Microbial contamination profile on esthetic elastomeric ligatures through the checkerboard DNA-DNA hybridization technique : A randomized split-mouth study.

OBJECTIVE: The aim of this study is to assess the microbial contamination of three different brands of esthetic elastomeric ligatures. MATERIALS AND METHODS: Different brands of esthetic ligatures (Unistick Pearl [American Orthodontics, Sheboygan, WI, USA], Power Sticks Pearl [Ortho Technology, Tampa, FL, USA], and Ease [Obscure, 3M Unitek, Monrovia, CA, USA]) were randomly assigned to permanent canines of 25 patients (aged 11-18 years) undergoing corrective orthodontic treatment. After 30 days, the ligatures were removed, processed, and the biofilm composition was analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species. The microbiological data were analyzed using a nonparametric mixed model. RESULTS: The ligatures presented intense microbial contamination after 30 days, but no statistically significant differences were observed among the three groups (p > 0.05). The levels of the evaluated individual species and proportions of the microbial complexes showed no statistically significant differences among the ligature groups (p > 0.05). CONCLUSIONS: Esthetic elastomeric ligatures became multicolonized by several bacterial species after 30 days of exposure to the oral cavity. However, no relevant differences were observed among the biofilm composition formed on the different ligature brands.

Maxillary alveolar bone evaluation following dentoalveolar expansion with clear aligners in adults: A cone-beam computed tomography study.

Objective: To investigate the effects of maxillary orthodontic expansion on the alveolar bone tissue in adult patients treated with aligners by using cone-beam computed tomography. Methods: Thirty patients (22 females and 8 males; mean age: 36.3 years) were treated with Invisalign® aligners. Cone-beam computed tomography and digital models were obtained before (T0) and after (T1) upper arch expansion. The bone thicknesses in the cervical, middle, and apical areas of the incisors, canines, premolar, and first molars were buccally and palatally measured, totaling 96 areas and 2,880 measurements. The buccolingual inclinations and transverse measurements of the teeth were obtained from digital models to correlate them with the bone changes. The statistical tests used were Student's t-test, analysis of variance, and Pearson's correlation tests (p < 0.05). Results: From the 96 areas evaluated, 84 revealed an increase or stability in the alveolar bone thickness and twelve displayed significant bone loss. Bone changes did not correlate with the tooth inclination and transverse measurements. Conclusions: Within the limitation of the present study, mild levels of upper arch expansion obtained with Invisalign® aligners in adult patients did not result in any clinically significant loss of alveolar bone thickness.

Impact of genetic variations in the WNT family members and RUNX2 on dental and skeletal maturation: a cross-sectional study.

BACKGROUND: This study evaluated if genetic variations in the WNT family members and RUNX2 are associated with craniofacial maturation, investigating dental and skeletal maturity in children and teenagers. METHODS: Radiographs from pre-orthodontic treatment of Brazilian patients (7 to 17 years-old) were used to assess dental (panoramic radiographs) and skeletal maturity (cephalometric radiographs). The chronological age (CA) was calculated based on the date of birth and the time the radiographs were performed. For the dental maturity analysis, the Demirjian (1973) method was used and a delta [dental age - chronological age (DA-CA)] was calculated. For the skeletal maturity analysis, the Baccetti et al. (2005) method was used and the patients were classified as "delayed skeletal maturation", "advanced skeletal maturation" or "normal skeletal maturation". DNA isolated from buccal cells was used for genotyping of two genetic variations in WNT family genes: rs708111 (G > A) in WNT3A and rs1533767 (G > A) in WNT11; and two genetic variations in RUNX2: rs1200425 (G > A) and rs59983488 (G > T). A statistical analysis was performed and values of p < 0.05 indicated a significant difference. RESULTS: There were no associations between dental maturity and genotypes (p > 0.05). In the skeletal maturity analysis, the allele A in the rs708111 (WNT3A) was statistically more frequent in patients with delayed skeletal maturation (Prevalence Ratio = 1.6; 95% Confidence Interval = 1.00 to 2.54; p-value = 0.042). CONCLUSIONS: The rs708111 in the WNT3A gene impacts on skeletal maturation.

In vitro study of structural and mechanical properties of latex and non-latex intermaxillary orthodontic elastics.

PURPOSE: We evaluated bacterial endotoxin adhesion, superficial micromorphology and mechanical properties of latex and non-latex intermaxillary orthodontic elastics. METHODS: To quantify the adhered bacterial endotoxin, elastics were divided into 5 groups: experimental (n = 12) latex and non-latex elastics, previously contaminated by an endotoxin solution, negative control (n = 6) latex and non-latex elastics without contamination, and positive control (n = 6) stainless steel specimens (metallic replicas), contaminated by an endotoxin solution. In parallel, the structural micromorphology (n = 6) and surface roughness of latex and non-latex intermaxillary orthodontic elastics were assessed using confocal laser microscopy. Force degradation (g) and deformation of the internal diameter change (mm) were also evaluated. Structural micromorphology, surface roughness (µm), force degradation (g) and internal diameter (mm) change were evaluated at time 0 and after 24 and 72 h in a deformation test. Data were analyzed by the Shapiro-Wilk, Kruskal-Wallis, Dunn, ANOVA and Bonferroni tests (α = 5%). RESULTS: Endotoxin adhered similarly to both types of elastics with scores of 3 (> 1.0 EU/mL). The surface microstructure of both types of elastics showed irregularities and porosities at all times. Initially, the latex elastics had a higher surface roughness (p < 0.001) than the non-latex ones. After 24 h loading, surface roughness of the latex elastics was significantly reduced (p < 0.001), while after 72 h, the values were similar for both types (p > 0.05). The non-latex elastics had significantly higher force generation values (p < 0.05) at 0, 24 and 72 h compared with the latex elastics, although there was a significant reduction (p < 0.001) in force over time for both elastics. Despite similar initial values, non-latex elastics had a significantly larger internal diameter (p < 0.001) after the loading periods of 24 and 72 h compared with the latex elastics. CONCLUSION: Both elastics showed high affinity with endotoxin and microstructural irregularities of their surface. The non-latex elastics generated higher force values but demonstrated greater deformation of the internal diameter after loading.

Alveolar defects before and after surgically assisted rapid palatal expansion (SARPE): a CBCT assessment.

INTRODUCTION: Surgically Assisted Rapid Palatal Expansion (SARPE) promote maxillary expansion in skeletally mature patients. This technique is effective; however, some side effects are still unknown. OBJECTIVES: evaluate the presence of alveolar defects (dehiscences and fenestrations) in patients submitted to the SARPE. The null hypothesis tested was: SARPE does not influence the number of dehiscences and fenestrationss. METHODS: A retrospective quasi-experiment study of a convenience sample of 279 maxillary teeth, in 29 patients evaluated with Cone Beam Computed Tomography (CBCT) at T1 (before SARPE), T2 (after expansion) and T3 (after retention), was performed. The examined teeth were: canines, first and second premolars, first and second molars. in axial, coronal, and cross-sectional views. The evaluations involved viewing slices from mesial to distal of the buccal roots. RESULTS: All statistical analyses were performed using SAS 9.3 and SUDAAN softwares. Alpha used in the study was 0.05. Alveolar defects increased statistically from T1 (69.0%) to T2 (96.5%) and T3 (100%). Dehiscences increased 195% (Relative Risk 2.95) at the end of expansion (T2). After retention (T3), individuals were on average 4.34 times more likely to develop dehiscences (334% increase). Fenestrations did not increase from T1 to T2 (p = 0.0162, 7.9%) and decreased from T2 to T3 (p = 0.0259, 4.3%). Presence of fenestrations at T1 was a significant predictor for the development of dehiscences in T2 and T3. Dehiscences increased significantly in all teeth, except second molars. CONCLUSION: The null hypothesis was rejected. After SARPE the number of dehiscences increased and fenestrations decreased. Previous alveolar defects were predictor for dehiscences after SARPE.

Effects of ionizing radiation and different resin composites on shear strength of ceramic brackets: an in vitro study.

INTRODUCTION: Head and neck cancer is considered one of the most common types, and its treatment includes radiotherapy, which can trigger side effects and undesirable sequelae in the oral cavity and dental tissues. OBJECTIVE: This study aimed to make an in vitro evaluation of the shear strength and failure mode of ceramic orthodontic brackets bonded with two different composites in enamel submitted to ionizing radiation. METHODS: After the study was approved by the Research Ethics Committee, 60 healthy human premolars were selected and divided into two groups, based on the absence or presence of ionizing irradiation of the enamel. The fragments were thermocycled and then randomly subdivided into two subgroups, according to the composite used for bonding the ceramic brackets (Inspire Ice - Ormco) to the enamel (n = 15): Transbond XT composite (3M), and Light Bond composite (Reliance). After 24 hours, the specimens were submitted to the shear strength test, and the failure mode was analyzed using a stereomicroscope and confocal microscopy. The shear strength data were submitted to two-way ANOVA, considering a significance level of 5%. RESULTS: The groups submitted to radiation presented lower shear strength values (4.48MPa) than those not irradiated (9.23MPa) (p< 0.001), and the tested composites were not statistically different (p= 0.078). Regarding the fracture mode, all the groups presented mostly adhesive fractures. CONCLUSION: It was concluded that ionizing radiation negatively affects the adhesion of ceramic brackets, regardless of the composite used for bonding.

Association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone / Relação entre a influência da gravidade da apneia obstrutiva do sono e alterações craniofaciais e do posicionamento do osso hioide

Abstract Introduction The association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone is still scarcely addressed in the literature. Objective To evaluate whether the intensity of obstructive sleep apnea is associated with craniofacial alterations and the position of the hyoid bone in children with mixed dentition. Methods 76 children aged 7 to 10 years old were examined by otorhinolaryngological evaluation, polysomnography, and orthodontic assessment, including cephalometry. The participants were divided in 3 groups: primary snoring, mild obstructive sleep apnea and moderate to severe obstructive sleep apnea. Cephalometric measures of the face and hyoid bone were assessed. These measures were compared among the different groups by unpaired Student's t test. Moreover, these measures were correlated with the patient's obstructive apnea and hypopnea index variable using Pearson's correlation test. Results Of the 76 children, 14 belonged to group 1, with primary snoring; 46 to group 2, with mild obstructive sleep apnea; and 16 to group 3, with moderate-severe obstructive sleep apnea. There was no difference between the groups regarding the craniofacial variables. Children with obstructive sleep apnea showed a longer distance from the hyoid bone to the mandibular plane when compared to the primary snoring group (p < 0.05). Between the two obstructive sleep apnea subgroups, patients with moderate or severe disease showed significantly shorter horizontal distance between the hyoid bone and the posterior pharyngeal wall (p < 0.05), when compared to the groups with mild obstructive sleep apnea. We also observed a significant positive correlation between obstructive apnea and hypopnea index and the distance from the hyoid to the mandibular plane (p < 0.05) as well as a significant negative association between obstructive apnea and hypopnea index and the horizontal distance from the hyoid to the posterior pharyngeal wall (p < 0.01). Conclusion We did not observe any association between obstructive sleep apnea and linear lateral alterations of the face. In contrast, there is a direct association between obstructive sleep apnea severity and the inferior and posterior position of the hyoid bone in children aged 7 to 10 years old.

Resumo Introdução A relação entre a intensidade da apneia obstrutiva do sono e alterações esqueléticas da face e do hioide em crianças é pouco explorada na literatura. Objetivo Avaliar se a intensidade da apneia obstrutiva do sono correlaciona-se às alterações craniofaciais e ao posicionamento do osso hioide em crianças em fase de dentição mista. Método Foram submetidas 76 crianças entre 7 e 10 anos à avaliação otorrinolaringológica, polissonografia e avaliação ortodôntica, inclusive cefalometria. Os participantes foram divididos em 3 grupos: grupo 1 com ronco primário, grupo 2 com apneia obstrutiva do sono leve e grupo 3 com apneia obstrutiva do sono moderada/grave. Foram analisadas medidas cefalométricas da face e do osso hioide. Essas medidas foram comparadas entre si dentro dos diferentes grupos por teste t de Student não pareado. Além disso, essas medidas foram correlacionadas com a variável índice de apneias obstrutivas e hipopneias do paciente através do teste de correlação de Pearson. Resultados Das 76 crianças, 14 constituíram o grupo 1, ronco primário; 46 o grupo 2, apneia obstrutiva do sono leve; e 16 o grupo 3, apneia obstrutiva do sono moderada/grave. Não se observou diferença significante entre os grupos para as variáveis craniofaciais. Observou-se maior distância do osso hioide ao plano mandibular nos dois grupos com apneia obstrutiva do sono quando comparado ao ronco primário (p < 0,05). Entre os dois subgrupos da apneia obstrutiva do sono, os pacientes com doença moderada ou grave apresentaram distância horizontal entre o hioide e a parede posterior da faringe significantemente menor (p < 0,05), quando comparados aos grupos com apneia obstrutiva do sono leve. Observamos ainda correlação significantemente positiva entre índice de apneias obstrutivas e hipopneias e a distância do hioide ao plano mandibular (p < 0,05) e significantemente negativa entre índice de apneias obstrutivas e hipopneias e distância horizontal do hioide com a parede posterior da faringe (p < 0,01). Conclusão Não observamos relação da apneia obstrutiva do sono com alterações lineares laterais da face. Em contraste, existe relação direta entre a gravidade da apneia obstrutiva do sono e a posição inferior e posterior do osso hioide em crianças entre 7 e 10 anos.

Surgically assisted rapid palatal expansion (SARPE): three-dimensional superimposition on cranial base.

OBJECTIVES: To evaluate dental and skeletal changes caused by surgically assisted rapid palatal expansion (SARPE) using the superimposition of three-dimensional cone-beam computed tomography (CBCT) images on the cranial base. MATERIAL AND METHODS: This is a retrospective quasi-experiment before-and-after study using a convenience sample. Twenty-four adult patients (13 male and 11 female) were evaluated before SARPE (T0), immediately after expansion (T1), and after 6 months of retention (T2). CBCT scans were superimposed on the anterior cranial base using voxel-based registration. Measurements from different reference points were used for comparisons between times. RESULTS: At T1, all teeth had significant buccal tipping. At T2, most teeth remained in the same position as at T1, except the first premolar and the first molar, whose buccal roots moved slightly. The amount of bony expansion was 65 to 70% of the amount of tooth movement. The A point and maxillary incisors moved anteriorly from T0 to T1 and T2 (p < 0.0001). Inter-nasal distance had increased significantly at T1 (p < 0.0001) and remained stable at T2 (p = 0.478). No expansion was achieved at the zygomatic arch (p = 0.114). CONCLUSION: SARPE promoted substantial buccal tipping of posterior teeth and some bone displacement; it also moved the maxilla and teeth forward and increased nasal width. CLINICAL RELEVANCE: No other clinical studies have evaluated dental and skeletal changes caused by SARPE using superimposition of 3D CBCT images on the cranial base. This study findings may help clinical dentists plan treatments using safe and reliable information.

Orthodontic mini-implants: clinical and peri-implant evaluation.

The study evaluated the clinical changes of orthodontic mini-implants (MI) inserted for the purpose of anchoring during orthodontic treatment. The null hypotheses were: 1-that there is no correlation between proximity of the MI to the root and peri-implantitis or mobility; 2-that peri-implantitis does not interfere with mobility; 3-that the pain is not related to mobility or peri-implantitis. Forty (40) patients were selected and the MI were evaluated for each patient. MI in the upper and lower arch were evaluated for a period of approximately 6 months with relationship to the distance MI - root, peri-implantitis, mobility, biological damage and pain through the analysis of periapical radiography and clinical/periodontal evaluation. The evaluations were performed out by means of scores and a correlation was made between the variables. No statistically significant differences were found between the upper and lower arch in the variables evaluated, except for the mobility that was more present in the lower arch (p = 0.0336). There was a correlation between peri-implantitis and mobility (p = 0.0003) and between pain and mobility (p = 0.0443). However, there was no correlation between a greater degree of peri-implantitis and greater mobility (p = 0.7054). In addition, the MI placed too close to the root showed peri-implantitis (p = 0.0142). The null hypotheses were rejected because there was a positive correlation between the analyzes. The placement of MI close to the root led to greater peri-implantitis. Patients who reported pain had greater mobility of the MI and peri-implantitis led to greater mobility.

The effect of whitening toothpastes on polyurethane and silicone orthodontic clear ligatures: A clinical study.

BACKGROUND: This study aimed to verify the effects of bleaching toothpaste on colour stability, elastic properties, surface topography between aesthetic polyurethane and silicone elastomeric ligatures from different brands. METHODS: Elastomeric ligatures tested were: 1-Mini Single Case Ligature Stick (RMO-polyurethane); 2-Ligature "S" Shaped Dispenser (RMO-Silicone); 3-Sany-tie (GAC-translucent polyurethane); and 4-Sili-tie (GAC-translucent silicone). The ligatures were randomly assigned from the brackets of canines and lower incisors of 40 patients. The study had two phases of 30 days in which a different toothpaste was used, followed by a washout period of 30 days. After each phase, ligatures were submitted to colour checking, tensile strength, and SEM. RESULTS: The average of the ultimate tensile strength (m = 2.59; DP = 0.014) was higher in the control ligatures if compared to the tested ones (m = 2.24; DP = 0.014). There were no statistically significant differences between toothpastes regarding the type of ligature. Also, no interaction was observed between toothpastes in ligature's ultimate tensile strength and strain. The type of toothpaste did not minimize colour changes. CONCLUSION: In conclusion, there was no difference in colour stability and elastic properties between polyurethane or silicone aesthetic elastomeric modules. Whitening toothpastes had no impact on ligatures performance after 30 days in the oral cavity.

Effect of vomer position following surgically assisted rapid palatal expansion.

PURPOSE: To evaluate the effect of vomer position and prevalence of periodontal dehiscence in patients who underwent surgically assisted rapid palatal expansion (SARPE). The null hypotheses were the following: (1) vomer position in the coronal plane does not influence the degree of skeletal and dental expansion; and (2) there is no association between expansion, periodontal dehiscence and vomer position. METHODS: Twenty-one patients were evaluated before treatment (T0) and immediately after SARPE expansion (T1). After SARPE, the vomer was in the right side in 11 patients and in the left in 10 patients. Skeletal and dental effects were evaluated using CBCT, landmarks and measurements. RESULTS: The maxilla and the nasal cavity expanded asymmetrically. The side containing the vomer had less skeletal expansion but more dental tipping. Dehiscence increased significantly from T0 to T1 and was associated with the amount of skeletal displacement, especially when greater than 3.20 mm. In the first premolars region, there was more than 2 mm of asymmetric expansion observed in 38.5% of the patients. CONCLUSION: The null hypotheses were rejected. The side containing the vomer had less skeletal expansion of the maxilla and nasal cavity but more dental tipping. Dehiscence increased after expansion, but there were no differences between sides.

Association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone.

INTRODUCTION: The association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone is still scarcely addressed in the literature. OBJECTIVE: To evaluate whether the intensity of obstructive sleep apnea is associated with craniofacial alterations and the position of the hyoid bone in children with mixed dentition. METHODS: 76 children aged 7 to 10 years old were examined by otorhinolaryngological evaluation, polysomnography, and orthodontic assessment, including cephalometry. The participants were divided in 3 groups: primary snoring, mild obstructive sleep apnea and moderate to severe obstructive sleep apnea. Cephalometric measures of the face and hyoid bone were assessed. These measures were compared among the different groups by unpaired Student's t test. Moreover, these measures were correlated with the patient's obstructive apnea and hypopnea index variable using Pearson's correlation test. RESULTS: Of the 76 children, 14 belonged to group 1, with primary snoring; 46 to group 2, with mild obstructive sleep apnea; and 16 to group 3, with moderate-severe obstructive sleep apnea. There was no difference between the groups regarding the craniofacial variables. Children with obstructive sleep apnea showed a longer distance from the hyoid bone to the mandibular plane when compared to the primary snoring group (p<0.05). Between the two obstructive sleep apnea subgroups, patients with moderate or severe disease showed significantly shorter horizontal distance between the hyoid bone and the posterior pharyngeal wall (p<0.05), when compared to the groups with mild obstructive sleep apnea. We also observed a significant positive correlation between obstructive apnea and hypopnea index and the distance from the hyoid to the mandibular plane (p<0.05) as well as a significant negative association between obstructive apnea and hypopnea index and the horizontal distance from the hyoid to the posterior pharyngeal wall (p<0.01). CONCLUSION: We did not observe any association between obstructive sleep apnea and linear lateral alterations of the face. In contrast, there is a direct association between obstructive sleep apnea severity and the inferior and posterior position of the hyoid bone in children aged 7 to 10 years old.

Effects of ionizing radiation and different resin composites on shear strength of ceramic brackets: an in vitro study

ABSTRACT Introduction: Head and neck cancer is considered one of the most common types, and its treatment includes radiotherapy, which can trigger side effects and undesirable sequelae in the oral cavity and dental tissues. Objective: This study aimed to make an in vitro evaluation of the shear strength and failure mode of ceramic orthodontic brackets bonded with two different composites in enamel submitted to ionizing radiation. Methods: After the study was approved by the Research Ethics Committee, 60 healthy human premolars were selected and divided into two groups, based on the absence or presence of ionizing irradiation of the enamel. The fragments were thermocycled and then randomly subdivided into two subgroups, according to the composite used for bonding the ceramic brackets (Inspire Ice - Ormco) to the enamel (n = 15): Transbond XT composite (3M), and Light Bond composite (Reliance). After 24 hours, the specimens were submitted to the shear strength test, and the failure mode was analyzed using a stereomicroscope and confocal microscopy. The shear strength data were submitted to two-way ANOVA, considering a significance level of 5%. Results: The groups submitted to radiation presented lower shear strength values (4.48MPa) than those not irradiated (9.23MPa) (p< 0.001), and the tested composites were not statistically different (p= 0.078). Regarding the fracture mode, all the groups presented mostly adhesive fractures. Conclusion: It was concluded that ionizing radiation negatively affects the adhesion of ceramic brackets, regardless of the composite used for bonding.

Alveolar defects before and after surgically assisted rapid palatal expansion (SARPE): a CBCT assessment

ABSTRACT Introduction: Surgically Assisted Rapid Palatal Expansion (SARPE) promote maxillary expansion in skeletally mature patients. This technique is effective; however, some side effects are still unknown. Objectives: evaluate the presence of alveolar defects (dehiscences and fenestrations) in patients submitted to the SARPE. The null hypothesis tested was: SARPE does not influence the number of dehiscences and fenestrationss. Methods: A retrospective quasi-experiment study of a convenience sample of 279 maxillary teeth, in 29 patients evaluated with Cone Beam Computed Tomography (CBCT) at T1 (before SARPE), T2 (after expansion) and T3 (after retention), was performed. The examined teeth were: canines, first and second premolars, first and second molars. in axial, coronal, and cross-sectional views. The evaluations involved viewing slices from mesial to distal of the buccal roots. Results: All statistical analyses were performed using SAS 9.3 and SUDAAN softwares. Alpha used in the study was 0.05. Alveolar defects increased statistically from T1 (69.0%) to T2 (96.5%) and T3 (100%). Dehiscences increased 195% (Relative Risk 2.95) at the end of expansion (T2). After retention (T3), individuals were on average 4.34 times more likely to develop dehiscences (334% increase). Fenestrations did not increase from T1 to T2 (p = 0.0162, 7.9%) and decreased from T2 to T3 (p = 0.0259, 4.3%). Presence of fenestrations at T1 was a significant predictor for the development of dehiscences in T2 and T3. Dehiscences increased significantly in all teeth, except second molars. Conclusion: The null hypothesis was rejected. After SARPE the number of dehiscences increased and fenestrations decreased. Previous alveolar defects were predictor for dehiscences after SARPE.

RESUMO Introdução: A expansão rápida da maxila assistida cirurgicamente (ERMAC) promove expansão em pacientes esqueleticamente maduros. Essa técnica é efetiva; entretanto, alguns efeitos colaterais ainda são desconhecidos. Objetivos: Avaliar a presença de defeitos alveolares (deiscência e fenestração) em pacientes submetidos à ERMAC. A hipótese nula testada foi que a ERMAC não influenciaria o número de deiscências e fenestrações. Métodos: Foi realizado um estudo quase-experimental de uma amostra de conveniência de 279 dentes superiores, de 29 pacientes que foram avaliados por meio de tomografia computadorizada de feixe cônico (TCFC) em T1 (antes da ERMAC), T2 (após expansão) e T3 (após contenção). Caninos, primeiros e segundos pré-molares, primeiros e segundos molares foram examinados em cortes axiais, coronais e sagitais. As raízes vestibulares desses dentes foram avaliadas da face mesial até a distal. Resultados: Todas as análises estatísticas foram realizadas usando os softwares SAS 9.3 e SUDAAN. O alfa usado no estudo foi de 0,05. Os defeitos alveolares aumentaram significativamente de T1 (69,0%) para T2 (96,5%) e T3 (100%). Deiscências aumentaram 195% (risco relativo de 2,95%) no final da expansão (T2). Após contenção (T3), os pacientes tiveram, em média, 4,34 vezes mais chance de desenvolver deiscência (334% de aumento). As fenestrações não aumentaram de T1 para T2 (p= 0.0162, 7.9%) e diminuíram de T2 para T3 (p = 0.0259, 4,3%). A presença de fenestrações em T1 foi um preditor significativo para o desenvolvimento de deiscências em T2 e T3. Deiscências aumentaram significativamente em todos os dentes, exceto nos segundos molares. Conclusão: A hipótese nula foi rejeitada. Após a ERMAC, o número de deiscências aumentou e o de fenestrações diminuiu. Defeitos alveolares prévios foram preditores de deiscências após a ERMAC.

Streptococcus mutans adherence to conventional and self-ligating brackets: an in vitro study.

INTRODUCTION: Although self-ligating brackets presumably provide better hygiene conditions, no consensus has been reached so far. OBJECTIVE: Therefore, the objective of this study was to evaluate, in an in vitro experimental design, the adherence of Streptococcus mutans (SM) in self-ligating and conventional brackets of different manufacturers and ligature types. METHODS: Four commercial brands of maxillary premolar metal brackets were tested (Abzil®; Morelli®; 3M Unitek®; and GAC®). Each one was subdivided into three groups, which varied according to the type of ligature and bracket model (metallic, elastic, and self-ligating), totalizing twelve groups, composed of six brackets each. Previously sterilized brackets were initially immersed in saliva for one hour, and subsequently washed and added in a bacterial suspension, maintained in aerobiosis for 72 hours. The adhered bacteria were then separated and quantified by colony forming units (CFU/mL) counting after 48 hours of growth. The groups were compared by Kruskal-Wallis and Dunn post-hoc tests (p< 0.05). RESULTS: Regardless of the commercial brand, self-ligating brackets had significantly less CFU/mL. However, according to comparisons performed within each commercial brand, only Abzil® self-ligating brackets had significantly lower biofilm adhesion. Among all of the self-ligating models, GAC® brackets presented the highest bacterial adhesion rate. CONCLUSIONS: Self-ligating brackets are likely to present lower rates of biofilm adhesion. Particularly, Abzil® and GAC® self-ligating brackets are less likely to accumulate biofilm. Although such results are derived from an in vitro study, practitioners might acknowledge findings concerning bacterial adhesion as one of the relevant features to be considered during bracket selection.

Hepatotoxicity in Patients with Hepatocellular Carcinoma on Treatment with Immune Checkpoint Inhibitors.

Risk factors for hepatic immune-related adverse events (HIRAEs) in patients with advanced/unresectable hepatocellular carcinoma (HCC) treated with immune checkpoint inhibitors (ICIs) are unclear. We investigated: (i) clinical and morpho-pathological predictors of HIRAEs in 27 pretreatment tumor specimens, including surrogate biomarkers of the HCC immune class (based on intratumoral tertiary lymphoid structures, and glutamine synthase, CD3, and CD79 expression); and (ii) the relationship between HIRAE onset and subsequent treatment outcomes. Fifty-eight patients were included-20 (34%) received ICIs alone, and 38 (66%) received ICIs plus targeted agents as first- or further-line treatment. After a median time of 0.9 months (range, 0.4-2.7), nine patients (15.5%) developed grade ≥ 3 hepatitis, which was significantly associated with higher baseline ALT levels (p = 0.037), and an infectious HCC etiology (p = 0.023). ICIs were safely resumed in six out of nine patients. Time to treatment failure (TTF) was not significantly different in patients developing grade ≥ 3 hepatitis vs. lower grades (3.25 vs. 3.91 months, respectively; p = 0.81). Biomarker surrogates for the HCC immune class were not detected in patients developing grade ≥ 3 hepatitis. Grade ≥ 3 hepatitis has a benign course that does not preclude safe ICI reintroduction, without any detrimental effect on TTF.

CO2 laser irradiation for debonding ceramic orthodontic brackets.

This study evaluated shear bond strength (SBS), adhesive remnant index (ARI) and fracture mode of chemically and mechanically retained ceramic brackets bonded with different composite resins and irradiated with CO2 laser. The null hypothesis was that ceramic brackets bonded with different composite resins and irradiated with CO2 laser would have similar SBS values. Ninety human premolars were divided into four experimental groups according to the combination of type of composite resin (Transbond XT and Z 250) and type of ceramic bracket (Fascination and Mystique), and two control groups (n=15). In the four experimental groups, the brackets were irradiated with CO2 laser at 10 W for 3 seconds before SBS testing. Enamel surface ARI was calculated after debonding under electron microscopy scanning. ANOVA and the Mann-Whitney test were used for statistical analysis. The laser groups had lower SBS values than the non-irradiated groups (control) (p<0.05). The mechanically retained brackets (Mystique) had the higher (p<0.05) and Z250 had the lower SBS values after CO2 laser irradiation. The groups bonded with Z250 had the highest ARI. Adhesive fractures were the most prevalent. The null hypothesis was rejected. CO2 laser decreased SBS efficiently and facilitated debonding of mechanically and chemically retained ceramic brackets.

Effectiveness of Invisalign® aligners in the treatment of severe gingival recession: A case report.

In this report, we demonstrate the effectiveness of the InvisalignⓇ system in the treatment of severe gingival recession and bone dehiscence through torque, translation, and intrusion movements in a young woman. Cone-beam computed tomography was used to assess bone parameters and check the teeth during treatment. The root of the mandibular right central incisor, which was buccally positioned and exhibited bone dehiscence of 9.4 mm, was moved toward the center of the alveolar process by using the InvisalignⓇ system and SmartForceⓇ features. The patient was monitored by a periodontist throughout the orthodontic treatment period. Her gingival recession reduced, while the bone dehiscence reduced from 9.40 mm to 3.14 mm. Thus, movement of the root into the alveolus promoted bone neoformation and treated the gingival recession. The findings from this case suggest that orthodontic treatment using the InvisalignⓇ system, along with periodontal monitoring, can aid in the treatment of gingival recession and alveolar defects.

Rapid Palatal Expansion and Utilization of E-space in Mixed Dentition: Mechanics that Helps in the Corrective Orthodontic Treatment.

AIM AND OBJECTIVE: The objective of this article was to report two clinical cases, showing the benefits of interceptive treatment using rapid palatal expansion (RPE) and the preservation of E-space. BACKGROUND: It is important to follow-up child throughout its development to detect irregularities in their occlusion and to avoid or attenuate orthodontic treatments in the future. Posterior crossbite and transverse maxillary deficiency can easily be corrected by RPE that enhances the width of the maxilla and promotes a gain of space in the arch. Another way to gain space in the arch is by using the E-space, which is the difference between the mesiodistal distance of the second primary molar in relation to the second premolar. This additional space can be used to resolve negative, mild, or moderate crowding. CASE DESCRIPTIONS: Two clinical cases that presented malocclusions due to lack of space and maxillary deficiency, along with clinical technic of how the RPE and E-space can be used to bring those patients back to normality. CONCLUSION: We concluded that with a right diagnosis, correct interceptive timing, and using what growth provides, the development can be reestablished. CLINICAL SIGNIFICANCE: The clinical importance of this report is that RPE and E-space are efficient interceptive orthodontic treatments to correct skeletal posterior crossbite (SPC) and gain space in dental arches. HOW TO CITE THIS ARTICLE: Lopes BKB, Scheicher GV, Matsumoto MAN, et al. Rapid Palatal Expansion and Utilization of E-space in Mixed Dentition: Mechanics that Helps in the Corrective Orthodontic Treatment. Int J Clin Pediatr Dent 2021;14(1):133-139.

Periodontal ligament repair after active splinting of replanted dogs' teeth.

BACKGROUND/AIM: The high rate of root resorption resulting from tooth replantation represents a serious clinical problem. In order to prevent ankylosis and replacement resorption, the contemporary literature highlights the importance of using a flexible stabilization for traumatized teeth. For this purpose, orthodontic devices may be promising for obtaining a better prognosis and periodontal repair. The aim of this study was to evaluate the effect of an active splinting protocol with controlled force in dog's teeth following replantation. MATERIAL AND METHODS: Sixty premolar roots from three dogs were used. They were submitted to endodontic treatment, hemisected, atraumatically extracted and subsequently replanted. They were divided into four groups: Passive Stabilization (n = 20)-after 20 min in a dry medium; Active Stabilization (n = 20)-after 20 min in a dry medium; Negative control (n = 10)-immediate replantation and passive Stabilization; and Positive control (n = 10)-90 min of extra-alveolar time and passive Stabilization. The samples were collected and submitted to histologic processing. They were then evaluated for the count of inflammatory cells, expression of neurotrophin 4, osteoclasts, apoptotic cells and collagen fibres. The results were submitted to ANOVA or Kruskal-Wallis statistical tests followed by Tukey or Dunn post-tests (α = 5%). RESULTS: Passive Stabilization with orthodontic brackets without traction used after replantation had the highest number of inflammatory cells (p = .0122), osteoclasts (p = .0013) and percentage of collagen fibres in the periodontal ligament (p < .0001) when compared to Active Stabilization with orthodontic brackets applying amild tensile force. Neurotrophin 4 had no statistically significant difference (p = .05), regardless of the treatment. The apoptotic cells count revealed statistical differences (p < .0001) between Active Stabilization (189.70 ± 47.99) and Positive Control (198.90 ± 88.92) when compared to Passive Stabilization (21.19 ± 32.94). CONCLUSION: The active splinting protocol using orthodontic appliances generating a light and controlled force favoured periodontal ligament repair of replanted teeth.