dimension in the maxilla and leads to malocclusion. The treatment takes advantage of the existence of the midpalatal suture (MPS), which corresponds to the junction at the palatine bones of its horizontal portions. The technique employs a device, conventionally a palatal expander attached to the posterior teeth, to separate the two maxillary bones in the MPS. The objective of this study was to analyze, using the Finite Element Method, the biomechanical behavior of the MPS when an expansion is applied.

METHODS

A Computer Tomography image of the maxilla was reconstructed, the suture geometry was modeled with different interdigitation levels and types of hyrax devices. A total of 12 geometric models (three levels for interdigitation and four types of hyrax devices) were prepared and analyzed taking into account the chewing forces and the expansion displacement. For each case, maximum principal stresses on the maxilla (bone), and equivalent stresses on the expander device (stainless steel) were observed. In the MPS, maximum principal stresses and directional displacement were evaluated.

RESULTS

The results showed that the interdigitation does not have an important influence on the deformation behavior of the maxilla but it affects the stress distribution. In addition, the type of expander device and anchorage have a direct relationship with the treatment effectiveness; larger deformation in the expansion direction was obtained with skeletal when compared to dental anchorage.

CONCLUSIONS

A study that allows a better understanding of the oral biomechanics during the application of ME was presented. To our knowledge, it is the first study based on computational simulations that takes into account bone structures, like maxilla and part of the skull, to analyze the interdigitation influence on the MPS behavior when exposed to a ME.

Grazing criteria for perennial peanut (Arachis pintoi cv. Amarillo) consumed by sheep in rotational stocking

ABSTRACT The objective of work was to study the productive profile of perennial peanut in a rotational stocking environment under different criteria. The treatments corresponded to pre-grazing height of 14 and 18cm or 95% of light interception (LI) distributed in a completely randomized design. The studied variables were forage mass, percentage of structural components, forage mass and the structural components in the lower and upper canopy strata. The entrance criterion of 18cm in height, despite having higher forage mass, presented lower percentage of leaves and higher percentage of stems and forage losses. The criteria of 14cm and 95% light interception presented similar production between them and the highest rate of forage accumulation. In all criteria, in the upper strata of pasture a higher percentage of leaves were found. The criteria of 95% LI and 14cm in height presented the best productive performances. The entry criterion of 18cm presented a higher mass of pre-grazing forage with lower percentage of dead material, but with higher forage losses, resulting from senescent leaves. Due to changes in the structural components, as grazing cycles increase, the interception of 95% of the incident light by the perennial peanut occurs at lower heights.

In-depth characterization of congenital Zika syndrome in immunocompetent mice: Antibody-dependent enhancement and an antiviral peptide therapy

BACKGROUND

Zika virus (ZIKV) infection during pregnancy may cause major congenital defects, including microcephaly, ocular, articular and muscle abnormalities, which are collectively defined as Congenital Zika Syndrome. Here, we performed an in-depth characterization of the effects of congenital ZIKV infection (CZI) in immunocompetent mice.

METHODS

Pregnant dams were inoculated with ZIKV on embryonic day 5.5 in the presence or absence of a sub-neutralizing dose of a pan-flavivirus monoclonal antibody (4G2) to evaluate the potential role of antibody-dependent enhancement phenomenon (ADE) during short and long outcomes of CZI.

FINDINGS

ZIKV infection induced maternal immune activation (MIA), which was associated with occurrence of foetal abnormalities and death. Therapeutic administration of AH-D antiviral peptide during the early stages of pregnancy prevented ZIKV replication and death of offspring. In the post-natal period, CZI was associated with a decrease in whole brain volume, ophthalmologic abnormalities, changes in testicular morphology, and disruption in bone microarchitecture. Some alterations were enhanced in the presence of 4G2 antibody.

INTERPRETATION

Our results reveal that early maternal ZIKV infection causes several birth defects in immunocompetent mice, which can be potentiated by ADE phenomenon and are associated with MIA. Additionally, antiviral treatment with AH-D peptide may be beneficial during early maternal ZIKV infection. FUND: This work was supported by the Brazilian National Science Council (CNPq, Brazil), Minas Gerais Foundation for Science (FAPEMIG), Funding Authority for Studies and Projects (FINEP), Coordination of Superior Level Staff Improvement (CAPES), National Research Foundation of Singapore and Centre for Precision Biology at Nanyang Technological University.

Influence of clinical experience on accuracy of virtual orthodontic attachment bonding in comparison with the direct procedure

OBJECTIVES

To compare the accuracy of bonding orthodontic attachments in a digital environment with the direct bonding procedure depending on the level of the orthodontist's clinical experience.

MATERIALS AND METHODS

A total of 1120 artificial teeth of 40 identical models (20 solid sets + 20 digital sets) were divided into four groups: (1) direct bonding (experienced clinicians). (2) direct bonding (postgraduate students), (3) virtual bonding (experienced clinicians), and (4) virtual bonding (postgraduate students). The differences in individual position of the placed attachments were measured after three-dimensional superimposition of the models using customized software.

RESULTS

In the interoperator comparison, experienced clinicians were more exact than postgraduate students in virtual bonding in the angular dimension. Between the bonding techniques, virtual bonding was more accurate than the direct technique. The prevalence of errors was higher in the direct procedure than virtual bonding, and the errors were more significant in the premolar and molar teeth.

CONCLUSIONS

Clinical experience had a positive influence in achieving a higher rate of correctness/accuracy in the angular dimension only during virtual bonding. Virtual bonding was more accurate than direct bonding in the vertical and horizontal dimensions. Early diagnosis of errors in the bonding positions of attachments could be of benefit to both clinicians and patients by predicting discrepancies that may lead to undesirable orthodontic movements.

ST2 regulates bone loss in a site-dependent and estrogen-dependent manner

Interleukin-33 (IL-33) and its receptor, ST2, are implicated in bone remodeling. The lack of estrogen after menopause results in an accelerated bone loss. Here we investigated the role of ST2 in the bone loss induced by estrogen deficiency. ST2-deficient mice (ST2^-/- ) and their littermates (wildtype [WT]) were ovariectomized (OVX), while ovary-intact mice were used as controls. Bone sites were analyzed by microcomputed tomography, histomorphometry, and quantitative real-time polymerase chain reaction (qPCR). Deletion of IL-33 or ST2 resulted in a similar bone loss in the femur and maxilla. Ovariectomy in WT mice caused bone loss in the same areas. The lack of ST2 in OVX mice did not alter bone remodeling in the femur but prevented bone loss in the maxilla. Consistently, ovariectomy increased the IL-33 messenger RNA (mRNA) levels in the maxilla but not in the femur. Under mechanical stimulation, ovariectomy and ST2 deletion independently increased bone remodeling induced by orthodontic tooth movement, which was also associated with a greater number of osteoclasts and a reduced number of osteoblasts in the maxillary bone. ST2^-/- OVX mice, however, displayed twice as many osteoblasts as that of WT OVX mice. Ovariectomy and ST2 deletion differently altered the cytokine mRNA levels in the maxilla. Remarkably, interleukin-10 expression was decreased in both WT OVX and ST2^-/- mice, and this reduction was completely restored in ST2^-/- OVX mice. The results demonstrate that estrogen and IL33/ST2 independently protect against bone loss. However, the ovariectomy-induced bone loss is IL-33/ST2-dependent in the maxilla but not in the femur, indicating a bimodal and site-specific role of ST2 in bone remodeling.

Lactation induces increases in the RANK/RANKL/OPG system in maxillary bone

The underlying causes of maxillary bone loss during lactation remain poorly understood. We evaluated the impact of lactation on physiological and mechanically-induced alveolar bone remodeling. Nulliparous non-lactating (N-LAC) and 21-day lactating (LAC) mice underwent mechanically-induced bone remodeling by orthodontic tooth movement (OTM). Micro-computed tomography (microCT) was performed in the maxilla, femur and vertebra. Tartrate-resistant-acid phosphatase (TRAP) and Masson's trichrome labelling was performed in the maxillary bone and gene expression was determined in the periodontal ligament. The effect of prolactin on osteoclast (OCL) and osteoblast (OBL) differentiation was also investigated in N-LAC and LAC mice. Lactation increased alveolar bone loss in the maxilla, femur and vertebra, while OTM was enhanced. The number of OCL and OBL was higher in the maxilla of LAC mice. OTM increased OCL in both groups; while OBL was increased only in N-LAC but not in LAC mice, in which cell numbers were already elevated. The alveolar bone loss during lactation was associated with increased expression of receptor activator of nuclear factor-KappaB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) in the maxilla. OTM induced the same responses in N-LAC mice, whereas it had no further effect in LAC mice. Lactation enhanced differentiation of OCL and OBL from bone marrow cells, and prolactin recapitulated OCL differentiation in N-LAC mice. Thus, lactation increases physiological maxillary bone remodeling and OTM, and both require activation of RANK/RANKL/OPG system. These findings expand our knowledge of lactation-induced osteopenia and have possible impact on clinical practice regarding orthodontic treatments and dental implants in lactating women.

Diet versus jaw bones: Lessons from experimental models and potential clinical implications

The consumption of different types of diets influences not only body health but the bone remodeling process as well. Nutritional components can directly affect maxillary and mandibular alveolar bone microarchitecture. In this review, we focus on the current knowledge regarding the influence of diets and dietary supplementation on alveolar bone. Accumulating evidence from experimental models suggests that carbohydrate- and fat-rich diets are detrimental for alveolar bone, whereas protective effects are associated with consumption of calcium, ω-3, and bioactive compounds. Little is known about the effects of protein-free and protein-rich diets, boron, vitamin C, vitamin E, zinc, and caffeine on alveolar bone remodeling. Adipokines and direct effects of nutritional components on bone cells are proposed mechanisms linking diet and bone. Results from animal models substantiate the role of nutritional components on alveolar bone. It is a well-built starting point for clinical studies on nutritional monitoring and intervention for patients with alveolar bone disorders, especially those who are treatment refractory.

Probiotic consumption decreases the number of osteoclasts during orthodontic movement in mice

AIMS

The aim of the present study was to investigate the effect of probiotic (Bacillus Subtilis) supplementation on bone remodelling induced by mechanical loading.

METHODS

C57BL/6 mice were divided in two groups: (1) Probiotic and (2) Vehicle (water). The probiotic (1.5×10⁸CFU/mL) was administered orally for 14 days, starting two days before the induction of orthodontic tooth movement (OTM). OTM was determined by histomorphometric analysis by comparing the right to the left side of the maxilla. The number of osteoclasts was determined by counting TRAP-positive cells. Osteoblasts were counted on Masson's trichrome-stained slides.

RESULTS

OTM was similar between groups (with and without probiotic supplementation) (p=0.46). The number of TRAP-positive cells increased (p<0.01) on the experimental side (where the spring coil was installed) in comparison to the control side in both groups. However, the number of osteoclasts decreased (p˂0.01) in the probiotic group, in comparison to the vehicle group. There was an increase in the number of osteoblasts (p˂0.05) in both the Vehicle and Probiotic groups on the side under OTM, independent of probiotic supplementation.

CONCLUSION

Oral Supplementation with a probiotic influenced the number of osteoclasts adjacent to the tooth root during orthodontic movement in mice.

Osteoprotective Effects of IL-33/ST2 Link to Osteoclast Apoptosis

The relevance of IL-33 and its receptor ST2 for bone remodeling is not well-defined. Our aim was to assess the role and underlying mechanisms of IL-33/ST2 in mechanically induced bone remodeling. BALB/c (wild type) and ST2 deficient (St2(-/-)) mice were subjected to mechanical loading in alveolar bone. Microtomography, histology, and real-time quantitative PCR were performed to analyze bone parameters, apoptosis and bone cell counts, and expression of bone remodeling markers, respectively. MC3T3-E1 osteoblastic cells and bone marrow cells were used to verify if mechanical force triggered IL-33 and ST2 expression as well as the effects of IL-33 on osteoclast differentiation and activity. Mechanical loading increased the expression of IL-33 and ST2 in alveolar bone in vivo and in osteoblastic cells in vitro. St2(-/-) mice had increased mechanical loading-induced bone resorption, number of osteoclasts, and expression of proresorptive markers. In contrast, St2(-/-) mice exhibited reduced numbers of osteoblasts and apoptotic cells in periodontium and diminished expression of osteoblast signaling molecules. In vitro, IL-33 treatment inhibited osteoclast differentiation and activity even in the presence of receptor activator of NF-κB ligand. IL-33 also increased the expression of pro-apoptotic molecules, including Bcl-2-associated X protein (BAX), cell-surface Fas receptor (FAS), FASL, FAS-associated death domain, tumor necrosis factor-related apoptosis-inducing ligand, and BH3 interacting-domain death (BID). Overall, these findings suggest that IL-33/ST2 have anti-osteoclastogenic effects and reduce osteoclast formation and activity by inducing their apoptosis.

Osteoprotective Effects of Estrogen in the Maxillary Bone Depend on ERα

Estrogen deficiency results in disruption of maxillary alveolar bone microarchitecture. Most of the actions of estrogen in long bones occur via estrogen receptor α (ERα). However, the function of ERα in the maxillary bone has not been defined. We aimed to investigate the role and underlying mechanisms of ERα in the physiological and mechanically induced alveolar bone remodeling in female and male mice. Wild-type (WT) and ERα−/− (ERKOα) mice were subjected to mechanically stimulated bone remodeling by inducing orthodontic tooth movement (OTM). The maxillary bone was analyzed using histomorphometric analysis, micro–computed tomography, quantitative polymerase chain reaction, and energy-dispersive spectroscopy. Bone marrow cells (BMCs) from WT and ERKOα mice were tested for their capacity to differentiate into osteoblasts and osteoclasts. Both male and female ERKOα mice exhibited marked reduction of alveolar bone mass and increased OTM. This response was associated with an increased number of osteoclasts and reduced number of apoptotic cells and osteoblasts in the periodontium and alveolar bone. Consistently, ERKOα mice exhibited lower levels of calcium in bone and increased expression of IL-33 (interleukin-33), TNF-α (tumor necrosis factor α), and IL-1β (interleukin-1β) and decreased expression of dentin matrix acidic phosphoprotein and alkaline phosphatase in periodontal tissues. Moreover, the differentiation of osteoclasts and osteoblasts in vitro was significantly higher in BMCs obtained from ERKOα. ERα is required to maintain the microarchitecture of maxillary alveolar bone. This process is linked to bone cell differentiation and apoptosis, as well as local production of inflammatory molecules such as IL-33, TNF-α, and IL-1β.

Microbial contamination and disinfection methods of pacifiers

OBJECTIVES

To evaluate the microbial contamination of pacifiers by Mutans Streptococci(MS) and the efficacy of different methods for their disinfection.

METHODS

Twenty-eight children were assigned to a 4-stage changeover system with a 1-week interval. In each stage, children received a new pacifier and the parents were instructed to maintain their normal habits for 1 week. After this time, the pacifiers were subjected to the following 4 disinfection methods: spraying with 0.12% chlorhexidine solution, Brushtox or sterile tap water, and immersion in boiling tap water for 15 minutes. Microbiological culture for MS and Scanning Electron Microscopy (SEM) were performed. The results were analyzed statistically by Friedman's non-parametric test (a=0.05).

RESULTS

The 0.12% chlorhexidine spray was statistically similar to the boiling water (p>0.05) and more effective than the Brushtox spray and control (p<0.05). The analysis of SEM showed the formation of a cariogenic biofilm in all groups with positive culture.

CONCLUSIONS

Pacifiers become contaminated by MS after their use by children and should be disinfected routinely. Spraying with a 0.12% chlorhexidine solution and immersion in boiling water promoted better disinfection of the pacifiers compared with a commercial antiseptic toothbrush cleanser (Brushtox).

Oestrogen regulates bone resorption and cytokine production in the maxillae of female mice

Oestrogen plays major role in bone metabolism/remodelling. Despite of well-established effect of oestrogen deficiency on long bones, it remains unclear whether alveolar bone is affected. We aimed to determine the effect of oestrogen-deficiency in the alveolar bone microarchitecture. C57BL6/J and Balb/c mice were ovariectomized and implanted with oil-(OVX) or 17β-estradiol (E2)-containing (OVX+E2) capsules. Ovary-intact mice were used as controls. The dose of E2 replacement was selected based on trophic effects on the uterus and femur bone loss. As determined by maxillary alveolar bone MicroCT analysis, both C57BL6/J and Balb/c OVX mice displayed decreased trabecular thickness, bone density and bone volume, and increased trabecular separation at 15 and 30 days after ovariectomy. These effects were associated with a reduction of trabecular bone percentage and cortical thickness in the femur. A significant loss of alveolar bone crest was also associated with ovariectomy in both mice strains. The E2 replacement fully prevented ovariectomy-induced alterations in the alveolar and femoral bones. Moreover, TNF-α (tumour necrosis factor-α) levels and RANKL/OPG (receptor activator of NF-κB ligand/osteoprotegerin) ratio were increased in the maxilla after OVX, and these responses were also reversed by E2. In conclusion, oestrogen deficiency causes maxillary alveolar bone loss, which is similar to the effects found in the femur. The release of inflammatory molecules like TNF-α, RANKL and OPG is the potential mechanism to the decrease of bone quality and alveolar bone crest.

Características produtivas de cordeiros terminados em confinamento com dietas contendo diferentes teores de borra de soja

Avaliou-se o efeito de dietas contendo diferentes teores de borra de soja sobre o consumo de nutrientes, o ganho de peso, as características de carcaça e os componentes do peso vivo de cordeiros terminados em confinamento. Foram utilizados 25 cordeiros, machos, castrados, da raça Texel, distribuídos aleatoriamente em cinco tratamentos compostos por proporções de 0%, 2,89%, 5,77%, 8,65% ou 11,55% de borra de soja na matéria seca das dietas. Houve redução linear do consumo de nutrientes, com exceção do consumo de extrato etéreo, que aumentou linearmente. O peso vivo ao abate, o ganho de peso diário, os pesos e rendimentos de carcaça quente e fria, e os pesos de perna e de costilhar diminuíram linearmente, ao passo que as proporções de rúmen e do trato gastrintestinal, com conteúdo, bem como o conteúdo gastrointestinal, aumentaram linearmente com o aumento dos níveis de borra de soja nas dietas. A proporção de perna foi influenciada de forma quadrática. O aumento da participação de borra de soja na dieta de cordeiros em sistema de confinamento leva à diminuição do desempenho produtivo dos animais. Contudo, o lucro diário obtido por animal não é influenciado, podendo-se inferir que a inclusão de borra de soja até o nível de 11,55% da matéria seca total da dieta é uma alternativa viável para a terminação de cordeiros em confinamento.

Comportamento ingestivo de cordeiros Texel e ideal alimentados com casca de soja

O presente experimento, conduzido no laboratório de ovinocultura da Universidade Federal de Santa Maria, teve como objetivo avaliar o comportamento ingestivo de cordeiros das raças Texel e Ideal, terminados em confinamento com dietas contendo diferentes teores de casca de soja em substituição da silagem de sorgo. Foram utilizados 40 cordeiros machos não castrados, sendo 20 provenientes da raça Texel e 20 da raça Ideal, desmamados aproximadamente aos 50 dias e confinados em baias individuais, distribuídos aleatoriamente em quatro grupos de acordo com o nível de inclusão de casca de soja na dieta: 0 %, 33,5 %, 66,5 % e 100 % de casca de soja em substituição a silagem de sorgo. O tempo despendido em atividades de alimentação, tempo de mastigação total e o tempo gasto por refeição diminuíram linearmente, enquanto que o período de ócio e a eficiência de alimentação e de ruminação aumentaram linearmente, com o aumento do nível de substituição de silagem de sorgo por casca de soja. Cordeiros da raça Texel permaneceram por mais tempo em atividades de ruminação e de mastigação total, gastaram mais tempo por refei-ção, permaneceram menos tempo em ócio e apresentaram menor eficiência de ruminação quando comparados com cordeiros da raça Ideal, quando confinados em fase de terminação.

Effect of 0.4% stannous fluoride gel on Streptococci mutans in relation to elastomeric rings and steel ligatures in orthodontic patients

BACKGROUND

Patients with fixed orthodontic appliances often experience an absolute increase in the number of Streptococci mutans colony-forming units (cfu). The aim of this investigation was to study the development of biofilm and S. mutans cfu in connection with stainless steel ligatures and elastomeric rings in orthodontic patients treated with and without 0.4% stannous fluoride gel (SFG).

MATERIAL

Forty-seven patients were divided into 2 groups: those treated with 0.4% SFG for 4 minutes (experimental) and those without 0.4% SFG (control). In each patient, elastomeric rings were used for ligation on 1 side of the dental arch midline, and stainless steel ligatures were used on the opposite side. Saliva samples were collected before and after appliance placement. At 15 and 30 days after appliance placement, biofilm samples from the stainless steel ligatures and the elastomeric rings were collected and subjected to microbiologic procedures and scanning electron microscopy (SEM) analysis.

RESULTS

The numbers of S. mutans cfu in the saliva and biofilm were not statistically different between the teeth fitted with elastomeric rings and stainless steel ligatures, or between the experimental and control groups. SEM analysis showed biofilm formation on both ligature ties.

CONCLUSIONS

Topical application of 0.4% SFG in orthodontic patients with elastomeric rings or stainless steel ligatures does not cause a significant decrease in S. mutans cfu in the saliva and biofilm.