Reduced Periodontal Support for Lower Central Incisor - A 3D Finite Element Analysis of Compressive Stress in the Periodontium.

BACKGROUND: The aim of this study was to assess the stress concentration in simulated periodontal alveolar bone containing healthy teeth with and without attachment loss. METHODS: Six 3-D models of a lower central incisor were created simulating the teeth structure, cancellous and cortical bone and periodontal ligament. Each model presented a 1mm increasing distance between cement-enamel junction (CEJ) and alveolar bone crest (ABC) (1 to 6mm). A 100N, 45-degree load was applied to the buccal face of the lower central incisor. The effects of Minimum Principal Stress (MPS) on lamina dura (LD) and ABC were analyzed. RESULTS: The results showed an increase of MPS in the surrounding bone (ABC and LD) due to periodontal attachment loss. The 6mm attachment loss model showed the highest (p less than 0.001) magnitude in MPS. Each millimeter increase in CEJ-ABC distance generated a 12% pattern of attachment loss and an increase at least of 65.7% for ABC and 33.6% for LD. CONCLUSION: Under simulated conditions, attachment loss increases stress concentration in the surrounding bone suggesting a partly explanation regarding bone resorption risk for teeth with periodontal attachment loss.

Experience of caries and tooth loss in rural citrus workers in Northeast Brazil / Experiência de cárie e perda dentária de trabalhadores rurais da citricultura no Nordeste brasileiro

Objective: To evaluate the experience of caries and tooth loss in rural citrus workers in Northeast Brazil. Methods: This was a cross-sectional, quantitative, and descriptive study carried out using a non-probabilistic sample of rural citrus workers linked to the Occupational Health Reference Center. Generalist and dental questionnaires were applied and clinical examinations were performed by two calibrated examiners on 619 participants in Basic Health Units to establish the sample DMFT index and to detail their characteristics of interest. Results: The sample was predominantly male (71%), with young adults between 20 and 40 years (50,9%), with low education (76%) and low income (59,3%). The mean DMFT index of the sample was 14.29 and the component regarding tooth loss (M) 9.97, corresponding to approximately 70% of this value. Moreover, 90,1% of the evaluated participants had losses of at least one dental element and 27,8% had a functional loss with less than 21 teeth in the oral cavity, while 86.3% said they had never attended an oral health service. Of the participants who have already attended, 83,6% were over six months ago, motivated by pain (43,8%) and caries (14,7%). Conclusions: The rural citrus workers evaluated had negative experiences with dental caries and a high rate of functional tooth loss, leading them vulnerable to stomatognathic system imbalances and showing the need for prevention and promotion of oral health

Objetivo: Avaliar a experiência de cárie e perda dentária de trabalhadores rurais da citricultura no Nordeste brasileiro. Métodos: Trata-se de um estudo transversal, quantitativo e descritivo, realizado com amostra não probabilística de citricultores rurais vinculados ao Centro de Referência em Saúde do Trabalhador. Foram aplicados questionários (generalista e odontológico), e exames clínicos foram realizados por dois examinadores calibrados em 619 participantes em Unidades Básicas de Saúde, para estabelecer o índice CPO-D da amostra e detalhar suas características de interesse. Resultados: A amostra foi predominantemente masculina (71%), com adultos jovens entre 20 e 40 anos (50,9%), com baixa escolaridade (76%) e baixa renda (59,3%). O índice CPO-D médio da amostra foi de 14.29, e o componente relativo à perda dentária (P) de 9.97, correspondendo a aproximadamente 70% desse valor. Além disso, 90,1% dos participantes avaliados tiveram perdas de, pelo menos, um elemento dentário, e 27,8% tiveram perda funcional com menos de 21 dentes na cavidade oral, enquanto 86,3% afirmaram nunca ter frequentado um serviço de saúde bucal. Dos participantes que já frequentaram, 83,6% foram há mais de seis meses, motivados por dores (43,8%) e cárie (14,7%). Conclusões: Os citricultores rurais avaliados apresentaram experiências negativas com cárie dentária e alto índice de perda funcional dos dentes, tornando-os vulneráveis aos desequilíbrios do sistema estomatognático e evidenciando a necessidade de prevenção e promoção da saúde bucal.

A complete physical mapping of the vitamin D receptor gene for dental implant loss: A pilot study.

OBJECTIVES: The aim of this pilot case-control study was to investigate the association of clinical variables and genetic polymorphisms in the vitamin D receptor gene (VDR) with dental implant loss. MATERIAL AND METHODS: This study was carried out with 244 individuals with mean age 51.90 ± 11.28 (81 cases and 163 controls matched by age, sex, and smoking habit). Also, the clusterization phenomenon was investigated stratifying the sample into two groups: (a) 34 patients with multiple losses (presenting two or more lost implants) and (b) 210 without multiple losses (up to one implant loss). Sociodemographic, clinical, and periodontal parameters were analyzed. The tagSNPs in the VDR gene were analyzed by real-time PCR. Univariate and multivariate analyses were performed (p < .05). RESULTS: Edentulism, number of implants installed, and Gingival, Plaque, and Calculus Indexes were associated with implant loss in the univariate analysis. After the multivariate analysis, the allele G of rs3782905 in the recessive model, together with number of installed implants and Gingival Index, was associated with implant failure. CONCLUSION: It is suggested that the allele G of rs3782905 in the recessive model may be a new genetic risk marker for dental implant loss in patients who lost two or more dental implants. In addition, number of implants installed and Gingival Index were also associated. Replication is mandatory to confirm these findings, due to the modest sample size of this work.

Adult individuals with congenital, untreated, severe isolated growth hormone deficiency have satisfactory muscular function.

PURPOSE: While growth hormone (GH) and the insulin-like growth factor type I (IGF-I) are known to exert synergistic actions on muscle anabolism, the consequences of prolonged GH deficiency (GHD) on muscle function have not been well defined. We have previously described a large cohort of subjects with isolated GHD (IGHD) caused by a mutation in the GH-releasing hormone receptor gene, with low serum levels of GH and IGF-I. The aim of this study was to assess muscular function in these IGHD subjects. METHODS: A total of 31 GH-naïve IGHD (16 males) and 40 control (20 males) subjects, matched by age and degree of daily physical activity, were enrolled. Fat free mass was measured by bioelectrical impedance; muscle strength by dynamometry of handgrip, trunk extension, and knee extension; myoelectric activity and muscle fatigue by fractal dimension; conduction velocity in vastus medialis, rectus femoris, and vastus lateralis muscles by surface electromyography. RESULTS: The IGHD group showed higher knee extension strength both when corrected for weight and fat free mass, and higher handgrip and trunk extension strength corrected by fat free mass. They also exhibit higher conduction velocity of the muscles vastus medialis, rectus femoris, and vastus lateralis, but lower free fat mass and myoelectric activity of the vastus medialis, rectus femoris and vastus lateralis. There were no differences between the two groups in fractal dimension in all studied muscles. CONCLUSION: Individuals with untreated IGHD have better muscle strength parameters adjusted for weight and fat free mass than controls. They also exhibit greater peripheral resistance to fatigue, demonstrating satisfactory muscle function.

Clinical aspects and polymorphisms in the LTA, TNFA, LTB genes and association with dental implant loss.

BACKGROUND: This study shows the relationship between host factors and environmental factors in the influence of susceptibility to loss of dental implants. PURPOSE: The aim of this study was to investigate the association of clinical aspects and tag SNPs of the genes LTA, TNFA, and LTB with dental implant loss. MATERIALS AND METHODS: The subjects consisted of 244 patients, divided into two groups: control group (C)-163 individuals who did not lose any implants, being in function for at least 6 months; and study group (S)-81 individuals who had lost at least one implant. DNA was collected from saliva, and the genotypes were determined by real time PCR. Univariate and multivariate analysis were employed p < .05. RESULTS: After multivariate analysis, dental implant loss remained associated with the presence of teeth (p = .011), a larger amount of placed implants (p = .001), and allelle C of rs2009658 of the LTA gene (p = .006). For the other tag SNPs of these studied genes, there was no association between the groups C and S with dental implants loss. CONCLUSION: Presence of teeth, number of placed implants and allele C of rs2009658 of LTA gene were associated with implant loss.

Analysis of association of clinical aspects and IL1B tagSNPs with severe preeclampsia.

OBJECTIVE: This study investigates the association between IL1B genotypes using a tag SNP (single polymorphism) approach, maternal and environmental factors in Brazilian women with severe preeclampsia. METHODS: A case-control study with a total of 456 patients (169 preeclamptic women and 287 controls) was conducted in the two reference maternity hospitals of Sergipe state, Northeast Brazil. A questionnaire was administered and DNA was extracted to genotype the population for four tag SNPs of the IL1Beta: rs 1143643, rs 1143633, rs 1143634 and rs 1143630. Haplotype association analysis and p-values were calculated using the THESIAS test. Odds ratio (OR) estimation, confidence interval (CI) and multivariate logistic regression were performed. RESULTS: High pregestational body mass index (pre-BMI), first gestation, cesarean section, more than six medical visits, low level of consciousness on admission and TC and TT genotype in rs1143630 of IL1Beta showed association with the preeclamptic group in univariate analysis. After multivariate logistic regression pre-BMI, first gestation and low level of consciousness on admission remained associated. CONCLUSION: We identified an association between clinical variables and preeclampsia. Univariate analysis suggested that inflammatory process-related genes, such as IL1B, may be involved and should be targeted in further studies. The identification of the genetic background involved in preeclampsia host response modulation is mandatory in order to understand the preeclampsia process.

Different contribution of BRINP3 gene in chronic periodontitis and peri-implantitis: a cross-sectional study.

BACKGROUND: Peri-implantitis is a chronic inflammation, resulting in loss of supporting bone around implants. Chronic periodontitis is a risk indicator for implant failure. Both diseases have a common etiology regarding inflammatory destructive response. BRINP3 gene is associated with aggressive periodontitis. However, is still unclear if chronic periodontitis and peri-implantitis have the same genetic background. The aim of this work was to investigate the association between BRINP3 genetic variation (rs1342913 and rs1935881) and expression and susceptibility to both diseases. METHODS: Periodontal and peri-implant examinations were performed in 215 subjects, divided into: healthy (without chronic periodontitis and peri-implantitis, n = 93); diseased (with chronic periodontitis and peri-implantitis, n = 52); chronic periodontitis only (n = 36), and peri-implantitis only (n = 34). A replication sample of 92 subjects who lost implants and 185 subjects successfully treated with implants were tested. DNA was extracted from buccal cells. Two genetic markers of BRINP3 (rs1342913 and rs1935881) were genotyped using TaqMan chemistry. Chi-square (p < 0.05) compared genotype and allele frequency between groups. A subset of subjects (n = 31) had gingival biopsies harvested. The BRINP3 mRNA levels were studied by CT method (2(ΔΔCT)). Mann-Whitney test correlated the levels of BRINP3 in each group (p < 0.05). RESULTS: Statistically significant association between BRINP3 rs1342913 and peri-implantitis was found in both studied groups (p = 0.04). The levels of BRINP3 mRNA were significantly higher in diseased subjects compared to healthy individuals (p = 0.01). CONCLUSION: This study provides evidence that the BRINP3 polymorphic variant rs1342913 and low level of BRINP3 expression are associated with peri-implantitis, independently from the presence of chronic periodontitis.

Lactotransferrin Gene (LTF) Polymorphisms and Dental Implant Loss: A Case-Control Association Study.

BACKGROUND: Dental implants have been widely used to replace missing teeth, accomplishing aesthetics and function. Due to its large use worldwide, the small percentage of implant loss becomes significant in number of cases. Lactotransferrin (LTF) is a pleiotropic protein, expressed in various body tissues and fluids, which modulates the host immune-inflammatory response and bone metabolism, and might be involved in dental implant osseointegration. Recently, a few studies have been investigating genetic aspects underlying dental implant failure. PURPOSE: This case-control study aimed to investigate the association of genetic markers (tag SNPs) in LTF gene and clinical parameters with dental implant loss. MATERIAL AND METHODS: 278 patients, both sexes, mean age 51 years old, divided into 184 without and 94 with implant loss, were genotyped for sixteen tag SNPs, representative of the whole LTF gene. Also, clinical oral and systemic parameters were analyzed. Univariate and Multivariate Logistic Regression model were used to analyze the results (p < .05). RESULTS: No association was found between the tag SNPs and implant loss in the study population. Clinical association was found with medical treatment, hormonal reposition, edentulism, number of placed implants, plaque, calculus, and mobility. CONCLUSION: Clinical variables, but not LTF gene polymorphisms, were associated with implant loss.

Association of interleukin 4 gene polymorphisms with dental implant loss.

PURPOSE: The purpose of this study was to investigate the association between interleukin 4 (IL4) polymorphisms/haplotypes and dental implant loss. MATERIALS AND METHODS: Two hundred and seventy eight (n = 278) unrelated patients were divided into 2 groups: (1) control group (C) composed of 186 individuals presenting at least 1 osseointegrated implant and (2) study group (S) composed of 94 individuals presenting at least 1 implant loss. After DNA collection, IL4 polymorphisms were investigated by polymerase chain reaction (PCR)-restriction fragment length polymorphism and for the variable number of tandem repeat (VNTR) only by PCR. RESULTS: No association between alleles/genotypes of -590 (C/T) (P = 0.9704/P = 0.5992) and VNTR (P = 0.7155/P = 0.8789) polymorphisms and implant loss were found between the groups. Regarding +33 (C/T) polymorphism, no difference was found in genotype frequency (P = 0.1288), but the C allele was associated with implant loss (P = 0.0236, odds ratio = 1.61, 95% confidence interval = 1.1-2.4). Haplotype analysis showed no statistical differences between the groups. CONCLUSION: The C allele of the +33 (C/T) polymorphism in the IL4 gene was associated with susceptibility to dental implant loss in Brazilians in the studied population.

The use of Twin Force functional fixed orthopedic appliance in the treatment of Class II division 1 malocclusion.

Fixed protruding appliances are interesting tools for correction of Class II dental malocclusion in adult and growing patients. The appliances most commonly used for this purpose are: Herbst, Forsus and Jasper Jumper. The present clinical case report shows an alternative called Twin Force Bite Corrector which was used for 3 months by a patient aged 10 years and 6 months associated with the Andrews prescription fixed appliance (Abzil 3M). After treatment, malocclusion was found to be adjusted to Class I dental occlusion in a single stage.

The prevalence of severe maternal morbidity and near miss and associated factors in Sergipe, Northeast Brazil.

BACKGROUND: The investigation of severe maternal morbidity (SAMM) and maternal near miss (NM) and associated risk factors is important for the global reduction of maternal mortality. This study investigated the prevalence of SAMM and NM cases and the associated risk factors in two reference maternity hospitals in a capital city in Northeast-Brazil. METHODS: A cross-sectional study with a nested case-control component was conducted from June-2011 to May-2012. Case identification was prospective and data collection was performed according to WHO criteria and definitions. Odds ratio with confidence intervals and multivariate analysis were used whenever possible. RESULTS: There were 16,243 deliveries, 1,102 SAMM cases, 77 NM cases and 17 maternal deaths. The maternal NM outcome ratio was 5.8 cases/1,000 live births (LB); the total prevalence of SAMM + NM was 72.6 cases/1,000 LB, the maternal near miss: mortality ratio was 4.5cases/1 maternal death (18% of mortality index). Management-based criteria were the most common events for NM (87.1%) and hypertensive disorders for SAMM (67.5%). Higher age, previous abortion and caesarean delivery, the non-adhesion to antenatal care, current caesarean delivery and bad perinatal results were associated with SAMM/NM. In the multivariate analysis, patient's status, previous caesarian and abortion and level of consciousness were significant when analyzed together. CONCLUSIONS: SAMM and NM situations were prevalent in the studied population and some risk factors seem to be associated with the event, particularly previous gestational antecedents. Protocols based on SAMM/NM situations can save lives and decrease maternal mortality.

Genetic association study between Interleukin 10 gene and dental implant loss.

OBJECTIVE: Three single nucleotide polymorphisms (SNPs), -1082, -819 and -592, located on the promoter region of IL10 gene have been associated with high in vitro IL-10 production and autoimmune diseases. We aim to investigate whether polymorphisms in the IL10 gene would influence dental implant loss. METHODS: We evaluated a total of 277 unrelated patients, including 185 individuals presenting at least one osseointegrated implant in function for six months or more and with no implant failure, and 92 individuals presenting at least one implant loss. DNA was extracted from buccal mucosa cells and SNPs were genotyped using TaqMan(®) probes-based assays. RESULTS: Multiple logistic regression showed association between dental implant failure with -819(C/T) genotype (OR=3.27; 95% CI=1.02-10.46; p=0.0334). However, considering the statistical significance level α=0.004 (adjusted by Bonferroni correction of multiple comparisons), these results lost their significance. No association of dental implant loss with genotypes and alleles of the -1082 and -592 SNPs, as well as IL10 haplotypes in genotype/allele forms were found (p=0.9400; p=0.8861). CONCLUSIONS: Neither the IL10 gene polymorphisms, nor haplotypes or other covariates were associated with susceptibility to dental implant failure in the studied population.

Analysis of the association of IL1B(C-511T) polymorphism with dental implant loss and the clusterization phenomenon.

OBJECTIVES: Endosteous dental implants consist in the treatment of choice to replace tooth loss. The knowledge that implant loss tends to cluster in subsets of individuals may indicate that host immune-inflammatory response is influenced by genetic factors. Interleukin-1 (IL-1) is a key mediator of inflammatory processes and functional polymorphisms in IL1 gene could be candidate genetic risk factors to study susceptibility to implant failure. The objective of this study was to investigate the association between IL1B (C-511T) genetic polymorphism and dental implant loss in a Brazilian population and its influence in the clusterization phenomenon. MATERIAL AND METHODS: The sample composed of 277 unrelated, both gender, mean age 53.63 ± 11.14 years individuals, divided into test group - 92 subjects with implant loss, and control group - 185 subjects with no implant loss. Patients' socioeconomic profile and clinical variables were investigated. Genomic DNA from oral mucosa was analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: There was significant difference between the groups in medical treatment (P=0.040), edentulism (P=0.019), and mean number of placed implants (P=0.001). There was difference between groups with and without implant loss neither considering genotypes (P=0.279) nor alleles (P=0.168) for IL1B (C-511T) polymorphism. When individuals showing up to one implant failure (n=254) were investigated vs. patients presenting multiple implant loss (n=23), no difference was either observed between groups for genotype (P=0.083) and allele (P=0.838) frequencies. CONCLUSIONS: The borderline association of the study polymorphism with implant loss suggests further IL1 haplotype analysis to elucidate the global involvement of IL-1 proteins in the modulation of the osseointegration process.

Association of IL1 gene polymorphisms with chronic periodontitis in Brazilians.

UNLABELLED: Chronic periodontal disease (PD) is an infectious immune-inflammatory illness. Polymorphisms in IL1 genes play a role in inflammatory diseases through the modulation of cytokine levels. OBJECTIVE: this study aimed to investigate the association between polymorphisms in the IL1 gene cluster and chronic periodontitis in a Brazilian population. DESIGN: a sample of 113 subjects over 25 years (mean age 41.2) were grouped into: 44 healthy individuals, 31 subjects with moderate and 38 with severe periodontitis. DNA was obtained through a mouthwash and oral mucosa scraping. PCR-RFLP was used to identify the following polymorphisms: IL1A C-889T (rs1800587), IL1B C-511T (rs16944), IL1B C+3954T (rs11436340), IL1RN intron 2 (rs2234663). Differences in the allele/genotype/haplotype frequencies were assessed by Chi-square test (p<0.05). The risk associated with alleles, genotypes and haplotypes was calculated as odds ratio (OR) with 95% confidence intervals (CI). RESULTS: neither IL1A (C-889T) nor IL1B (C+3954T) polymorphisms was associated with chronic PD. Allele T for IL1B (C-511T) only associated with PD in the group of blacks and mulattos. Moreover, genotype 2/2 for IL1RN (intron 2) was associated with severe PD. CONCLUSIONS: genotype 2/2 of IL1RN for the whole Brazilian population and allele T of IL1B (C-511T) in a subgroup of Afro-Americans and mulattos were suggested as putative risk indicators for chronic periodontitis.

Analysis of the association of IL1B (C+3954T) and IL1RN (intron 2) polymorphisms with dental implant loss in a Brazilian population.

BACKGROUND: Although dental implants have a high success rate, failures occur, in spite of adequate clinical conditions. Together with the observation that multiple implant losses occur in certain groups of individuals (clusterization phenomenon), this suggests that host response may influence implant failure. Little is known about the influence of genetic susceptibility on implant loss. Interleukin (IL)-1 beta and IL-1 ra are believed to play a key role in the immune-inflammatory response, and polymorphisms IL1B (C+3954T) and IL1RN (intron 2) are shown to alter the coding proteins expression. OBJECTIVES: The aim of this study was to investigate the association between dental implant loss and polymorphisms IL1B (+3954) and IL1RN (intron 2). MATERIAL AND METHODS: The study population (n=266) was divided into Test group (T)- 90 subjects with implant loss, and Control group (C)- 176 subjects without any implant failure. Genotyping was performed by PCR-RFLP. RESULTS: The number of present teeth was observed to influence implant loss. No differences in genotype and allele frequencies between C and T were found for IL1B (+3954) and IL1RN (intron 2) polymorphisms. However, the analysis of the whole study population (control and test groups) showed that genotype 2/2 was significantly more frequent in individuals with multiple implant losses (n=35) than in individuals that lost up to a single implant (n=231) (OR: 3.07, IC: 1.13-8.34, P=0.027). CONCLUSION: It was observed that number of teeth and edentulism were associated with implant loss. Genotype 2/2 of IL1RN polymorphism was significantly more frequent in patients who presented multiple losses, which suggests that the clusterization phenomenon has a genetic basis.

Analysis of association of clinical aspects and vitamin D receptor gene polymorphism with dental implant loss.

UNLABELLED: Osseointegration failure is a complex, multifactorial trait shown to concentrate in some treated populations. There has been shown evidence for genetic contribution to dental implant loss. Genetic polymorphisms have been classically considered as genetic risk factors for several diseases and, more recently, for dental implant loss. OBJECTIVES: The purpose of this study was to access clinical factors related to failure process, and to investigate the relationship between a vitamin D receptor (VDR) polymorphism (rs731236, TaqI) and dental implant loss. MATERIAL AND METHODS: Two hundred and seventeen unrelated patients, mean age 51.7+/-11.3 years, were divided into two groups: (i) control group (C), 137 individuals presenting at least one osseointegrated implant in function for 6 months or more and without any implant loss, and (ii) study group (S), 80 individuals presenting at least one implant loss. After DNA collection and purification, VDR TaqI polymorphism analysis was performed by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Differences between C and S, and between healthy (H; n=1232) and lost (L; n=135) implants were accessed. RESULTS: Positive evidence of association has been detected between implant loss and the following variables: edentulism, implant position, primary stability, and implant length. Cox's regression model showed that primary stability, surgical technique and bone quantity were related to implant survival over time. No association between genotypes or alleles of VDR TaqI polymorphism and implant loss was found between the groups. CONCLUSION: It was observed that clinical variables, but not the study polymorphism, were associated with dental implant loss.