New software for cervical vertebral geometry assessment and its relationship to skeletal maturation--a pilot study.

OBJECTIVES: In the present study, we developed new software for quantitative analysis of cervical vertebrae maturation, and we evaluated its applicability through a multinomial logistic regression model (MLRM). METHODS: Digitized images of the bodies of the second (C2), third (C3) and fourth (C4) cervical vertebrae were analysed in cephalometric radiographs of 236 subjects (116 boys and 120 girls) by using a software developed for digitized vertebrae analysis. The sample was initially distributed into 11 categories according to the Fishman's skeletal maturity indicators and were then grouped into four stages for quantitative cervical maturational changes (QCMC) analysis (QCMC I, II, III and IV). Seven variables of interest were measured and analysed to identify morphologic alterations of the vertebral bodies in each QCMC category. RESULTS: Statistically significant differences (p < 0.05) were observed among all QCMC categories for the variables analysed. The MLRM used to calculate the probability that an individual belonged to each of the four cervical vertebrae maturation categories was constructed by taking into account gender, chronological age and four variables determined by digitized vertebrae analysis (Ang_C3, MP_C3, MP_C4 and SP_C4). The MLRM presented a predictability of 81.4%. The weighted κ test showed almost perfect agreement (κ = 0.832) between the categories defined initially by the method of Fishman and those allocated by the MLRM. CONCLUSIONS: Significant alterations in the morphologies of the C2, C3 and C4 vertebral bodies that were analysed through the digitized vertebrae analysis software occur during the different stages of skeletal maturation. The model that combines the four parameters measured on the vertebral bodies, the age and the gender showed an excellent prediction.

Hyptis pectinata essential oil: chemical composition and anti-Streptococcus mutans activity.

OBJECTIVES: The aim of the present study was to evaluate the anti-Streptococcus mutans activity of Hyptis pectinata essential oil, and present its promising potential against oral diseases. MATERIALS AND METHODS: The essential oil of H. pectinata was obtained by hydrodistillation from dried leaves and analyzed by GC / MS. The effectiveness of this essential oil regarding the antimicrobial activity against several S. mutans strains was investigated by the agar diffusion and microdilution methods, and chlorohexidine was used as a standard control. RESULTS: The H. pectinata essential oil exhibited considerable inhibitory effect against either all the clinical isolates obtained from patients' saliva or the ATCC strains tested, with minimum inhibitory and bactericidal concentrations of 200 microg ml(-1). The study also compared the efficiency of the emulsifying agents Tween 20, Tween 80, dimethyl sulfoxide and propylene glycol in H. pectinata essential oil when tested against S. mutans. The data obtained confirmed the better inhibitory effect of the oil when using all tested diluents, although Tween 80 seemed to be more suitable for emulsification. CONCLUSION: According to our results, H. pectinata essential oil can be considered a promising alternative to chlorhexidine for the control of oral bacteria-related diseases and hygiene.

Antimicrobial activity of Croton cajucara Benth linalool-rich essential oil on artificial biofilms and planktonic microorganisms.

We have previously demonstrated that a linalool-rich essential oil from Croton cajucara Benth presents leishmanicidal activity. In the present study, we demonstrate that this essential oil inhibits the growth of reference samples of Candida albicans, Lactobacillus casei, Staphylococcus aureus, Streptococcus sobrinus, Porphyromonas gingivalis and Streptococcus mutans cell suspensions, all of them associated with oral cavity disease. The purified linalool fraction was only inhibitory for C. albicans. Microbes of saliva specimens from human individuals with fixed orthodontic appliances, as well as the reference strains, were used to construct an artificial biofilm which was exposed to linalool or to the essential oil. As in microbial suspensions, the essential oil was toxic for all the microorganisms, while the purified linalool fraction mainly inhibited the growth of C. albicans. The compounds of the essential oil were separated by thin layer chromatography and exposed to the above-cited microorganisms. In this analysis, the proliferation of the bacterial cells was inhibited by still uncharacterized molecules, and linalool was confirmed as the antifungal component of the essential oil. The effects of linalool on the cell biology of C. albicans were evaluated by electron microscopy, which showed that linalool induced a reduction in cell size and abnormal germination. Neither the crude essential oil nor the purified linalool fraction is toxic to mammalian cells, which suggests that the essential oil or its purified components may be useful to control the microbial population in patients with fixed orthodontic appliances.

Epithelial alterations of secondary palate formation.

This study was undertaken to examine the normal and abnormal epithelial alterations of secondary palate in rats. Control and dexamethasone-treated embryos and fetuses of Wistar rats were evaluated by macroscopic and scanning electron microscopic analysis prior to, during, and after fusion of palatal processes. Normal alterations of the surface topography included growth and disorganization of medial edge epithelial cells followed by fusion and posterior migration to both the oral and nasal aspects of the palate. No evidence of epithelial cell death or transformation was observed. Dexamethasone-treated fetuses showed epithelial cells increased in size with a large amount of desquamation, followed by deposition of a disorganized cell layer with keratin-like characteristics. This allowed no fusion of palatal processes.

Bone morphology of the temporomandibular joint and its relation to dental occlusion.

The mandibular and temporal osseous components were analyzed in a sample of 30 dry skulls and their morphology was correlated with occlusal characteristics. In skulls with condyles of a more rounded shape, the depth of the fossa was greater. Furthermore, there was a significant correlation between greater depth of the fossa and skulls with normal overbite. However, no correlation was observed between depth of the fossa, tooth attrition and Spee curve.

Radiographic morphology of the temporomandibular joint related to occlusal characteristics.

The radiographic image of the temporomandibular joints of 52 individuals obtained by oblique lateral transcranial exposure was studied in terms of the appearance of the articular components (depth of the mandibular fossa, inclination of the posterior slope of the articular eminence, and condyle shape) and correlated with occlusal characteristics (overbite, tooth wear or attrition, and Spee curve). This investigation did not permit us to demonstrate a definite correlation between dental occlusion and articular morphology based on the radiographic image of the temporomandibular joint.