Genetic disturbances during dental development influence variation of number and shape of the dentition. In this study, we tested if genetic variation in enamel formation genes is associated with molar-incisor hypomineralization (MIH), also taking into consideration caries experience. DNA samples from 163 cases with MIH and 82 unaffected controls from Turkey, and 71 cases with MIH and 89 unaffected controls from Brazil were studied. Eleven markers in five genes [ameloblastin (AMBN), amelogenin (AMELX), enamelin (ENAM), tuftelin (TUFT1), and tuftelin-interacting protein 11 (TFIP11)] were genotyped by the TaqMan method. Chi-square was used to compare allele and genotype frequencies between cases with MIH and controls. In the Brazilian data, distinct caries experience within the MIH group was also tested for association with genetic variation in enamel formation genes. The ENAM rs3796704 marker was associated with MIH in both populations (Brazil: p=0.03; OR=0.28; 95% C.I.=0.06–1.0; Turkey: p=1.22e–012; OR=17.36; 95% C.I.=5.98–56.78). Associations between TFIP11 (p=0.02), ENAM (p=0.00001), and AMELX (p=0.01) could be seen with caries independent of having MIH or genomic DNA copies of Streptococcus mutans detected by real time PCR in the Brazilian sample. Several genes involved in enamel formation appear to contribute to MIH.

Despite some evidence of genetic and environmental factors on molar-incisor hypomineralization (MIH), its aetiology remains unclear. This family-based genetic association study aimed more comprehensively to investigate the genetic carriage potentially involved in MIH development. DNA was obtained from buccal cells of 391 individuals who were birth family members of 101 Brazilian nuclear families. Sixty-three single nucleotide polymorphisms (SNPs) were investigated in 21 candidate genes related to amelogenesis using the TaqMan™ OpenArray™ Genotyping platform. All SNPs were genotyped in 165 birth family members unaffected by MIH, 96 with unknown MIH status and 130 affected individuals (50.7% with severe MIH). Association analysis was performed by the transmission/disequilibrium test (TDT), and statistical results were corrected using the false discovery rate. Significant results were obtained for SNPs rs7821494 (FAM83H gene, OR = 3.7; 95% CI = 1.75-7.78), rs34367704 (AMBN gene, OR = 2.7; 95% CI = 1.16-6.58), rs3789334 (BMP2 gene, OR = 2.9; 95% CI = 1.34-6.35), rs6099486 (BMP7 gene, OR = 2.2; 95% CI = 1.14-4.38), rs762642 (BMP4 gene, OR = 2.3; 95% CI = 1.38-3.65), rs7664896 (ENAM gene, OR = 2.1; 95% CI = 1.19-3.51), rs1711399 (MMP20 gene, OR = 0.4; 95% CI = 0.20-0.72), rs1711423 (MMP20 gene, OR = 2.1; 95% CI = 1.18-3.61), rs2278163 (DLX3 gene, OR = 2.8; 95% CI = 1.26-6.41), rs6996321 (FGFR1 gene, OR = 2.7; 95% CI = 1.20-5.88), and rs5979395 (AMELX gene, OR = 11.7; 95% CI = 1.63-84.74). Through this family-based association study, we concluded that variations in genes related to amelogenesis were associated with the susceptibility to develop MIH. This result is in agreement with the multifactorial idea of the MIH aetiology, but further studies are necessary to investigate more thoroughly the factors that could influence MIH.

The aim of this study was to investigate the segregation patterns of molar incisor hypomineralization (MIH) in families, given the evidence that its etiology is influenced by genetics. Clinically, MIH may be detected in parents and/or siblings of MIH-affected children. Our study included children with at least one first permanent molar affected by MIH (proband) and their first-degree relatives (parents and siblings). The participants were examined clinically to detect MIH, according to the European Academy of Paediatric Dentistry criteria (2003). A total of 101 nuclear families (391 individuals) were studied. Proband diagnosis was followed by MIH classification of the subject, his parents and siblings, as affected, unaffected, or unknown. Segregation analysis was performed using the multivariate logistic regression model of the Statistical Analysis for Genetic Epidemiology package, and segregation models (general transmission, environmental, major gene, dominant, codominant and recessive models). The Akaike information criterion (AIC) was used to evaluate the most parsimonious model. In all, 130 affected individuals, 165 unaffected individuals, and 96 unknown individuals were studied. Severe MIH was found in 50.7% of the cases. A segregation analysis performed for MIH revealed the following different models: environmental and dominance (p = 0.05), major gene (p = 0.04), codominant (p = 0.15) and recessive models (p = 0.03). According to the AIC values, the codominant model was the most parsimonious (AIC = 308.36). Our results suggest that the codominant model could be the most likely for inheriting MIH. This result strengthens the evidence that genetic factors, such as multifactorial complex defect, influence MIH.

Objective This study aimed to evaluate the daytime sleepiness and sleep quality of students in different academic years of the dental school program. Materials and Methods A total of 221 students, from the 1st to the 5th year, answered the questionnaires: Epworth, Pittsburg, Nasal Obstruction Symptom Evaluation, and Berlin, related to daytime sleepiness, sleep quality, nasal obstruction, and obstructive sleep apnea syndrome (OSAS), respectively. Statistical Analysis The Kolmogorov–Smirnov test was used to assess the normality of continuous quantitative data and, posteriorly, the chi-square test was used to show if there were any associations. The significance level adopted was 5%. Results An association between daytime sleepiness and nasal obstruction was observed at the beginning of the school year (T1) (p = 0.002) and at the end of the school year (T2) (p = 0.043). In T2, an association between nasal obstruction and sleep quality was also observed (p = 0.026). The academic performance (AP) was only associated with the OSAS in T1 (p = 0.012). There was no significant difference in AP between the beginning and the end of the academic year (p = 0.935). Conclusion With the methodology used, it was observed that nasal obstruction influenced sleep quality and daytime sleepiness, and daytime sleepiness did not have any influence on AP.

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There are few reports in the literature concerning needle fractures during the local administration of anesthetic solution in dental procedures. However, the risk still exists. The patient’s unexpected movement during anesthesia, bending the needle prior to its use in the tissue, incorrectly performed anesthetic technique, uncooperative patient, small needle diameter or size may be considered substantial risks of fracture. At the moment the needle fracture occurs in the tissues it can move to the patient’s vital regions, and it is of utmost importance to remove it. If it is not possible to remove the needle immediately, an oral surgeon should be contacted to remove it under general anesthesia at the hospital. This paper aims to report a case of needle fracture in third molar exodontia during lower alveolar, lingual and buccal right nerve block, referred to the oral and maxillofacial surgery and traumatology department of the State University of Maringá. After clinical examination and tomography assessment, the patient underwent a surgical procedure to remove the needle in the operating room under general anesthesia and aid of trans-operative fluoroscopy. Therefore, we conclude that fluoroscopy is an extremely important resource in cases such as this one, since it allows a guided procedure, reducing the surgical trauma of an exploratory surgery.

Clinical and radiographic diagnosis of Nasopalatine Duct cyst treated by total enucleation -Case reportDiagnóstico clínico e radiográfico de cisto do Ducto Nasopalatino tratado por enucleação total -Relato de caso

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