Hyoid bone position and vertical skeletal pattern--open bite/deep bite

The Hyoid Bone (HB) is a singular bone with no articulation, but is associated with some vital functions. The purpose of this study was to test the null hypotheses that there is no change in HB position in individuals with vertical jaw dysplasia.

METHODS

Eleven factors were used to determine the position of the HB. In this paper the ANOVA (two way analysis of variance) method was used to analyze the variability of the mean of each HB position according the factors facial type and gender. Comparisons with these procedures define which measurements were associated with facial type, gender; and the interactive associations between them.

RESULTS

The HB is related with vertical facial skeletal pattern being farther from mandible and a line joining it to the third cervical vertebra in deep bite, and from posterior nasal spine and sella turcica in open bite. There is sexual dimorphism in HB position. Men have a significant lower distance to the mandible and to the vertical pterigoidea; and higher values to the third cervical vertebra, to a line joining this vertebra to mandible, to the posterior nasal spine and to the sella turcica. Also, there is an association between HB position related group and gender.

CONCLUSION

In this research there is a relation between the position of HB and vertical skeletal pattern. The position of the HB is more related with deep bite. There is a possibility of including the HB in the differential diagnosis of this dysplasia.

Oral habits as risk factors for anterior open bite in the deciduous and mixed dentition - cross-sectional study

AIM

Anterior open bite (AOB) is an occlusal anomaly commonly associated with oral habits (OH). The aim of this study was to determine the prevalence of OH as a risk factor for the AOB.

MATERIALS AND METHODS

A group of children aged between 3 and 12 years were observed. The statistical methodology included independent chi-square test, Fisher's exact test and binary logistic regression.

RESULTS

The frequency of oral habits was of 43.5% in the deciduous dentition and 54.2% in the mixed dentition. There was a statistically significant association of pacifier sucking: 61.7 and 16.1 odd ratios (OR), and tongue thrust: 3.9 and 9.2 OR with AOB in both groups, respectively. Thumb sucking occurred only in the deciduous dentition with 5.6 OR.

CONCLUSION

OH and AOB have a high frequency in children. They hinder the normal development of dental and skeletal structures. As OH are risk factors for AOB, the damaging habits most frequently associated are: pacifier sucking, thumb sucking, and tongue thrust. Due to the correlation between the prevalence of AOB and OH, prevention strategies incorporating psychological data related to children should be integrated into a national public health programme.

IL1 gene polymorphisms and unsuccessful dental implants

OBJECTIVES

This study aimed to analyse the association between polymorphisms in the IL1 gene cluster and failure of dental implants in a Portuguese population.

MATERIAL AND METHODS

A total of 155 Caucasian Portuguese subjects were divided into two groups: 100 with successful dental implants and 55 with unsuccessful dental implants. DNA was obtained through an oral mucosa scraping. PCR was used to identify the polymorphisms: single nucleotide changes in positions -889 of IL1A gene and +3953 of IL1B gene.

RESULTS

The prevalence of the polymorphisms -889IL1A gene and +3953IL1B gene, determined by the positive result of TGP (Genetic Test for Periodontitis; CGC, Genetics, Portugal), in the studied population rehabilitated with dental implants was of 33.50%. Allele 1 of the IL1B gene was the most prevalent (62.20%), followed by allele 1 of the IL1A gene (54.80%) and the least frequent was allele 2 of IL1B gene (37.40%). Success of dental implants was mainly associated with a negative TGP result, whereas no success was found to be related to a positive result. There were no statistically significant differences between the alleles 1 and 2 of the genes IL1A and IL1B and the tobacco and alcohol consumption for the success or no success of the dental implants.

CONCLUSIONS

The alleles 1 and 2 of IL1A gene and the alleles 1 and 2 of IL1B gene were statistically associated with the success or no success of the dental implants. Tobacco habit and alcohol consumption showed no statistically significant association with success or no success of the dental implants.

Temporal variation in pollen dispersal and breeding structure in a bee-pollinated Neotropical tree

Variation among flowering seasons in the time of flowering, synchrony and length of flowering, and fluctuations in the abundance of pollinators may cause a variation in pollen dispersal distance. In this study, we analyzed the temporal variation in pollen dispersal and breeding structure in the Neotropical tree species Tabebuia aurea (Bignoniaceae) and evaluated pollen dispersal between a population inside the reserve and a patch of isolated individuals on the edge of the reserve, and tested the hypothesis that isolated individuals are sinking for pollen. All adult trees (260) within a population of 40 ha and 9 isolated individuals on the edge of the reserve were sampled, and from these adults, 21 open-pollinated progeny arrays were analyzed in 2 flowering seasons (309 seeds in 2004 and 328 in 2005). Genetic analyses were based on the polymorphism at 10 microsatellite loci. A high proportion of self-pollination found in both flowering seasons indicated a mixed-mating system. The mean pollen dispersal distance differed significantly between the two flowering seasons (307.78 m in 2004 and 396.26 m in 2005). Maximum pollen dispersal was 2608 m, but most pollination events (65%) occurred at distances <300 m. Our results also showed that isolated individuals are sinking for pollen, with high pollen flow between the population inside the reserve and individuals on the edge. These results are most likely due to the large pollinator species, which can potentially fly long distances, and also due to temporal variation in individual fecundity and contribution to pollen dispersal.

Assessment of the relationship between the upper and lower arch changes with the opening of the expanding screw after the rapid maxillary expansion

OBJECTIVE

The purpose of this study is to assess the relationship of the upper and lower arch dimension changes after the rapid maxillary expansion (RME) with the screw opening of the modified Hyrax® type appliance.

MATERIALS AND METHODS

Initial (T1) and final (T2) models of study of 63 children between 7 years and 6 months and 16 years and 5 months were performed. From these, 21 showed maxillary atresia and/ or posterior crossbite and were submitted to expansion and 42 children formed the control group .The appliance used in this work was the modified Hyrax appliance using the 7mm expanding screws "Dentarum". The measures of the upper intercanine and the upper and lower intermolar distances were performed in plaster models with the help of a digital paquimeter. The opening of the appliance's screw was also assessed.

RESULTS

The RME provoked a statistically significant increase in the upper interdental distances and no statistic significance in the lower interdental distances, i.e. the change in the 16 - 26, 13 - 23 and 36 - 46 distance was of 5,85 mm, 5,31 and 0,34 mm respectively. The average opening of the expander screw, which was of 6,27 mm.

CONCLUSION

The appliance's opening is related to the interdental distance changes, i.e. for each appliance's opening mm, a 0,94 variation in the upper intermolar distance, a 0,87 in the upper intercanine distance and 0,054 in the lower intermolar distance are provoked.

Fishes of the family Ipnopidae (Teleostei: Aulopiformes) collected on the Brazilian continental slope between 11 degrees and 23 degrees S

A collection of fishes from the Brazilian continental slope between 11 degrees and 23 degrees S obtained through trawling revealed nine species of Ipnopidae. Bathypterois bigelowi and Bathytyphlops marionae represent first records from the south-western Atlantic Ocean and Bathypterois grallator is reported off Brazil for the first time. Four species have their distribution extended in Brazilian waters: Bathypterois phenax, Bathypterois quadrifilis, Bathypterois viridensis and Ipnops murrayi. An identification key of Ipnopidae species from the south-western Atlantic Ocean is included.

Assessment of the effect of Maytenus ilicifolia (espinheira santa) extract on the labeling of red blood cells and plasma proteins with technetium-99m

We are trying to develop a model to assess properties of products utilized in popular medicine. Maytenus ilicifolia is used in herbal medicine. Red blood cells (RBC) labeled with technetium-99m (99mTc) are employed in nuclear medicine. This labeling procedure depends on a reducing agent and stannous chloride is used. There is evidence that this labeling may be altered by drugs. We have investigated the possibility of M. ilicifolia extract being capable to alter the labeling of blood elements with 99mTc. Blood was incubated with M. ilicifolia extract. Stannous chloride solution and Tc-99m were added. Blood was centrifuged and plasma (P) and blood cells (C) were isolated. Samples of P or C were also precipitated, centrifuged and insoluble (IF) and soluble (SF) were separated. The percentages of radioactivity (%ATI) in C, IF-P and IF-C was calculated. The %ATI decreased on C from 93.6+/-2.3 to 29.0+/-2.7, on IF-P from 77.6+/-1.2 to 7.5+/-1.0 and on IF-C from 80.0+/-3.4 to 12.6+/-4.8. Once in RBC labeling procedure with 99mTc depends on the presence of stannous (+2) ions, the substances of the M. ilicifolia extract could increase the valence these ions to stannic (+4). This fact would decrease the %ATI on blood elements and indicate the presence of oxidant agents in the M. ilicifolia extract.

The effect of drugs on the labeling of blood elements with technetium-99m

The influence of drugs on the labeling of red blood cells and plasma proteins with 99mTc has been reported. Any drug, which alters the labeling of the tracer, could be expected to modify the disposition of the radiopharmaceuticals. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. We have evaluated the effect of Thuya occidentalis, Peumus boldus and Nicotiana tabacum (tobacco) extracts on the labeling of RBC and plasma and cellular proteins with 99mTc. Blood was incubated with the drugs. Stannous chloride (SnCl2) solutions and 99mTc were added. Plasma (P) and blood cells (BC) were separated. The percentage of radioactivity (%ATI) bound to P and BC was determined. The %ATI on the plasma and cellular proteins was also evaluated by precipitation of P and BC samples with trichloroacetic acid (TCA) and isolation of soluble (SF) and insoluble (IF) fractions. The analysis of the results shows that there is a decrease in %ATI (from 97.64 to 75.89 percent) in BC with Thuya occidentalis extract. The labeling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due either a direct or indirect effect (reactive oxygen species) of tobacco. The analysis of radioactivity in samples of P and BC isolated from samples of whole blood treated with Peumus boldus showed a rapid uptake of the radioactivity by blood cells in the presence of the Peumus boldus, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique.

Sialuria in a Portuguese girl: clinical, biochemical, and molecular characteristics

Sialuria, a disorder of sialic acid (NeuAc) metabolism characterized by increased free NeuAc in the cytoplasm of cells, is due to failure of CMP-Neu5Ac to feedback inhibit UDP-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase. We now describe the fifth patient in the world with sialuria, a 7-year-old Portuguese girl with developmental delay, hepatomegaly, coarse facies, and urinary excretion of 19 micromol of free NeuAc/mg creatinine. The patient's fibroblasts stored excess free NeuAc in the cytosolic fraction, and fibroblast UDP-GlcNAc 2-epimerase activity was only 26% inhibited by 100 microM CMP-Neu5Ac (normal, 79%). The patient's UDP-GlcNAc 2-epimerase gene displayed an R266Q mutation in only one allele, consistent with known sialuria mutations and with the proposed dominant nature of this disorder. Extensive description of sialuria patients will help to define the clinical and biochemical spectrum of this disease.

Effect of Thuya occidentalis on the labeling of red blood cells and plasma proteins with technetium-99m

Thuya occidentalis is used in popular medicine in the treatment of condyloma and has antibacterial action. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. This labeling depends on a reducing agent, usually stannous ion. Any drug which alters the labeling of the tracer could be expected to modify the disposition of the radiopharmaceutical. We have evaluated the influence of T. occidentalis extract on the labeling of RBC and plasma proteins with 99mTc. Blood was withdrawn and incubated with T. occidentalis (0.25; 2.5; 20.5; and 34.1 percent v/v). Stannous chloride (1.2 micrograms/ml) was added and then 99mTc was added. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) separated. The analysis of the results shows that there is a decrease in radioactivity (from 97.64 to 75.89 percent) in BC with 34.1 percent of the drug. In the labeling process of RBC with 99mTc, the stannous and pertechnetate ions pass through the membrane, so we suggest that the T. occidentalis effect can be explained (i) by an inhibition of the transport of these ions, (ii) by damage in membrane, (iii) by competition with the cited ions for the same binding sites, or (iv) by possible generation of reactive oxygen species that could oxidize the stannous ion.