Frequency and variability of nonmetric dental crown traits of primary and permanent molars in a group of orthodontic patients.

BACKGROUND: The present study aimed to assess the frequency and variation of 13 nonmetric dental crown traits (NDCT) in permanent and primary molars in German orthodontic patients. METHODS: Dental records from orthodontic patients were screened and evaluated. First and second permanent and primary upper and lower molars (from left and right sides) were assessed. Teeth with cavitated dental caries, occlusal wear, restorations and obvious dental deformities were not evaluated. The NDCT for permanent molars were identified and scored according to the odontoscopic system developed by Arizona State University Dental Anthropology System (ASUDAS). The NDCT for primary molars were identified and scored according to ASUDAS, Hanihara's method and Sciulli's method. The χ2 test was used to investigate side preference and sexual dimorphism at a significance level of p ≤ 0.050. RESULTS: A total of 163 orthodontic patients (82 males and 81 females) aged 8-14 years were included. A sexual dimorphism was observed for the hypocone in first upper permanent molar (p = 0.041). The protostylid was observed in lower permanent molars (range 2.1-10%). Males presented more hypoconulid than females (p = 0.019). Only females presented the distal trigonid crest in lower first permanent molars (p = 0.002). The most common groove pattern in primary molars was Y; male presented more Y grade than females in the lower second primary molar (p = 0.039). Asymmetry was observed in some traits, ranging from 0 to 100%. CONCLUSION: The present study showed the frequency of NDCT of molars in German orthodontic patients and demonstrated that some traits present sexual dimorphism.

Correction: The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

[This corrects the article DOI: 10.1371/journal.pone.0288782.].

Mandibular and dental measurements for sex determination using machine learning.

The present study tested the combination of mandibular and dental dimensions for sex determination using machine learning. Lateral cephalograms and dental casts were used to obtain mandibular and mesio-distal permanent teeth dimensions, respectively. Univariate statistics was used for variables selection for the supervised machine learning model (alpha = 0.05). The following algorithms were trained: logistic regression, gradient boosting classifier, k-nearest neighbors, support vector machine, multilayer perceptron classifier, decision tree, and random forest classifier. A threefold cross-validation approach was adopted to validate each model. The areas under the curve (AUC) were computed, and ROC curves were constructed. Three mandibular-related measurements and eight dental size-related dimensions were used to train the machine learning models using data from 108 individuals. The mandibular ramus height and the lower first molar mesio-distal size exhibited the greatest predictive capability in most of the evaluated models. The accuracy of the models varied from 0.64 to 0.74 in the cross-validation stage, and from 0.58 to 0.79 when testing the data. The logistic regression model exhibited the highest performance (AUC = 0.84). Despite the limitations of this study, the results seem to show that the integration of mandibular and dental dimensions for sex prediction would be a promising approach, emphasizing the potential of machine learning techniques as valuable tools for this purpose.

Exploring the sex-associated differences in molars fused roots.

BACKGROUND: Human sexual dimorphism is associated with many biological characteristics, including dental variables. OBJECTIVES: To investigate if molars fused roots present sex-associated differences. METHODS: Panoramic radiographs were used to investigate the frequency and distribution of permanent molars fused roots. Only patients with all first and second permanent molars were included. Third molars were not investigated. Any molar with roots fused apical to the usual furcal position were considered molar fused roots. Comparisons between males and females were performed using chi-square or Fisher's and Mann-Whitney tests and the established alpha was 5% (p<0.05). Sex-differential liability models were also proposed. RESULTS: A total of 84 males and 86 females were included and 1360 molars were analyzed. Among them, 46 (26.06%) present at least one molar with fused root. Second maxillary molars were the most affected teeth. There was an association between sex and molars with fused roots. Females had a 3.4 higher chance to present fused roots than males (OR=3.4, CI 95% 1.6-6.8; p=0.0008). The female: male ratio of molars with fused roots was 2.5:1. The number of molars with fused roots ranged from 1 to 6 per patient, and the mean number of Females presented more molars with fused roots (mean = 1.01; standard deviation = 1.52) than males (mean = 0.31; standard deviation = 0.85) (p<0.05). CONCLUSIONS: Molar fused root of permanent teeth presents sex-associated differences, in which females are more affected than males. Our results support sex-differential liability models for molars fused roots.

Investigation of polymorphisms in BMP2, BMP4, SMAD6 and RUNX2 genes and pulp stones.

This study aimed to assess the association between genetic polymorphisms in BMP2 (rs1005464 and rs235768), BMP4 (rs17563), SMAD6 (rs2119261 and rs3934908) and RUNX2 (rs59983488 and rs1200425) and pulp stones (PS). A total of 117 participants, consisting of 63 individuals with PS and 54 without PS, were included. Digital radiographs and a demographic/clinical questionnaire were used. Genomic DNA from salivary cells was genotyped via real-time polymerase chain reaction. Statistical analyses, including Chi-Square, Fisher's exact tests, Poisson regression and dimensionality reduction, were conducted. The rs2119261 polymorphism in the SMAD6 gene showed an association with genotype distribution in the recessive model (p = 0.049). The T-T haplotype in the SMAD6 gene (rs2119261 and rs3934908) was more prevalent in the control group and significantly linked with PS (p = 0.029). No associations were found between PS risk and genetic polymorphisms in BMP2, BMP4 and RUNX2. Polymorphisms in the SMAD6 gene were associated with PS.

BMP2 rs1005464 is associated with mandibular condyle size variation.

This study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in endochondral development-related genes and mandibular condyle shape, size, volume, and symmetry traits. Cone-beam Computed Tomographies and genomic DNA from 118 individuals were evaluated (age range: 15-66 years). Data from twelve 3D landmarks on mandibular condyles were submitted to morphometric analyses including Procrustes fit, principal component analysis, and estimation of centroid sizes and fluctuating asymmetry scores. Condylar volumes were additionally measured. Seven SNPs across BMP2, BMP4, RUNX2 and SMAD6 were genotyped. Linear models were fit to evaluate the effect of the SNPs on the mandibular condyles' quantitative traits. Only the association between BMP2 rs1005464 and centroid size remained significant after adjusting to account for the false discovery rate due to multiple testing. Individuals carrying at least one A allele for this SNP showed larger condylar size than common homozygotes GG (ß = 0.043; 95% CI: 0.014-0.071; P value = 0.028). The model including BMP2 rs1005464, age and sex of the participants explained 17% of the variation in condylar size. Shape, volume, and symmetry were not associated with the evaluated SNPs. These results suggest that BMP2 rs1005464 might be associated with variation in the mandibular condyles size.

Exploring the association between PITX2, third molars agenesis and sella turcica morphology : PITX2, third molars agenesis and sella turcica morphology.

OBJECTIVES: PITX2 is required for mammalian development and single nucleotide polymorphisms (SNPs) in this gene could be involved in dental agenesis and sella turcica patterns. Thus, the present study evaluated the association between SNPs in PITX2, third molars agenesis and sella turcica phenotypes. MATERIALS AND METHODS: The sample consisted of healthy orthodontic German patients with lateral cephalometric radiographs with clearly visualization of the sella turcica, and dental orthopantomograms. The morphological variations of the sella turcica were evaluated using the lateral cephalograms, while third molar agenesis was evaluated using orthopantomograms. DNA isolated from buccal cells was used for genotyping three SNPs in PITX2 (rs3796902, rs1947187, and rs2595110). The analyzes were performed using a significance of 5%. There was no association between third molar agenesis and sella turcica phenotypes (p > 0.05). SNPs in PITX2 were also not associated with third molars agenesis (p > 0.05). RESULTS: SNPs in PITX2 were associated with sella turcica phenotypes. The rs3796902 was associated with hypertrophic posterior clinoid process (p = 0.013). The rs1947187 and rs2595110 were associated with sella turcica bridge type A (p = 0.013 and p = 0.011, respectively for genotype distribution). Patients that carry the genotypes GG-CC-AG (rs3796902- rs1947187- rs2595110) had 7.2 higher chance to present sella turcica bridge type A (p = 0.002; Odds ratio = 7.2, Confidence interval 95% 2.04-27.04). CONCLUSIONS: Third molar agenesis was not associated with SNPs in PITX2 and sella turcica phenotypes. SNPs in PITX2 may have an important role in sella turcica pattern.

Prevalence of orofacial injuries resulting from trauma in individuals with cerebral palsy: A systematic review and meta-analysis.

Individuals with cerebral palsy (CP) may have cognitive, sensitive, behavioral, communicative, and convulsive disorders. Because defensive reflexes are reduced by CP, the risk of orofacial trauma is greater in these individuals. This study aimed to evaluate the prevalence of orofacial injuries resulting from trauma in patients with CP. This review was reported according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) and registered in the International Prospective Register of Systematic Reviews (PROSPERO-CRD42022293570). The search was performed for articles published until January 2023 in Embase, Latin American and Caribbean Literature on Health Sciences (LILACS), PubMed/Medline, Scopus, and Web of Science databases. Gray literature was also consulted through Google Scholar, OpenGrey, ProQuest Dissertations, and Theses. Studies in which orofacial injuries due to trauma were prevalent in individuals with CP were included. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Tool. Additionally, a random-effects meta-analysis was conducted. Twelve studies were included in the synthesis, of which nine presented a low risk of bias and three presented a moderate risk. When considering the general prevalence of orofacial injuries in patients with CP, a prevalence of 34% [95% CI = 18%-52%; I2 = 98%] was observed, with enamel and dentin fractures being the most common orofacial injuries. Approximately one in three patients with CP showed at least one type of orofacial injury involving dental trauma. There is a lack of literature assessing the prevalence of these traumas in soft tissues and the evidence for this outcome remains uncertain.

Estrogen deficiency influences SEC23A gene expression in the odontogenic region of incisors ­ a murine model study / A deficiência de estrógeno influencia a expressão gênica de SEC23A na região odontogênica de incisivos ­ um estudo em modelo murino

Recent scientific evidence suggests a close relationship between estrogen deficiency and vitamin D- related genes. Estrogen and vitamin D were involved with alterations in odontogenesis and tooth eruption process. Objective: The aim of the present study was to evaluate the influence of estrogen deficiency on the expression of genes related to the activation and degradation of vitamin D in the odontogenic region of incisors in a murine model. Material and Methods: This is an experimental clinical study that used female Wistar Hannover rats. The animals were randomly divided into two groups according to the intervention received: Hypoestrogenism Group ­ animals submitted to estrogen deficiency by ovariectomy surgery and Control Group ­ animals submitted to sham surgery. Surgical intervention was performed in the prepubertal period; the animals were followed throughout the pubertal period. After euthanasia, the hemimandibles were removed to evaluate the mRNA expression of the vitamin D-related genes AMDHD1, CYP24A1, NADSYN1 and SEC23A in the odontogenic region of incisors through real time PCR. Student's t test was used to compare means. Kruskal-Wallis test and Dunn's posttest were also used. The level of significance was 5%. Results: SEC23A was overexpressed in the estrogen deficiency condition in the odontogenic region (p=0.021). Conclusion: Estrogen deficiency may influence the expression of the SEC23A gene involved in the activation and degradation of vitamin D in the odontogenic region of incisors in a murine model(AU)

Evidências científicas recentes sugerem uma estreita relação entre a deficiência de estrógeno e os genes relacionados à vitamina D. O estrógeno e a vitamina D estão envolvidos com alterações na odontogênese e no processo de erupção dentária. Objetivo: O objetivo do presente estudo foi avaliar a influência da deficiência de estrógeno na expressão de genes relacionados à ativação e degradação da vitamina D na região odontogênica de incisivos em modelo murino. Material e Métodos: Trata-se de um estudo clínico experimental que utilizou ratas Wistar Hannover fêmeas. Os animais foram divididos aleatoriamente em dois grupos de acordo com a intervenção recebida: Grupo Hipoestrogenismo ­ animais submetidos à deficiência de estrógeno pela cirurgia de ovariectomia e Grupo Controle ­ animais submetidos à cirurgia simulada. A intervenção cirúrgica foi realizada no período pré-púbere; os animais foram acompanhados durante todo o período puberal. Após a eutanásia, as hemimandíbulas foram removidas para avaliar a expressão de mRNA dos genes AMDHD1, CYP24A1, NADSYN1 e SEC23A, relacionados à vitamina D, na região odontogênica de incisivos por meio de PCR em tempo real. O teste t de Student foi utilizado para comparar as médias. Também foram utilizados o teste de Kruskal-Wallis e o pós-teste de Dunn. O nível de significância foi de 5%. Resultados: SEC23A foi superexpresso na condição de deficiência de estrógeno na região odontogênica (p=0,021). Conclusão: A deficiência de estrógeno pode influenciar a expressão do gene SEC23A envolvido na ativação e degradação da vitamina D na região odontogênica de incisivos em modelo murino (AU)

Non-syndromic supernumerary teeth and association with a self-reported family history of cancer.

BACKGROUND: Supernumerary teeth are an alteration of dental developmental and result in the formation of teeth above the usual number. Epidemiologic studies suggested that patients with dentofacial anomalies and their family members may present an increased risk of developing cancer, including female breast cancer and gynecologic cancers. These observations indicate that genetic alterations that result in dental anomalies may be related to cancer development. Thus, the aim of the present study was to evaluate the association between supernumerary teeth and a family history of female breast cancer and gynecologic cancers. METHODS: The diagnosis of supernumerary teeth was based on clinical and radiographic examinations. For data collection, a questionnaire asking for information regarding ethnicity, age, gender, and self-reported family history of cancer up to the second generation was used. Statistical analysis was performed using the Χ2 test and Fisher's exact test with an established α of 5%. RESULTS: A total of 344 patients were included; 47 of them had one or more non-syndromic supernumerary teeth (not associated with any syndrome or cleft lip and palate) and 297 were control patients. Age, ethnicity, and gender distribution were not statistically different between the group with supernumerary teeth and the control group (p > 0.05). The supernumerary teeth were most commonly observed in the incisors area. Breast cancer (n = 17) was the most commonly self-reported type of cancer, followed by uterine cervical (n = 10), endometrial (n = 2), and ovarian (n = 1) cancers. Endometrial cancer was significantly associated with the diagnosis of supernumerary teeth (p = 0.017). CONCLUSION: This study suggests that patients with supernumerary teeth possess a higher risk of having family members with endometrial cancer.

Investigating the association between dental age and polymorphisms in genes encoding estrogen receptors.

BACKGROUND: Genetic polymorphisms have been shown to influence several physiological traits, including dental and craniofacial characteristics. Understanding the clinical relevance of genetic polymorphisms in dental practice is crucial to personalize treatment plans and improve treatment outcomes. OBJECTIVE: to evaluate the association between dental age and genetic polymorphisms in genes encoding estrogen receptors alpha and beta (ESR1 and ESR2, respectively) in a sample of Brazilian children. METHODOLOGY: This retrospective cross-sectional study was performed with children undergoing orthodontic treatment. Patients with syndromes, congenital anomalies, craniofacial deformities, under hormonal or systemic treatment, and with a previous history of facial trauma were excluded. Panoramic radiographs were used to assess dental age according to the Demirjian, Goldstein, and Tanner method. A delta [dental age-chronological age (DA-CA)] was obtained, which shows whether the patient tends to have a normal, delayed (negative values), or advanced (positive values) dental age. DNA isolated from buccal cells was used to genotype four genetic polymorphisms: rs9340799 (A>G) and rs2234693 (C>T), located in ESR1; and rs1256049 (C>T) and rs4986938 (C>T), located in ESR2. A statistical analysis was performed and values of p<0.05 indicated statistical difference. RESULTS: A total of 79 patients were included, 44 (55.70%) girls and 35 (44.30%) boys. The Demirjian, Goldstein, and Tanner method, in general, overestimated patients' age by 0.75 years. There was no difference in the delta of dental age between the sexes (p>0.05). Genetic polymorphisms in ESR1 and ESR2 were not associated with dental age (p>0.05). CONCLUSION: The studied genetic polymorphisms in ESR1 and ESR2 were not associated with dental age in Brazilian children.

Evaluation of Endo 10 mobile application as diagnostic tool in endodontics.

Background: Endodontic diagnosis can be compared to a puzzle, requiring the interpretation of a series of clinical and imaging data. Mobile health, especially mobile application (apps), can assist professionals in endodontic diagnosis. This work aims to evaluate an app - Endo 10 app, designed to assist pulpal and periapical diagnosis based on the patient's signs and symptoms and radiographic data. Material and Methods: A total of 41 dental students and dentists with different levels of expertise (10 multi-specialty clinic professors, 17 residents in endodontics and 14 dental students) were included. The System Usability Scale (SUS) was used to evaluate usability and the Davis' technology acceptance model was used to evaluate usefulness of Endo 10 app. The Mann-Whitney test was performed to compare SUS scores between professors and undergraduate dental students and to compare questions 6 and 7 of the utility test and verify whether participants who understood that the technology was useful also better understood the concepts of endodontic diagnosis. The agreement between professor's diagnosis with the app and professor without the app, and between professor and residents in endodontics with the app were evaluated. Results: The SUS score at the 50th percentile was 77.5, graded as acceptable. No significant difference was observed in the SUS scores when analyzing professors and dental students separately (p = 0.442). Usefulness test showed positive responses ranging between 72% - 100%. No statistically significant difference was observed between questions 6 and 7 of the utility test (p = 0.206), indicating that the group of participants who understood that the technology was useful in endodontic diagnosis was associated with the agreement that the application helped to better understand the concepts related. The diagnosis agreement between professor in the common diagnosis process and professor with app was 100% (31) of cases. The concordance between professor and residents in endodontics with the app was 71% (22) of cases. The differences were associated with resident's misinterpreting the patient's data. Conclusions: The Endo 10 app reached the usability and usefulness requirements. It proved accurate in diagnosing pulpal and periapical pathologies. Key words:Dental education, endodontics, diagnosis, smartphone, dental informatics.

Single nucleotide polymorphisms in inducible nitric oxide synthase gene are not associated with persistent apical periodontitis.

The aim of this study was to investigate whether there is an association between inducible in single nucleotide polymorphisms in nitric oxide synthase (rs2297518 and rs2779249) and persistent apical periodontitis. A total of 291 Brazilian subjects were included: 125 with signs/symptoms of persistent apical periodontitis and 166 with root canal-treated teeth exhibiting healthy perirradicular tissues. Endodontically treated patients were followed up after 1 year. The two single nucleotide polymorphisms in nitric oxide synthase were analysed using real-time polymerase chain reaction. Chi-square test and odds ratio with 95% confidence intervals were performed to compare genotype distributions between 'healed' and 'persistent apical periodontitis' groups (p < 0.05). Logistic regression analysis was used to evaluate SNP-SNP interactions. The allele and genotype distributions for the polymorphisms between the persistent apical periodontitis and healed groups were not statistically significant (p > 0.05). In the logistic regression analysis, the polymorphisms were not associated with persistent apical periodontitis and SNP-SNP interactions.

The luminous transmittance of the quartz-glass fiber posts is superior to glass fiber posts.

Fiber-reinforced prefabricated intraarticular posts have gained popularity due to several favorable characteristics for clinical use compared to metallic intraradicular posts. AIM: To evaluate the light transmission capacity of two types of fiber posts, using two different methods. MATERIALS AND METHOD: The posts were divided into two groups: experimental group - quartz-glass fiber posts (n=10) and control group - glass fiber posts (n=10). The light transmittance of the samples was compared by means of light intensity test by photographs and ultraviolet-visible spectrophotometer. This test was analyzed by thirds: coronal, middle, and apical. The spectophotometer tested the luminous transmittance along the length of the post. The statistical analysis was conducted with a significance level of 0.05. RESULTS: Light transmission was 97% on the coronal third, 68% in the middle third, and 27.66% in the apical third in the posts of the experimental group. In the posts of the control group, the light transmission was 95.33% in the coronal third, 80.66% in the middle third, and 41.33% in the apical third. Light transmission was significantly higher in the middle third of the posts of the experimental group when compared to the control group (p<0.05). The luminous transmittance of the posts of the experimental group was 97.4% with wavelengths of 400 nm, 97% at 450 and 500 nm, and 96.9% at 550 nm. In the posts of the control group, the luminous transmittance was 72.3% with wavelengths of 400 nm, 68.6% at 450 nm; 64.6% at 500 nm and 61.5% at 550 nm. The posts of the experimental group demonstrated significantly higher light transmittance than the control group (p<0.001).

Os pinos intra-articulares pré-fabricados reforçados com fibras têm ganhado popularidade devido a várias características favoráveis ao uso clínico em comparação com os pinos intra-radiculares metálicos). Objetivo: Avaliar a capacidade de transmissão de luz de dois tipos de pinos de fibra, usando dois métodos diferentes. Materiais e Método: Os pinos foram divididos em dois grupos: grupo experimental - pinos de fibra de vidro de quartzo e grupo controle - pinos de fibra de vidro. A transmitância de luz das amostras foi comparada por meio de teste de intensidade de luz por fotografias e espectrofotômetro ultravioleta-visível. Este teste foi analisado por terços: coronal, médio e apical. O espectrofotômetro testou a transmitância luminosa ao longo do comprimento do pino. A análise estatística foi realizada com nível de significância de 0,05. Resultados: A transmissão luminosa foi de 97% no terço coronal, 68% no terço médio e 27,66% no terço apical nos pinos do grupo experimental. Nos pinos do grupo controle, a transmissão de luz foi de 95,33% no terço coronal, 80,66% no terço médio e 41,33% no terço apical. A transmissão luminosa foi significativamente maior no terço médio dos pinos do grupo experimental quando comparado ao grupo controle (p<0,05). A transmitância luminosa dos pinos do grupo experimental foi de 97,4% com comprimento de onda de 400 nm, 97% em 450 e 500 nm e 96,9% em 550 nm. Nos postes do grupo controle, a transmitância luminosa foi de 72,3% com comprimento de onda de 400 nm, 68,6% em 450 nm; 64,6% a 500 nm e 61,5% a 550 nm. Os pinos do grupo experimental demonstraram transmitância de luz significativamente maior do que o grupo controle (p<0,001). Conclusão: a transmitância luminosa dos pinos de fibra de vidro de quartzo é maior do que pinos de fibra de vidro.

The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

The aim of this study is to evaluate if single nucleotide polymorphisms (SNPs) in WNT6 and WNT10A are associated with the risk of dental pulp calcification in orthodontic patients. This cross-sectional study followed the "Strengthening the Reporting of Genetic Association Studies" (STREGA) guidelines. Panoramic radiographs (pre- and post-orthodontic treatment) and genomic DNA from 132 orthodontic patients were studied. Dental pulp calcification (pulp stones and/or pulp space narrowing) was recorded in upper and lower first molars. The SNPs in WNT6 and WNT10A (rs7349332, rs3806557, rs10177996, and rs6754599) were assessed through genotyping analysis using DNA extracted from buccal epithelial cells. The association between pulp calcification and SNPs were analyzed using allelic and genotypic distributions and haplotype frequencies (p<0.05). Prevalence of dental pulp calcification was 42.4% in the 490 studied molars. In the genotypic analysis, the SNPs in WNT10A showed a statistically significant value for molar calcification (p = 0.027 for rs1017799), upper molar calcification (p = 0.040 for rs1017799) (recessive model), and molar calcification (p = 0.046 for rs3806557) (recessive model). In the allelic distribution, the allele C of the SNP rs10177996 in WNT10A was associated with molar calcifications (p = 0.042) and with upper first molar calcification (p = 0.035). Nine combinations of haplotypes showed statistically significant value (p<0.05). The findings of this study indicates that SNPs in WNT10A and WNT6 are associated with dental pulp calcification in molars after orthodontic treatment and may be considered as biomarkers for dental pulp calcification.

The luminous transmittance of the quartz-glass fiber posts is superior to glass fiber posts / Superioridade da transmitância luminosa dos pinos de fibra de quartzo

ABSTRACT Fiber-reinforced prefabricated intraarticular posts have gained popularity due to several favorable characteristics for clinical use compared to metallic intraradicular posts. Aim: To evaluate the light transmission capacity of two types of fiber posts, using two different methods. Materials and Method: The posts were divided into two groups: experimental group - quartz-glass fiber posts (n=10) and control group - glass fiber posts (n=10). The light transmittance of the samples was compared by means of light intensity test by photographs and ultraviolet-visible spectrophotometer. This test was analyzed by thirds: coronal, middle, and apical. The spectophotometer tested the luminous transmittance along the length of the post. The statistical analysis was conducted with a significance level of 0.05. Results: Light transmission was 97% on the coronal third, 68% in the middle third, and 27.66% in the apical third in the posts of the experimental group. In the posts of the control group, the light transmission was 95.33% in the coronal third, 80.66% in the middle third, and 41.33% in the apical third. Light transmission was significantly higher in the middle third of the posts of the experimental group when compared to the control group (p<0.05). The luminous transmittance of the posts of the experimental group was 97.4% with wavelengths of 400 nm, 97% at 450 and 500 nm, and 96.9% at 550 nm. In the posts of the control group, the luminous transmittance was 72.3% with wavelengths of 400 nm, 68.6% at 450 nm; 64.6% at 500 nm and 61.5% at 550 nm. The posts of the experimental group demonstrated significantly higher light transmittance than the control group (p<0.001). Conclusion: the luminous transmittance of quartz-glass fiber posts is higher than glass fiber posts.

RESUMO Os pinos intra-articulares pré-fabricados reforçados com fibras têm ganhado popularidade devido a várias características favoráveis ao uso clínico em comparação com os pinos intra-radiculares metálicos). Objetivo: Avaliar a capacidade de transmissão de luz de dois tipos de pinos de fibra, usando dois métodos diferentes. Materiais e Método: Os pinos foram divididos em dois grupos: grupo experimental - pinos de fibra de vidro de quartzo e grupo controle - pinos de fibra de vidro. A transmitância de luz das amostras foi comparada por meio de teste de intensidade de luz por fotografias e espectrofotômetro ultravioleta-visível. Este teste foi analisado por terços: coronal, médio e apical. O espectrofotômetro testou a transmitância luminosa ao longo do comprimento do pino. A análise estatística foi realizada com nível de significância de 0,05. Resultados: A transmissão luminosa foi de 97% no terço coronal, 68% no terço médio e 27,66% no terço apical nos pinos do grupo experimental. Nos pinos do grupo controle, a transmissão de luz foi de 95,33% no terço coronal, 80,66% no terço médio e 41,33% no terço apical. A transmissão luminosa foi significativamente maior no terço médio dos pinos do grupo experimental quando comparado ao grupo controle (p<0,05). A transmitância luminosa dos pinos do grupo experimental foi de 97,4% com comprimento de onda de 400 nm, 97% em 450 e 500 nm e 96,9% em 550 nm. Nos postes do grupo controle, a transmitância luminosa foi de 72,3% com comprimento de onda de 400 nm, 68,6% em 450 nm; 64,6% a 500 nm e 61,5% a 550 nm. Os pinos do grupo experimental demonstraram transmitância de luz significativamente maior do que o grupo controle (p<0,001). Conclusão: a transmitância luminosa dos pinos de fibra de vidro de quartzo é maior do que pinos de fibra de vidro.

Prevalence and local causes for retention of primary teeth and the associated delayed permanent tooth eruption.

BACKGROUND: This study aimed to evaluate the prevalence of retained primary teeth (RPT) associated with delayed permanent tooth eruption and the factors associated with this condition in German children. METHODS: This is a cross-sectional retrospective study that evaluated panoramic radiographs from orthodontic patients. The diagnosis of RPT was established according to Nolla developmental stage. The primary tooth was considered retained when its successor permanent tooth was in Nolla stage 8, 9, or 10. Statistical analysis was performed with an α of 5% (p < 0.05). RESULTS: A total of 102 children (48 girls and 54 boys), and 574 primary teeth and their respective permanent successor teeth were evaluated. We classified 192 teeth as RPT. Sixty-one (59.8%) children presented one or more RPT. Gender was not significantly different between RPT and control teeth (p = 0.838; odds ratio 0.95, confidence interval 95% 0.44-2.16). In the majority of the RPT cases (68.7%), no clear cause to explain the prolonged retention was identified. The pathological problems most commonly observed with RPT were dental fillings (19.3%), followed by dental caries (4.6%), and ectopic tooth eruption (2.1%). CONCLUSIONS: The incidence of RPT associated with delayed permanent tooth eruption in German children was high and the most common pathological condition associated with RPT was dental caries.

Variation of Tooth Crown Size in Cleft Lip and Palate Patients.

AIM: This study aims to compare the mesiodistal (MD) and buccolingual (BL) tooth crown size (TCS) of adult patients with cleft lip and palate (CL/P) and patients without CL/P. MATERIALS AND METHODS: The sample of this study consisted of 146 adult patients, of both genders, of which 73 were included in the case group (with CL/P) and 73 were included in the control group (without CL/P). Data regarding gender and age and cleft type were collected. In addition, dental models were evaluated to obtain the TCS in the maximum distance of the MD and BL dimensions of all erupted permanent teeth (except third molars). The results were submitted to statistical analysis with a significance level of 0.05. RESULTS: In the upper arch, the central incisors (CI) were smaller in the case group for the MD and BL dimensions (p < 0.05). The lateral incisors (LI) and canine (C) were smaller only in the BL width (p < 0.05) and the second molars (SM), were smaller only in the MD dimensions. In the lower arch, there were significant differences only in the BL width between groups, the CI and LI presented smaller measurements in CL/P patients, while the left first molar (FM) and right first premolar (FPM) were larger (p < 0.05) than in patients without CL/P. CONCLUSION: Patients with CL/P have different sizes in certain teeth compared to patients without CL/P. CLINICAL RELEVANCE: Cleft lip and palate patients usually present important dental anomalies; thereby, the knowledge about trends in tooth size variations in CL/P patients can aid in dental and orthodontic treatment planning to obtain a stable, functional, and esthetic occlusion.

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.

Effect of genetic polymorphisms rs2301113 and rs2057482 in the expression of HIF-1α protein in periodontal ligament fibroblasts subjected to compressive force.

OBJECTIVE: Many genes and signaling molecules are involved in orthodontic tooth movement, with mechanically and hypoxically stabilized HIF-1α having been shown to play a decisive role in periodontal ligament signaling during orthodontic tooth movement. Thus, this in vitro study aimed to investigate if genetic polymorphisms in HIF1A (Hypoxia-inducible factor α-subunits) influence the expression pattern of HIF-1α protein during simulated orthodontic compressive pressure. METHODOLOGY: Samples from human periodontal ligament fibroblasts were used and their DNA was genotyped using real time Polymerase chain reaction for the genetic polymorphisms rs2301113 and rs2057482 in HIF1A . For cell culture and protein expression experiments, six human periodontal ligament fibroblast cell lines were selected based on the patients' genotype. To simulate orthodontic compressive pressure in fibroblasts, a 2 g/cm2 force was applied under cell culture conditions for 48 hours. Protein expression was evaluated by Western Blot. Paired t-tests were used to compare HIF-1α expression with and without compressive pressure application and unpaired t-tests were used to compare expression between the genotypes in rs2057482 and rs2301113 (p<0.05). RESULTS: The expression of HIF-1α protein was significantly enhanced by compressive pressure application regardless of the genotype (p<0.0001). The genotypes in the genetic polymorphisms rs2301113 and rs2057482 were not associated with HIF-1α protein expression (p>0.05). CONCLUSIONS: Our study confirms that compressive pressure application enhances HIF-1α protein expression. We could not prove that the genetic polymorphisms in HIF1A affect HIF-1α protein expression by periodontal ligament fibroblasts during simulated orthodontic compressive force.