Abstract Aim: Polymorphisms in the COMT gene can alter enzymatic functions, raising levels of endogenous catecholamines, which stimulates beta-adrenergic receptors related to pain. This study aimed to evaluate whether a polymorphism in the COMT gene (rs4818) is associated with dental pain in children. Methodology: A cross-sectional study was conducted with a representative sample of 731 pairs of children and parents randomly selected from a population-based sample of eight-year-old children. Reports of dental pain was evaluated using a question directed at the parents and self-reported pain using the Faces Pain Scale – Revised. Dental caries experience was determined using the Decayed, Missing, and Filled Teeth (DMFT) index. For genetic analysis, DNA was obtained from oral mucosa epithelial cells of 352 children randomly selected from the initial sample. Results: Children with the CC genotype had higher odds of reporting moderate to intense pain than those with the GG genotype (OR=3.60; 95% CI=0.80–16.20; p=0.03). These same children had greater odds of parental reports of pain (OR=1.93; 95% CI=0.91-4.08; p=0.02). Moreover, lower schooling of parents/guardians and caries experience in the primary dentition were significantly associated with greater odds of a parental report of dental pain (OR=2.06; 95% CI=1.47–2.91; p<0.001; OR=6.26; 95% CI=4.46–8.78; p<0.001). Conclusions: The rs4818 polymorphism of the COMT gene is associated with dental pain. Children with the C allele are more likely to report higher levels of pain. Clinical Relevance: Even though the experience of pain is subjective and multifactorial, this study raises the hypothesis that there is a genetic predisposition to dental pain that should be considered in clinical practice.

ABSTRACT Objective: To investigate the association between single nucleotide polymorphisms in the COX2 gene (rs689466 and rs5275) and local and systemic signs and symptoms of teething. Material and Methods: Forty-four pairs of mothers-babies/toddlers were included. Erupted primary teeth were evaluated during clinical examination. Local and systemic signs and symptoms of teething were obtained from mothers' reporting via anamnesis. Samples of buccal cells were retrieved for DNA genotyping using real-time PCR. The T-test, Chi-square test, logistic regression, and haplotype analyses were applied. Results: Almost all mothers (95.5%) reported at least one local or systemic sign and symptom of teething. The most common was increased salivation (79.5%), diarrhea (72.3 %), and fever (70.5 %). The mean number of signs and symptoms per child was higher in boys than girls (mean = 5.1; SD= 1.5; p=0.008). Sleep disturbance (p=0.03) and loss of appetite (p=0.05) were more reported in boys. The rs689466 and rs5275 were not associated with signs and symptoms of teething (p>0.05). Conclusion: The single nucleotide polymorphisms in the COX2 gene (rs689466 and rs5275) were not associated with local and systemic signs and symptoms of teething.

RESUMO O objetivo do presente estudo foi investigar a associação entre polimorfismos de nucleotídeo único (SNPs) em genes que codificam receptores de estrógeno (ESR1 e ESR2, respectivamente) e o retardo na emergência dentária (DTE). Este estudo transversal foi composto por crianças biológicas não relacionadas de ambos os sexos, com idades entre 11 e 13 anos. O DTE foi definido pela presença do dente decíduo na cavidade bucal após seu tempo e também, quando as crianças apresentaram pelo menos um dente permanente com atraso. O DNA genômico foi usado para avaliar os SNPs em ESR1 (rs9340799 e rs2234693) e ESR2 (rs1256049 e rs4986938) usando PCR em tempo real. Foram realizados testes Qui-quadrado ou exato de Fisher e Regressão Logística ajustados por idade e sexo. A interação SNP-SNP foi acessada pela análise de redução de dimensionalidade multifatorial (MDR), também ajustada por sexo e idade. O alfa de 5% foi estabelecido. Entre 537 crianças incluídas, 296 (55%) estavam no grupo “DTE” e 241 (45%) estavam no grupo “Controle”. A idade e o sexo não foram estatisticamente diferentes entre os grupos (p> 0,05). A distribuição de genótipos dos SNPs rs9340799, rs2234693, rs1256049 e rs4986938 não foi associada ao DTE (p> 0,05). Os modelos eleitos pelo MDR também não foram estatisticamente significativos. Conclusões: Os SNPs estudados na ESR1 e ESR2 não foram associados ao DTE na dentição permanente.

Abstract The purpose of the study was to investigate the association between single nucleotide polymorphisms (SNPs) in genes encoding estrogen receptors (ESR1 and ESR2, respectively) and delayed tooth emergence (DTE). This cross-sectional study was composed of biological unrelated children of both sexes, age ranging from 11 to 13 years old. DTE was defined when the successor primary tooth was still present in the oral cavity after its exfoliation time or the absence of the permanent tooth emergence into the oral cavity. Children were diagnosed with DTE when they had at least one delayed permanent tooth, according to age of exfoliation of each tooth proposed by The American Dental Association. Genomic DNA from saliva was used to evaluate the SNPs in ESR1 (rs9340799 and rs2234693) and ESR2 (rs1256049 and rs4986938) using Real-Time PCR. Chi-square or Fisher exact tests and Logistic Regression adjusted by age and gender were performed. SNP-SNP interaction was accessed by multifactor dimensionality reduction (MDR) analysis also adjusted by gender and age. The established alpha of this study was 5%. Among 537 included children, 296 (55%) were in the “DTE” group and the 241 (45%) were in the “Control” group. Age and gender were not statistically different among the groups (p>0.05). Genotype distribution of the SNPs rs9340799, rs2234693, rs1256049 and rs4986938 were not associated with DTE (p> 0.05). The models elected by MDR were not statistically significant either. Conclusions: The studied SNPs in ESR1 and ESR2 were not associated with permanent DTE.

Abstract The objective of this study was to evaluate if individuals with dentofacial deformities (DFD) who require orthognathic surgery are affected more by depression and pain. A case-control study was performed with 195 individuals. In the DFD group, 145 individuals with Class II and III malocclusion requiring orthognathic surgery were selected. The control group was composed of 50 individuals with no DFD. All patients were diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Data were analyzed with a significance level of 0.05. The DFD group more often presented severe depression (p = 0.020) and chronic pain (p = 0.017). They also presented higher prevalence of Nonspecific Physical Symptoms Including Pain (P = 0.002) and Nonspecific Physical Symptoms Excluding Pain (p = 0.002). Concerning TMD symptoms, the DFD group had more myofascial (p = 0.002) and articular pain (p = 0.041). Therefore, the results of this study suggest that depression and pain are more common in individuals with DFD requiring orthognathic surgery compared with individuals without DFD.

Resumo A homeostasia entre cálcio e fósforo salivares é importante para a manutenção da saúde bucal. O objetivo deste estudo foi avaliar se polimorfismos genéticos no receptor de estrógeno alfa (ESR1), receptor de estrógeno beta (ESR2) e no microRNA17 (microRNA17) estão associados com os níveis salivares de cálcio e fósforo. Saliva de 276 crianças com 12 anos de idade foi coletada com estímulo mastigatório e os níveis de cálcio e fósforo foram determinados por Espectrofotometria de Massa. O DNA genômico foi extraído da saliva remanescente e os polimorfismos genéticos em ESR1 (rs12154178, rs1884051, rs9340799 e rs2234693), em ESR2 (rs4986938 e rs1256049) e no miRNA17 (rs4284505) foram genotipados pela reação em cadeia da polimerase em tempo real utilizando sondas TaqMan. As diferenças estatísticas nas distribuições alélicas e genotípicas entre “baixo” e “alto” níveis de cálcio e fósforo foram determinadas usando os testes qui-quadrado e teste exato de Fisher. As análises foram ajustadas por sexo (alfa de 5%). O polimorfismo rs9340799 em ESR1 foi o genótipo menos comum associado com altos níveis de cálcio (p=0,03). O alelo menos comum em ESR1 rs1884051 foi associado com baixos níveis de fósforo (p=0,005) e houve um excesso de heterozigotos para miRNA17 rs4284505 entre os indivíduos com baixos níveis de cálcio salivar (p=0,002), ambos ajustados pelo sexo. Este estudo fornece evidências de que polimorfismos genéticos em ESR1 e miRNA17 estão envolvidos na determinação dos níveis de cálcio e fósforo salivares.

Abstract Homeostasis between salivary calcium and phosphorus is important for maintaining oral health. The aim of this study was to evaluate if polymorphisms in ESR1 (Estrogen Receptor Alpha), ESR2 (Estrogen Receptor Beta) and miRNA17 (microRNA17) are associated with calcium and phosphorus levels in saliva. Saliva from 276 12-year-old children were collected by masticatory stimulation and calcium and phosphorus levels were determined by Mass Spectrometry. Genomic DNA was extracted from remaining saliva and genetic polymorphisms in ESR1 (rs12154178, rs1884051, rs9340799 and rs2234693), in ESR2 (rs4986938 and rs1256049) and in miRNA17 (rs4284505) were genotyped using TaqMan chemistry and a real-time PCR equipment. Statistical differences in genotype and allele distributions between ‘low’ and ‘high’ calcium and phosphorus levels were determined using chi-square or Fisher´s exact tests. The analysis was also adjusted by sex (alpha of 5%). ESR1 rs9340799 had the less common genotype associated with higher calcium levels (p=0.03). The less common allele of ESR1 rs1884051 was associated with lower phosphorus levels (p=0.005) and there was an excess of heterozygotes for miRNA17 rs4284505 among individuals with lower calcium levels (p=0.002), both adjusted by sex. This study provides evidence that genetic polymorphisms in ESR1 and miRNA17 are involved in determining salivary calcium and phosphorus levels.

Abstract This study was performed to evaluate the interplay between dental caries, nutritional status, and genetic polymorphisms in TAS1R1 and TAS1R2 (taste receptor, type 1, member 1 and 2) in preschool children and pre-adolescents. We included 525 subjects (306 preschool children and 219 pre-adolescents). Parents/caregivers answered a self-administered questionnaire about their children’s systemic health, characteristics, oral hygiene habits, and diet. Clinical examination was performed to evaluate dental caries and nutritional status. Saliva samples were collected for DNA extraction. The genotyping of rs17492553 ( TAS1R1 ), rs3935570, and rs4920566 ( TAS1R2 ) polymorphisms was performed using real-time PCR with Taqman Genotyping Master Mix and SNP assay. Both univariate and multivariate Poisson regression analyses with robust variance were used for the data analysis. In preschool children, consumption of sweets between meals increased the prevalence of dental caries by 85% (PR c = 1.85; 95%CI 1.39–2.46; p < 0.001), whereas in pre-adolescents, this prevalence increased by 34% (PR a = 1.34; 95%CI 1.11–1.62; p = 0.002), regardless of genetic polymorphisms . Moreover, individuals carrying at least one allele C in rs17492553 presented 23% more prevalence of dental caries (PR a = 1.23; 95%CI 1.02–1.49 p = 0.030). Nutritional status was not associated with dental caries, neither with genetic polymorphisms . Consumption of sweets between meals increased the prevalence of dental caries. In pre-adolescents, rs17492553 genetic polymorphism in TAS1R1 was associated with dental caries.

OBJECTIVE: To evaluate qualitative and quantitative changes in the saliva of individuals undergoing orthodontic treatment with fixed appliances. METHODS: Salivary samples were collected from 50 individuals divided in two groups: Experimental Group - patients with fixed orthodontic appliances (n=25); and Control Group - subjects with no orthodontic appliances (n=25). Salivary flow rate, pH, buffering capacity, amylase activity, concentrations of total proteins, calcium and glucose were measured in all salivary samples. RESULTS: There was a reduction in salivary pH and buffering capacity and an increase in the concentration of calcium ions in the experimental group (p<0.05); there was also an increase in glucose, amylase and protein concentrations in the saliva of the Experimental Group, but the differences were insignificant. There was insignificant correlation between calcium ion concentration and salivary flow or between buffering capacity and salivary flow. CONCLUSION: The saliva of individuals with fixed orthodontic appliances had lower pH, buffering capacity and calcium concentration than that of individuals without any type of orthodontic appliance. These oral changes are enough to cause tooth demineralization. Patients with orthodontic appliances should adopt additional oral hygiene procedures.

OBJECTIVE: The present study evaluated the association between lactotransferrin (LTF) gene polymorphism (exon 2, A/G, Lys/Arg) and dental caries. MATERIAL AND METHODS: A convenience sample of 110 individuals, 12 years old, was divided into: group 1, 48 individuals without caries experience (DMFT=0), and group 2, 62 subjects with caries experience (DMFT>1). DNA was obtained from a mouthwash with 3% glucose solution, followed by a scrapping of the oral mucosa. After DNA purification, polymerase chain reaction (PCR), single strand conformation polymorphism (SSCP) was performed to access the study polymorphism. The LTF A/G (Lys/Arg) polymorphism had been previously reported as located in exon 1. RESULTS: Allele 1 of the study polymorphism was associated with low DMFT index and showed a protective effect against caries experience (OR=0.16, IC=0.03-0.76, p=0.01). CONCLUSIONS: Lactotransferrin A/G (exon 2, Lys/Arg) polymorphism was associated with susceptibility to dental caries in 12-year-old students.