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.

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.

SOCS2 regulates alveolar bone loss in Aggregatibacter actinomycetemcomitans-induced periodontal disease.

INTRODUCTION: The role of suppressor of cytokine signaling 2 (SOCS2) in Aggregatibacter actinomycetemcomitans (Aa)-induced alveolar bone loss is unknown; thus, it was investigated in this study. METHODS: Alveolar bone loss was induced by infecting C57BL/6 wild-type (WT) and Socs2-knockout (Socs2-/-) mice with Aa. Bone parameters, bone loss, bone cell counts, the expression of bone remodeling markers, and cytokine profile were evaluated by microtomography, histology, qPCR, and/or ELISA. Bone marrow cells (BMC) from WT and Socs2-/- mice were differentiated in osteoblasts or osteoclasts for analysis of the expression of specific markers. RESULTS: Socs2-/- mice intrinsically exhibited irregular phenotypes in the maxillary bone and an increased number of osteoclasts. Upon Aa infection, SOCS2 deficiency resulted in the increased alveolar bone loss, despite decreased proinflammatory cytokine production, in comparison to the WT mice. In vitro, SOCS2 deficiency resulted in the increased osteoclasts formation, decreased expression of bone remodeling markers, and proinflammatory cytokines after Aa-LPS stimulus. CONCLUSIONS: Collectively, data suggest that SOCS2 is a regulator of Aa-induced alveolar bone loss by controlling the differentiation and activity of bone cells, and proinflammatory cytokines availability in the periodontal microenvironment and an important target for new therapeutic strategies. Thus, it can be helpful in preventing alveolar bone loss in periodontal inflammatory conditions.

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.

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.

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.

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.

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.

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.

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.

Release of leachable products from resinous compounds in the saliva of children with anterior open bite treated with spur.

BACKGROUND: To evaluate the release of bisphenol-A glycidyl methacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), bisphenol A (BPA), and phthalates of the composite resin used in the bonding of spurs applied in the treatment of children with anterior open bite and its effects on human keratinocytes. METHODOLOGY: Saliva samples of 22 children were collected before spur attachment (baseline) and 30 minutes (min) and 24 hours (h) after spur bonding. Analysis was performed using high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (HPLC-MS/MS) and gas chromatography coupled to mass spectrometry (GC-MS). Standardized resin increments were added to three different dilutions of the cell culture medium. Keratinocytes (HaCaT) were cultivated in the conditioned media and evaluated for cell viability (MTT) and cell scratch assay. RESULTS: The levels of BisGMA (1.74±0.27 µg/mL), TEGDMA (2.29±0.36 µg/mL), and BPA (3.264±0.88 µg/L) in the saliva after 30 min, in comparison to baseline (0±0 µg/mL, 0±0 µg/mL, and 1.15±0.21 µg/L, respectively), presented higher numbers. After 24 h, the levels of the monomers were similar to the baseline. Phthalates showed no significant difference among groups. HaCat cells showed increased viability and reduced cell migration over time after exposure to methacrylate-based resin composites. CONCLUSION: Resin composites, used to attach spurs in children with anterior open bite during orthodontic treatment, release monomers after polymerization and can influence the behavior of human keratinocytes, even at very low concentrations. Orthodontists should be aware of the risks of the resinous compounds release and preventive procedures should be held to reduce patient exposure.

Irisin effects on bone: systematic review with meta-analysis of preclinical studies and prospects for oral health.

Bone quality is an important issue in dentistry. Low bone density may be associated with more severe periodontitis, and may influence implant therapy success. Recent evidence suggests that physical activity can improve alveolar bone quality. Irisin is an exercise-mediated peptide that might be involved in this process. We assessed the effect of exercise and that of intra-peritoneal irisin administration on bone quality in healthy and osteoporosis-induced rodents. This study was registered at PROSPERO (CRD42020184140), and followed PRISMA guidelines. A search by two independent examiners was conducted in five databases and gray literature up to July 2021, without restrictions regarding language or date of publication. Initially, they analyzed retrieved titles and abstracts (n=3,844) based on eligibility criteria. Of this total, 19 studies remained for full-text reading, and 16 proceeded to the data extraction and quality assessment phases. Meta-analyses were conducted (n= 6 studies) to establish the effects of irisin administration on cancellous bone mineral density (BMD). Exercise or irisin administration enhanced bone quality, but the meta-analysis showed that BMD increased only slightly in osteoporotic rodents (BMD: mean difference 0.03 mg/cm3 - 95% CI 0.01-0.05). This indicates that they had no significant benefits on the bones of healthy animals. Implications of key findings evidence the potential of irisin as an agent able to mitigate bone loss caused by osteoporosis, an outcome that could favor dental rehabilitation. More studies investigating the effect of irisin on alveolar bone are needed to elucidate its therapeutic viability and implications.

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-1ß levels in both tooth groups increased at both 24 hours and 7 days and at 7 days, respectively. At 24 hours, IL-8, IL-1ß, 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.

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.

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.

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.

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.

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.

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.

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

Abstract 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.