Occlusion development after premature loss of deciduous anterior teeth: preliminary results of a 24-month prospective cohort study.

OBJECTIVE: This study aimed to evaluate occlusion development after premature loss or extraction of deciduous anterior teeth, by means of a prospective cohort study. METHODS: Fifteen infants and children aged 1 to 5 years old were longitudinally assessed (with loss or extraction of deciduous anterior teeth [n = 9], and without tooth losses [n = 6]). Photographs and dental casts at the baseline and after 24 months of follow-up were performed. Dental casts were scanned, and linear measurements were made on the digitalized models (missing tooth space, arch perimeter, arch length, arch width, intercanine length and intercanine width). The t-test was used for groups comparisons (α = 0.05). RESULTS: Individuals' mean age at baseline was 2.93 (± 1.18) years. No statistically significant differences were observed in the missing tooth space in the group with tooth loss during the 24 months of follow-up (p > 0.05). Arch perimeter, arch length, arch width, intercanine length and intercanine width did not show differences between the groups (p > 0.05). Qualitative photographic evaluation revealed other changes in the dental arches and occlusion, such as exfoliation and eruption of deciduous teeth, eruption of permanent teeth, self-correction or establishment of malocclusion, among others. CONCLUSION: The results suggest that the premature loss of deciduous anterior teeth does not affect the perimeter, length and width of the dental arches; however, other alterations that lead to malocclusion could be established.

Occlusion development after premature loss of deciduous anterior teeth: preliminary results of a 24-month prospective cohort study

ABSTRACT Objective: This study aimed to evaluate occlusion development after premature loss or extraction of deciduous anterior teeth, by means of a prospective cohort study. Methods: Fifteen infants and children aged 1 to 5 years old were longitudinally assessed (with loss or extraction of deciduous anterior teeth [n = 9], and without tooth losses [n = 6]). Photographs and dental casts at the baseline and after 24 months of follow-up were performed. Dental casts were scanned, and linear measurements were made on the digitalized models (missing tooth space, arch perimeter, arch length, arch width, intercanine length and intercanine width). The t-test was used for groups comparisons (α = 0.05). Results: Individuals' mean age at baseline was 2.93 (± 1.18) years. No statistically significant differences were observed in the missing tooth space in the group with tooth loss during the 24 months of follow-up (p > 0.05). Arch perimeter, arch length, arch width, intercanine length and intercanine width did not show differences between the groups (p > 0.05). Qualitative photographic evaluation revealed other changes in the dental arches and occlusion, such as exfoliation and eruption of deciduous teeth, eruption of permanent teeth, self-correction or establishment of malocclusion, among others. Conclusion: The results suggest that the premature loss of deciduous anterior teeth does not affect the perimeter, length and width of the dental arches; however, other alterations that lead to malocclusion could be established.

RESUMO Objetivo: Este estudo teve como objetivo avaliar o desenvolvimento da oclusão após perda prematura ou extração de dentes decíduos anteriores, por meio de um estudo de coorte prospectivo. Métodos: Quinze bebês e crianças de 1 a 5 anos foram avaliados longitudinalmente (com perda ou extração de dentes anteriores decíduos [n = 9] e sem perdas dentárias [n = 6]). Foram realizadas fotografias e modelos dentais no início e após 24 meses de acompanhamento. Os modelos dentários foram escaneados e medidas lineares foram feitas nos modelos digitalizados (espaço dentário perdido, perímetro da arcada, comprimento da arcada, largura da arcada, comprimento intercaninos e largura intercaninos). O teste t foi utilizado para comparações entre grupos (α = 0,05). Resultados: A média de idade dos indivíduos no início do estudo foi de 2,93 (± 1,18) anos. Não foram observadas diferenças estatisticamente significativas no espaço dentário perdido no grupo com perda dentária durante os 24 meses de acompanhamento (p > 0,05). O perímetro da arcada, comprimento da arcada, largura da arcada, comprimento intercaninos e largura intercaninos não apresentaram diferenças entre os grupos (p> 0,05). A avaliação fotográfica qualitativa revelou alterações nas arcadas dentárias e na oclusão, como: esfoliação e erupção de dentes decíduos, erupção de dentes permanentes, autocorreção ou estabelecimento de má oclusão, entre outras. Conclusão: Os resultados sugerem que a perda prematura de dentes anteriores decíduos não afeta o perímetro, comprimento e largura das arcadas dentárias; entretanto, outras alterações que levam à má oclusão poderiam ser estabelecidas.

Influence of the maxillary dimensions and anterior teeth anatomy on the buccal impaction of upper permanent canines: A three-dimensional case-control study.

OBJECTIVE: The diagnosis of impacted upper permanent canines (IUPC) is a relatively common clinical finding. The aim of this study was to investigate the association of the buccal impaction of upper permanent canines with their dimensions and the maxilla bone base. MATERIAL AND METHODS: Cone beam computed tomography files of 66 patients were allocated into: impaction group (ICG/n=33/mean age 15.7±3.9 years), with 44 impacted canines by the buccal side; control group (CG/n=33/mean age 15.66±3.99 years), matched for age and sex, with 66 canines normally erupted. The following measurements were obtained from ICG and CG groups: linear and volumetric canine dimensions, linear measurements of upper permanent central and lateral incisors, measurements of the anterior perimeter and transverse segments of the maxilla. Independent Student's t-test was used for intergroup analysis with correction of Bonferroni (α=0,005). RESULTS: Higher values were found in the means of the variables regarding to the anterior teeth crowns in the ICG group, however, without a significant difference (P<0,005). The upper arch anterior perimeter of the individuals with canine impaction through buccal area was reduced compared to CG (P=0.001). CONCLUSIONS: It can be concluded that individuals with upper buccal impacted permanent canine showed a significantly smaller anterior perimeter of the maxillary arch when compared to the control group. Although greater canine mesiodistal diameter was found in this group, there is no statistical association with the occurrence of this condition.

Influence of the maxillary dimensions and lateral incisor anatomy on the palatal impaction of maxillary permanent canines: A three-dimensional case-control study.

OBJECTIVE: The diagnosis of impacted upper permanent canines (IUPC) is a relatively common clinical finding. The aim of this study was to investigate associations between the upper permanent canines palatal impaction, lateral incisors morphology and the maxilla bone base. MATERIAL AND METHODS: Cone-beam tomography files from 62 subjects were divided into 2 groups: impaction group (ICG/n=31; mean age 14.3±2.4) with 45 canines impacted on the palatal side and age- and sex-matched control group (CG/n=31; mean age 14.3±2.3), with 62 normally erupted canines. Linear and volumetric measurements of the lateral incisors, linear transversal measures and the maxillary anterior perimeter were taken. Independent Student's t-test was used for intergroup analysis with correction of Bonferroni. RESULTS: Significant differences were found for crown length and root diameter (buccal-palatal) (P<0.005). The maxillary anterior perimeter in the ICG was reduced in relation to the GC but not significantly (P=0.008). The transverse skeletal variables of the maxilla were equivalent in the intergroup comparison (P>0.005). CONCLUSION: Smaller dimensions in the crown length and in the upper permanent lateral incisors root buccal-palatal diameter were associated with the impaction of upper permanent canines on the palatal side. The maxillary transverse morphology did not show any association with the occurrence of this condition.

Three-dimensional micromorphology of human midpalatal suture and pterygomaxillary articular complex.

BACKGROUND: Sutures exist in the craniofacial area, and the pattern of maturation and synostosis of facial sutures is largely unknown. METHODS: For a comprehensive understanding of the three-dimensional circummaxillary suture micromorphology, human midpalatal suture (MPS) and pterygomaxillary articular complex from eight subjects' (five males, three females, 72-88 years old) autopsies were longitudinally scanned with microcomputed tomography. Additional histology was performed for hematoxylin and eosin staining. Sutural micromorphology was assessed by interdigitation index (II), obliteration index (OI) and obliteration number. Intergroup comparisons were performed with Kruskal-Wallis and Mann-Whitney U with Bonferroni correction (α = 0.005). Correlation with anteroposterior and craniocaudal gradients was assessed with Spearman's correlation test (α = 0.05). RESULTS: Maxillary region of MPS presented a higher II 1.50 (0.61) and obliteration number per slice 8 (9) (P < 0.005). OI was increased in palatomaxillary 35% (47%) followed by pterygopalatine suture 25% (49%) (P < 0.005). The II and OI of the MPS exhibited only a weak anteroposterior gradient, with relatively low correlations. Obliteration areas were found sporadically along the entire MPS. CONCLUSIONS: Based on these findings, it is conceivable that the success of nonsurgical maxillary expansion largely depends on individual variations in sutural morphology and maturation rather than appliance design.

3D analysis of maxillomandibular morphology in hyperdivergent and hypodivergent individuals: A cross-sectional study.

INTRODUCTION: The aim of this cross-sectional study was to investigate maxillomandibular morphology in hyperdivergent and hypodivergent individuals, using 3D surface models generated by cone-beam computed tomography (CBCT). METHODS: The sample consisted of 60 CBCTs (30 males, 30 females) patients aged 12-30 years, divided into two groups comprising hyperdivergent (≥35°) and hypodivergent (≤30°) individuals, according to the mandibular plane (MP) angle. Multiplanar reconstructions were used to mark the landmarks, and 3D surface models were created to evaluate structures of the maxillomandibular complex, including condyle, ramus, symphysis and palatal height. Intergroup comparisons were performed by independent t-test. Pearson's correlation test was used (P < .05) to evaluate the correlation of the MP angle with the angles and linear measurements of other structures. RESULTS: Significant differences were found between the groups regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. No differences (P > .05) were found for the condylar height, symphysis inclination angle or palatal height. Correlations (P < .05) were found between the MP angle and structures of the maxillomandibular complex. CONCLUSIONS: Hyperdivergent (MP ≥ 35°) and hypodivergent (MP ≤ 30°) individuals present different skeletal morphology regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. There is a significant correlation between MP angle and morphological structures such as condyle, ramus, symphysis, palatal plane angle and palatal-mandibular angle.

Effect of cigarette smoke on aesthetic brackets: an in vitro study.

OBJECTIVE: The objective of this study was to evaluate the effect of cigarette smoke (CS) on physical and mechanical properties of ceramic, polycarbonate and alumina ceramic brackets. The null hypothesis tested was that aesthetic brackets would not be influenced by CS. METHODS: Ninety aesthetic brackets were allocated to three groups (n = 30): ceramic (GCE), polycarbonate (GCO) and alumina ceramic (GPS). Ten samples of each group were assigned to color and surface roughness analysis, performed before (T0) and after (T1) exposure to CS; and twenty samples were allocated into control and experimental groups (n = 10) (not exposed and exposed to CS, respectively) for shear bond strength test (SBS). Exposure to CS followed an adaptation of the method described by Le Mesurier. Colorimetric reading, surface morphology and roughness, SBS and adhesive remnant index (ARI) were assessed. Statistical analysis comprised independent and paired t-tests, ANOVA/Tukey and Fisher's exact tests (α = 0.05). RESULTS: Changes were observed in brackets' color (NBS: GCE = 2.4; GCO = 1.9; GPS = 2.1), surface roughness (ΔRa: GCE = 1.1 ± 0.8 µm; GCO = 1.9 ± 1.5µm; GPS = -0.3 ± 0.1 µm / ΔRz: GCE = 1.4 ± 1.0 nm; GPS = -0.5 ± 0.1 nm); and SBS (GPS - experimental = 221.8 ± 48.6 N) after exposure to CS (p< 0.05). CONCLUSIONS: Exposure, in vitro, of aesthetic brackets to CS resulted in changes of color to darker and more opaque shades, surface roughness alterations, and higher SBS values. ARI scores were not associated with exposure to CS.

Influence of nasal septum deviation on fluctuating asymmetries of the nasomaxillary complex: A cross-sectional study.

An important parameter in diagnostic analysis and treatment planning of different biological areas is facial symmetry, and several etiological factors have been attributed to skeletal facial asymmetry. Although causality cannot be determined, previous studies have reported a relationship between the anatomical deviation of the nasal septum and facial development. Diagnosis is critical for patients in growth stages due to the association between nasal septum deviation (NSD) and abnormal growth of the nasomaxillary complex. To understand this relationship, this study aimed to investigate the influence of nasal septum deviation on fluctuating asymmetries (FA) of the nasomaxillary complex at different stages of skeletal maturation. Another goal was to determine whether an association exists between the degrees of septal deviation severity and asymmetry of the nasomaxillary complex. This was a retrospective, cross-sectional observational study comprising 60 selected cone-beam computed tomography (CBCT) scans that were divided into four groups (n = 15) according to the degree of septal deviation and skeletal maturation: mild deviation (MD; <10°), moderate to severe deviation (MSD; ≥10°), early group (EG), and late group (LG). The angle and area of deviation were measured for the greatest NSD, and a geometric morphometric approach was used to evaluate the nasal septum (NS) shape. The morphology of the nasomaxillary complex and the presence of fluctuating asymmetries were evaluated using 23 two-dimensional landmarks on the nasomaxillary complex (nasal, lateral, and palatal regions) with Procrustes ANOVA and Mann-Whitney test. Additionally, Spearman's correlation and multivariate regression were used to correlate the NSD with asymmetries in these regions. No significant differences were observed in the Procrustes FA scores of the nasomaxillary complex between the MD-EG × MSD-EG and MD-LG × MSD-LG (p > 0.05). However, the results of the multivariate regression revealed more specific aspects of asymmetry (asymmetry component), there was a positive correlation between the NSD angle and the palatal regions (p = 0.035 and p = 0.047, middle and posterior, respectively), and the nasal septum shape and anterior palatal regions (p = 0.039). The nasal and lateral regions did not correlate with the NSD angle in the multivariate regression analysis (p > 0.05). The results of this study indicate that there were no significant differences in the fluctuating asymmetry of the nasomaxillary complex between the mild and moderate to severe nasal septum deviation groups, in both early and late skeletal maturation stages. However, a positive correlation was observed in the degree of nasal septum deviation angle and asymmetry components of the middle and posterior palatal regions, likewise between the nasal septum shape and asymmetry components of the anterior palatal region. The diagnosis of nasal septum deviation by both physicians and dentists is important, as a relationship was observed with fluctuating asymmetry component of the palatal region. This information can guide the decision of the treatment planning for these individuals, and should be considered, especially in cases of severe septum deviation, due to the great anatomical proximity of these structures.

Dental staining after orthodontic debonding: effectiveness of two bleaching treatment protocols - in vitro study

Objective: The aim of this study was to compare the effectiveness of two bleaching treatment protocols to treat dental staining after orthodontic debonding. Materials and Methods: Twenty four bovine teeth were submitted to orthodontic bracket (Morelli, Edgewise Prescription, Slot 22) bonding (Transbond XT, 3M) and debonding, which were divided into three groups according to the bleaching protocol: hydrogen peroxide 10% (Whiteness, FGM) simulating home bleaching protocol (Home Bleaching Group), hydrogen peroxide 35% Whiteness, FGM) simulating dental office bleaching protocol (Office Bleaching Group) and Control Group, which was not exposed to any dental bleaching protocol, and stored in distilled water at 37°C. The specimens were submitted to the following processes: aging of resin remaining tegs by ultraviolet (UV), staining with coffee solution and tooth bleaching with 10% hydrogen peroxide (G1) and 35% hydrogen peroxide (G2). The color stability analysis (CIE color space L* a* b* was performed with Vita Easyshade Compact spectrophotometer before bonding (T0), after aging and staining processes (T1) and after bleaching treatment (T2). All teeth were stored in distilled water at 37°C between experimental times. The comparison between the groups and time effect evaluation were performed using ANOVA / Tukey ( =0.05) and ANOVA-MR with Bonferroni correction ( =0.016), respectively. Results: The color stability parameters L *, a * and b * indicated, with the exception of GC, a tendency of increase in T1 (G1 - L *: 76.72 ± 13.39; a *: 6.68 ± 3.71; b *: 43.14 ± 4.04 / G2: - L *: 75.78 ± 4.66; a *: 8.13 ± 2.75; b *: 43.42 ± 8.87), which reflected the tendency to decrease brightness in T1, followed by a tendency to return to T0 values (G1 - L *: 82.92 ± 12.16; a *: 4.25 ± 3.68; b *: 39.40 ± 9.49 / G2: - L *: 83.76 ± 8.02; a *: 8.76 ± 4.08; b *: 47.90 ± 5.88). Significant differences were observed in G2 in a * (T1: 8.13 ± 2.75, T2: 8.76 ± 4.08) and b * (T1: 43.42 ± 8.87; T2: 47.90 ± 5.88), indicating that this group did not return to the values presented in T0 (a *: 1.81 ± 1.70; b *: 35.40 ± 5.08) (p <0.05). Conclusion: Based on the results of this study, it can be concluded that home bleaching protocol presented better performance for dental surface whitening in an eventual staining after orthodontic debonding.

Objetivo: O objetivo deste estudo foi comparar a eficácia de dois protocolos de tratamento clareador para manchas dentárias causadas após a descolagem ortodôntica. Materiais e Métodos: Vinte e quatro dentes bovinos foram submetidos à colagem e descolagem de braquetes ortodônticos (Morelli, Prescrição Edgewise, Slot 22") (Transbond XT, 3M), que foram divididos em três grupos de acordo com o protocolo de clareamento: peróxido de hidrogênio 10% (Whiteness, FGM) simulando protocolo de clareamento caseiro (grupo clareamento caseiro), peróxido de hidrogênio 35% Whiteness, FGM) simulando protocolo de clareamento de consultório (grupo clareamento de consultório) e Grupo Controle, que não foi exposto a nenhum protocolo de clareamento dental, armazenado em água destilada a 37ºC. Os corpos de prova foram submetidos aos seguintes processos: envelhecimento das resinas remanescentes por ultravioleta (UV), manchamento em solução de café e clareamento dental com peróxido de hidrogênio 10% (G1) e peróxido de hidrogênio 35% (G2). A análise de estabilidade de cor (sistema CIE L* a* b*) foi realizada com espectrofotômetro Vita Easyshade Compact antes da colagem (T0), após os processos de envelhecimento e manchamento (T1) e após o tratamento clareador (T2). Todos os dentes foram armazenados em água destilada a 37 °C entre os tempos experimentais. A comparação entre os grupos e a avaliação do efeito do tempo foram realizadas utilizando ANOVA/Tukey ( =0,05) e ANOVA-MR com correção de Bonferroni ( =0,016), respectivamente. Resultados: Os parâmetros de estabilidade de cor L *, a* e b* indicaram, com exceção do GC, tendência de aumento em T1 (G1 - L*: 76,72 ± 13,39; a*: 6,68 ± 3,71; b*: 43,14 ± 4,04 / G2: - L* : 75,78 ± 4,66; a*: 8,13 ± 2,75; b*: 43,42 ± 8,87), o que refletiu a tendência de diminuição do brilho em T1, seguido de uma tendência de retorno aos valores de T0 (G1- L*: 82,92 ± 12,16 ; a*: 4,25 ± 3,68; b*: 39,40 ± 9,49 / G2: - L*: 83,76 ± 8,02; a*: 8,76 ± 4,08; b*: 47,90 ± 5,88). Foram observadas diferenças significativas no G2 em a* (T1: 8,13 ± 2,75, T2: 8,76 ± 4,08) e b* (T1: 43,42 ± 8,87; T2: 47,90 ± 5,88), indicando que esse grupo não retornou aos valores apresentados em T0 (a*: 1,81 ± 1,70; b*: 35,40 ± 5,08) (p<0,05). Conclusão: Com base nos resultados deste estudo, pode-se concluir que o protocolo de clareamento caseiro apresentou melhor desempenho para o clareamento da superfície dentária em um eventual manchamento após a descolagem ortodôntica.

Skeletal and alveolar changes in conventional rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE): a prospective randomized clinical trial using low-dose CBCT.

BACKGROUND: This prospective randomized clinical trial aimed to evaluate the immediate and short-term skeletal, dentoalveolar, and periodontal effects of rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE) in adolescent and young adult patients. METHODS: This study followed a two-arm, parallel, randomized clinical trial design that recruited patients with transverse maxillary deficiency in a 1:1 allocation ratio. Forty patients (14 men and 26 women) requiring maxillary expansion were randomly allocated to the RPE (n = 20, age = 14.0 ± 4.5) or MARPE (n = 20, age = 14.1 ± 4.2) groups. The assignment was performed via computer-generated block randomization, with a block size of four. Upon identical (35 turns) amount of expansion, low-dose cone-beam computed tomography images were taken before treatment (T0), immediately after expansion (T1), and after a 3-month consolidation period (T2). The primary outcome of this study comprised the assessment of midpalatal suture separation. Secondary outcomes included, skeletal, dentoalveolar, and periodontal measurements, which were performed at each time point. RESULTS: The frequency of midpalatal suture separation was 90% (18/20) and 95% (19/20) for the RPE and MARPE groups, respectively. A greater increase in nasal width in the molar region (M-NW) and greater palatine foramen (GPF) was observed immediately after the expansion (T1-T0) and consolidation periods (T2-T0) in the MARPE group compared to the RPE group (P < 0.05). The MARPE and RPE groups showed similar dentoalveolar changes except for the maxillary width (PM-MW, M-MW). The MARPE group presented greater bilateral first premolar (PM-MW) and molar (M-MW) maxillary width in relation to the RPE group (P < 0.05). Through the expansion and consolidation periods (T2-T0), lesser buccal displacement of the anchor teeth was observed in the MARPE group (PM-BBPT, PM-PBPT, M-BBPT [mesial and distal roots], and M-PBPT)( P < 0.05). CONCLUSIONS: Midpalatal suture separation was observed in 90% and 95% of patients in the RPE and MARPE groups, respectively. Both RPE and MARPE groups exhibited significant triangular basal bone expansion and skeletal relapse during consolidation. Under identical amounts of expansion, the MARPE group showed lower decrease in the skeletal, dentoalveolar and periodontal variables after consolidation. The reinforcement of RPE with miniscrews contributes to the maintenance of the basal bone during consolidation period. Trial registration WHO Institutional Clinical Trials Registry Platform (IRB No. KCT0006871 / Registration date 27/12/2021).

Surface Characteristics and Microbiological Analysis of a Vat-Photopolymerization Additive-Manufacturing Dental Resin.

The wide application of additive manufacturing in dentistry implies the further investigation into oral micro-organism adhesion and biofilm formation on vat-photopolymerization (VP) dental resins. The surface characteristics and microbiological analysis of a VP dental resin, printed at resolutions of 50 µm (EG-50) and 100 µm (EG-100), were evaluated against an auto-polymerizing acrylic resin (CG). Samples were evaluated using a scanning electron microscope, a scanning white-light interferometer, and analyzed for Candida albicans (CA) and Streptococcus mutans (SM) biofilm, as well as antifungal and antimicrobial activity. EG-50 and EG-100 exhibited more irregular surfaces and statistically higher mean (Ra) and root-mean-square (rms) roughness (EG-50-Ra: 2.96 ± 0.32 µm; rms: 4.05 ± 0.43 µm/EG-100-Ra: 3.76 ± 0.58 µm; rms: 4.79 ± 0.74 µm) compared to the CG (Ra: 0.52 ± 0.36 µm; rms: 0.84 ± 0.54 µm) (p < 0.05). The biomass and extracellular matrix production by CA and SM and the metabolic activity of SM were significantly decreased in EG-50 and EG-100 compared to CG (p < 0.05). CA and SM growth was inhibited by the pure unpolymerized VP resin (48 h). EG-50 and EG-100 recorded a greater irregularity, higher surface roughness, and decreased CA and SM biofilm formation over the CG.

Effect of cigarette smoke on aesthetic brackets: an in vitro study

ABSTRACT Objective: The objective of this study was to evaluate the effect of cigarette smoke (CS) on physical and mechanical properties of ceramic, polycarbonate and alumina ceramic brackets. The null hypothesis tested was that aesthetic brackets would not be influenced by CS. Methods: Ninety aesthetic brackets were allocated to three groups (n = 30): ceramic (GCE), polycarbonate (GCO) and alumina ceramic (GPS). Ten samples of each group were assigned to color and surface roughness analysis, performed before (T0) and after (T1) exposure to CS; and twenty samples were allocated into control and experimental groups (n = 10) (not exposed and exposed to CS, respectively) for shear bond strength test (SBS). Exposure to CS followed an adaptation of the method described by Le Mesurier. Colorimetric reading, surface morphology and roughness, SBS and adhesive remnant index (ARI) were assessed. Statistical analysis comprised independent and paired t-tests, ANOVA/Tukey and Fisher's exact tests (α = 0.05). Results: Changes were observed in brackets' color (NBS: GCE = 2.4; GCO = 1.9; GPS = 2.1), surface roughness (ΔRa: GCE = 1.1 ± 0.8 µm; GCO = 1.9 ± 1.5µm; GPS = -0.3 ± 0.1 µm / ΔRz: GCE = 1.4 ± 1.0 nm; GPS = -0.5 ± 0.1 nm); and SBS (GPS - experimental = 221.8 ± 48.6 N) after exposure to CS (p< 0.05). Conclusions: Exposure, in vitro, of aesthetic brackets to CS resulted in changes of color to darker and more opaque shades, surface roughness alterations, and higher SBS values. ARI scores were not associated with exposure to CS.

RESUMO Objetivo: O objetivo do presente estudo foi avaliar os efeitos da fumaça do cigarro (FC) nas propriedades físicas e mecânicas de braquetes cerâmicos, de policarbonato e de cerâmica de alumina. A hipótese nula testada foi de que os braquetes estéticos não seriam influenciados pela FC. Métodos: Noventa braquetes estéticos foram alocados em três grupos (n = 30): cerâmica (GCE), policarbonato (GCO) e cerâmica de alumina (GPS). Dez amostras de cada grupo foram designadas para análise de cor e rugosidade superficial, realizada antes (T0) e após (T1) exposição à FC, e vinte amostras foram alocadas nos grupos controle e experimental (n = 10) (não expostos e expostos à FC, respectivamente) para o teste de resistência ao cisalhamento (RC). A exposição à FC foi realizada de acordo com o método descrito por Le Mesurier. Leitura colorimétrica, morfologia e rugosidade de superfície, RC e índice de adesivo remanescente (ARI) foram avaliados. A análise estatística foi realizada por meio dos testes t independente e para amostras pareadas, ANOVA/Tukey e teste exato de Fisher (α = 0,05). Resultados: Foram observadas alterações na cor (NBS: GCE = 2,4; GCO = 1,9; GPS = 2,1), rugosidade superficial (ΔRa: GCE = 1,1 ± 0,8 µm; GCO = 1,9 ± 1,5 µm; GPS = -0,3 ± 0,1 µm / ΔRz: GCE = 1,4 ± 1,0 nm; GPS = -0,5 ± 0,1 nm) e RC (GPS - experimental = 221,8 ± 48,6 N) dos braquetes após exposição à FC (p< 0,05). Conclusões: A exposição in vitro de braquetes estéticos à FC resultou em mudanças na cor, para tons mais escuros e mais opacos; alterações na rugosidade superficial e maiores valores de RC. Os resultados do ARI não foram associados à exposição à FC.

Agreement among instruments of quantitative evaluation of the hard palate in children / Concordância entre instrumentos de avaliação quantitativa do palato duro em crianças

ABSTRACT Purpose To evaluate the agreement among instruments of the quantitative evaluation of hard palate. Methods This cross-sectional study was performed with a sample of 30 children aged 6 to 11 from Santa Maria, Southern Brazil. The instruments for palate measurements evaluated were: digital caliper, used directly in the oral cavity and in plaster casts, Korkhaus tridimensional bow, used directly in the oral cavity and in plaster casts, and Dolphin Imaging Software used for measurements in cone-beam computed tomography (CBCT). The agreement among different instruments was evaluated using the Intraclass Correlation Coefficient (ICC). Results The means of all transversal dimensions obtained by cone-beam computed tomography were lower than those of the other instruments - the agreement values in the width between the canines and in the width between the first molars were lower when comparing the cone-beam computed tomography and the other instruments. In the width between the first and second premolars, all comparisons showed acceptable agreement values. Good concordance values were obtained when comparing the palate depth at the second premolar region when using a bow divider inside the oral cavity and in the cast. Conclusion Most instruments presented satisfactory agreement in the measurements related to the transverse plane of the hard palate. However, when the vertical plane was evaluated, only the bow divider applied to both cast and oral cavity presented ideal agreement.

RESUMO Objetivo Avaliar a concordância entre instrumentos de avaliação quantitativa do palato duro. Método Este estudo transversal foi realizado com uma amostra de 30 crianças de 6 a 11 anos de Santa Maria, sul do Brasil. Os instrumentos de medidas do palato avaliados foram: paquímetro digital, utilizado diretamente na cavidade oral e em modelos de gesso, arco tridimensional Korkhaus, usado diretamente na cavidade oral e em modelos de gesso, e Dolphin Imaging Software utilizado para medições em tomografia computadorizada de feixe cônico (CBCT). A concordância entre os diferentes instrumentos foi avaliada por meio do Coeficiente de Correlação Intraclasse (ICC). Resultados As médias de todas as dimensões transversais obtidas pela tomografia computadorizada de feixe cônico foram menores do que as dos outros instrumentos - os valores de concordância na largura entre os caninos e na largura entre os primeiros molares foram baixos na comparação entre a tomografia computadorizada de feixe cônico e os demais instrumentos. Na largura entre o primeiro e o segundo pré-molar, todas as comparações apresentaram valores de concordância aceitáveis. Valores de concordância aceitáveis também foram obtidos ao comparar a profundidade do palato na região do segundo pré-molar com o uso de um divisor de arco dentro da cavidade oral e no gesso. Conclusão A maioria dos instrumentos apresentou concordância satisfatória nas medidas relacionadas ao plano transverso do palato duro. Porém, quando avaliado o plano vertical, apenas o divisor de arco aplicado tanto no gesso quanto na cavidade oral apresentou concordância ideal.

Does the premature loss of primary anterior teeth cause morphological, functional and psychosocial consequences?

Premature loss of primary anterior teeth in deciduous arches is a controversial topic in the literature, especially due to the lack of robust scientific evidence regarding the types and magnitudes of the consequences involved. Morphological, functional, and psychosocial problems may arise from untreated premature loss of primary incisors and canines. The morphological problems include impaction and eruption disturbances of permanent successors; inclination and/or extrusion of adjacent and antagonist teeth, respectively; midline deviation; and crowding. Functional complications, such as speech disorders, aesthetic problems, and development of non-nutritive habits may occur, resulting in psychosocial implications, including a decrease in self-esteem, and even being targeted for bullying. The current critical review aimed to present and discuss the evidence available in the literature about the etiology, characteristics, implications and interventions resulting from the premature loss of primary anterior teeth. It is of utmost importance that future studies be developed to support the clinical decisions made by dental professionals on this topic.

Does the exposure to cigarette smoke influence the colour stability and mechanical properties of different orthodontic elastic ligatures? - in vitro study.

OBJECTIVE: The aim of this study was to evaluate the colour stability and mechanical resistance of orthodontic elastic ligature exposed to cigarette smoke. METHODS: Four commercial brands were used: Aditek® (GA), Eurodonto® (GE), Morelli® (GM) and Orthometric® (GO). Eight elastic ligature rings (for mechanical analysis) and eight 5×5mm fragments of the material (for colour stability analysis) were separated from each commercial brand for the control group (C) (n=64) and experimental group (E) (n=64). The control group was not exposed to cigarette smoke. Colourimetric status (CIEL*a*b* System) and light transmittance (% transmitted light) were evaluated using Vita Easyshade Compact and CM2600 spectrophotometers, respectively. The mechanical resistance was evaluated using a universal testing machine (EMIC DL), performing tensile testing (speed 5mm/min). The analyses occurred at the following times: T0, before exposure to the smoke; T1, after the 1st exposure; and T2, after the 2nd exposure to cigarette smoke. Comparison between the groups and evaluation of the time effect were performed with the ANOVA/Tukey (a=0.05) and ANOVA-MR tests with Bonferroni correction (α=0.016). RESULTS: Significant differences were only observed for colour stability in the GA-E (NBS T2: 15.94±1.88) and GM-E (NBS T2: 16.11±4.54) groups (P<0.05); transmittance in the GA-E group (T2-T0: -9.07±5.01) (P<0.016) and mechanical resistance in the GA-C group (T2-T0: -0.95±0.61N) (P<0.016). CONCLUSION: The orthodontic elastic ligatures were sensitive to the cigarette smoke exposure regarding to loss of mechanical strength properties and change in colour stability.

Comparison of feldspathic veneer surface treatments on ceramic bracket SBS, ARI and surface roughness after different debonding/polishing methods: An in vitro study.

OBJECTIVES: To analyse, in vitro, surface properties and the shear bond strength after debonding and polishing procedures of ceramic brackets directly bonded to 0.3-0.5-mm thick feldspathic veneers. MATERIALS AND METHODS: Fifty six feldspathic ceramic veneers samples (0.3 to 0.5-mm thick) were allocated into groups according to veneers surface treatment procedures: (S) glaze layer was retained; (SHF) hydrofluoric (HF) acid etch; (SOXA) Al2O3 sandblasting; and (SB) diamond burs roughening. Specimens were treated with silane Monobond N® and ceramic brackets bonded with Transbond XT®. Shear bonding strength (SBS) was assessed with a universal testing machine and ARI evaluated under a stereomicroscopic coupled to a digital camera. Remaining bonding composite was removed using a porcelain polishing kit and surface roughness assessed with a stylus profilometer. RESULTS: No statistically significant differences were identified for SBS among the study groups (S, SHF, SOXA and SB) (P>0.05). The majority of the specimens presented ARI scores 3 and 2 (P>0.05). All of the study groups presented increased surface roughness after debonding and polishing procedures (P<0.05), with significant greater values observed in SB group (RaF: 1.27±0.41; RzF: 6.23±1.82), (P<0.05). CONCLUSIONS: Surface treatment with hydrofluoric acid etch, Al2O3 sandblasting and diamond bur did not enhance SBS of orthodontic brackets bonded to ceramic veneers. Ceramic surfaces treated with diamond burs presented significantly increased roughness after adhesive removal.

Agreement among instruments of quantitative evaluation of the hard palate in children.

PURPOSE: To evaluate the agreement among instruments of the quantitative evaluation of hard palate. METHODS: This cross-sectional study was performed with a sample of 30 children aged 6 to 11 from Santa Maria, Southern Brazil. The instruments for palate measurements evaluated were: digital caliper, used directly in the oral cavity and in plaster casts, Korkhaus tridimensional bow, used directly in the oral cavity and in plaster casts, and Dolphin Imaging Software used for measurements in cone-beam computed tomography (CBCT). The agreement among different instruments was evaluated using the Intraclass Correlation Coefficient (ICC). RESULTS: The means of all transversal dimensions obtained by cone-beam computed tomography were lower than those of the other instruments - the agreement values in the width between the canines and in the width between the first molars were lower when comparing the cone-beam computed tomography and the other instruments. In the width between the first and second premolars, all comparisons showed acceptable agreement values. Good concordance values were obtained when comparing the palate depth at the second premolar region when using a bow divider inside the oral cavity and in the cast. CONCLUSION: Most instruments presented satisfactory agreement in the measurements related to the transverse plane of the hard palate. However, when the vertical plane was evaluated, only the bow divider applied to both cast and oral cavity presented ideal agreement.

In-vitro trabecular bone damage following mono- and bicortical mini implants anchorage in mini-implant assisted rapid palatal expansion (MARPE).

OBJECTIVES: To assess in-vitro trabecular bone damage following mono- and bicortical mini-implant (MI) anchorage in mini-implant assisted rapid palatal expansion (MARPE). MATERIAL AND METHODS: Sixteen self-drilling MI (four MARPE appliances) were distributed in two groups according to bone insertion (monocortical and bicortical) in bovine rib. The device was activated five times (0.5mm each). Trabecular bone damage was assessed using micro-CT scans made at baseline and after each activation by trabecular spacing parameter (Tb.Sp) (distance [mm] between the trabecular bone structure). These measurements were made in five different regions of interest (ROI) surrounding the screw (whole, superior, inferior, anterior and posterior). Two-way ANOVA with Tukey post-hoc analysis (α=0.05) was used to evaluate the effect of insertion type (monocortical vs. bicortical) and activation cycle (0-5) on trabecular damage. The time effect was evaluated using ANOVA-MR test effect with Bonferroni correction (α=0.003). The micro-CT images were also examined qualitatively. RESULTS: When analysing the individual ROIs, only the superior ROI had a significant difference (P<0.003) beginning at the fourth activation cycle. For the monocortical group, trabecular spacing was affected when the whole ROI was analysed beginning at the fourth activation cycle, while for the superior ROI, this difference became apparent beginning with the third activation cycle (P<0.003). For the qualitative analysis, it seems that only monocortical anchorage influences the trabecular bone in the superior area. CONCLUSIONS: Monocortical anchorage is more susceptible to bone damage around the MIs, with the superior (cervical) region most strongly affected.

Miniscrew-assisted rapid palatal expansion (MARPE): how to achieve greater stability. In vitro study.

OBJECTIVE: Assess the influence of mono- and bicortical anchorage and diameter of mini-implants (MIs) on the primary stability of these devices. METHODS: 60 self-drilling MIs were distributed in six groups according to diameter (1.5mm, 1.8mm or 2.0mm) and type of anchorage (monocortical and bicortical) in bovine rib. The primary stability was evaluated by insertion torque, micromobility and pull-out strength tests. ANOVA and/or Tukey analysis were used to conduct intergroup comparisons (p< 0.05). Non-parametric statistics (Kruskal-Wallis and Mann-Whitney) were performed when normality was not found (p< 0.05). RESULTS: MIs with larger diameters and bicortical anchorage showed greater primary stability regarding insertion torque (p< 0.05) and micromobility (p< 0.05). Only MI diameter had an effect on the pull-out strength test. Larger diameter MIs presented better retention in pull-out strength tests (p< 0.001), regardless of mono- or bicortical anchorage. CONCLUSIONS: MI primary stability is dependent on its diameter and type of anchorage. Bicortical anchorage showed greater stability when compared with monocortical anchorage, independently of other variables.

Are temporomandibular disorders associated with facial asymmetry? A systematic review and meta-analysis.

OBJECTIVE: To assess scientific evidence of the association between temporomandibular joint (TMJ) disorders and facial asymmetry (FA). METHODS: A systematic review was performed in accordance with the PRISMA checklist. A search strategy was developed in electronic databases including MEDLINE, Scopus, Web of Science, Virtual Health Library and Cochrane Library until January 2020. Eligibility criteria included observational studies that investigated the occurrence of FA among patients with and without signs and symptoms of TMJ disorders. Risk of bias of individual studies was analysed after study selection and data collection processes according to Fowkes and Fulton guidelines. Four meta-analyses (MA) were performed to evaluate the association between TMJ disorders and linear/angular menton deviation, subgrouping the studies into unilateral and bilateral cases. The evidence was certainty-tested using the GRADE approach. RESULTS: The search retrieved 2371 studies, 31 of which were eligible for full-text reading. Seven cross-sectional clinical studies met the eligibility criteria and were included in the qualitative synthesis, comprising a total of 621 subjects (345 with TMJ disease and 276 in control group), four of which were classified as being methodologically sound. Five studies were eligible for quantitative synthesis. Linear and angular menton deviation was greater in individuals with unilateral TMJ disorders than controls (MD = 2.41 [0.33, 4.50] P = .02; I2  = 86% and MD = 2.68 [0.99, 4.38] P = .002; I2  = 0%, respectively). CONCLUSIONS: Despite the low certainty in evidence, the present study indicated that unilateral TMJ disorders are associated with FA. However, longitudinal studies with greater certainty of evidence should be conducted to achieve a stronger estimate of this association.