Periodontal disease and oral health-related behavior as factors associated with preterm birth: a case-control study in south-eastern Brazil.

BACKGROUND AND OBJECTIVE: Several studies have suggested a link between periodontal disease and preterm birth, but the mechanism of how this occurs remains controversial. Therefore, this study aimed to investigate whether periodontal disease, defined according to two commonly used clinical definitions, is associated with preterm birth and to examine the association regarding oral health-related behaviors during pregnancy. MATERIAL AND METHODS: This case-control study included women 18-40 years of age. Demographic and socio-economic data, information on current and previous pregnancies, and data on dental health-related behaviors and periodontal clinical parameters were collected within 48 h postpartum. Periodontal disease was assessed according to two definitions: four or more teeth with at least one site showing a probing depth of ≥ 4 mm and clinical attachment level of ≥ 3 mm (Definition 1); or at least one site with probing depth and clinical attachment level of ≥ 4 mm (Definition 2). The chi-square test was used to examine differences in the proportion of categorical variables. Bivariate analysis was performed to analyze the proportion of preterm births with respect to independent variables. Multiple logistic regression analyses were used to assess the association between periodontal disease and preterm birth. Odds ratios (ORs) were calculated with a 95% confidence interval (95% CI). RESULTS: A total of 296 postpartum women met the inclusion criteria. The case group included 74 women who delivered a preterm neonate (< 37 wk of gestation) and the control group included 222 women with deliveries at term (≥ 37 wk). Periodontal disease according to Definition 1 was not associated with fewer weeks of gestation (adjusted OR (OR adjusted ) = 1.62; 95% CI = 0.80-3.29; p = 0.178). However, a significant association was found between periodontal disease, according to Definition 2, and preterm birth (OR adjusted = 1.98; 95% CI = 1.14-3.43; p = 0.015). Increased appetite and a low number of daily toothbrushings were associated with preterm birth, regardless of the definition of periodontal disease used. CONCLUSION: Periodontal disease defined according to Definition 2 and unfavorable oral health-related behavior were factors associated with preterm birth.

Influence of maxillomandibular positioning in cone beam computed tomography for implant planning.

The aim of this study was to evaluate the influence of changes in maxillomandibular positioning during cone beam computed tomography (CBCT) imaging on the planning of dental implants. Ten skulls were marked bilaterally with metal spheres in four regions: incisors, canine, premolars, and molars. CBCT scans were obtained in seven positions: standard position (SP), displacements of 10° and 20° above and below the SP, and lateral displacements of 10° and 20° from the SP. Subsequently, bilateral measurements of the height and width of the maxilla and mandible were performed on all images. The results showed that the position with a displacement of 20° above the SP presented the greatest differences in the measurements of bone height and width. In the bilateral comparisons, the maxillary bone width showed the greatest differences, especially for the regions of the premolars and molars. It is concluded that alterations of positioning during the acquisition of CBCT images can lead to alterations in the measurements of bone height and width, which may result in errors in implant planning and cause damage to anatomical structures.

Expression of IL-1ß, IL-6, TNF-α, and iNOS in pregnant women with periodontal disease.

Periodontal disease is one of the most prevalent oral diseases. An association between this disease and pregnancy has been suggested, but available findings are controversial. We evaluated the expression levels of interleukins (IL-1ß and IL-6), tumor necrosis factor-alpha (TNF-α), and inducible nitric oxide synthase (iNOS) in pregnant women with and without periodontal disease in comparison with non-pregnant women with and without periodontal disease since studies have suggested a relationship between periodontitis and the expression levels of these genes. The women in the sample were distributed into four groups: pregnant and non-pregnant women, with or without periodontal disease, a total of 32 women. The periodontal condition was evaluated according to the probing depth, clinical attachment level and bleeding on probing. Analysis of gene expression was performed by real-time PCR. Comparisons were made of the level of gene expression among the four groups. Expression of IL-1ß in the non-pregnant women with periodontal disease was 12.6 times higher than in the non-pregnant women without periodontal disease (P < 0.01), while expression of TNF-α in the non-pregnant women without periodontal disease was 3.5 times higher than in the pregnant women with periodontal disease (P < 0.05). Despite these differences, our overall findings indicate no differences in the expression levels of the cytokines IL-1ß, IL-6, TNF-α, and iNOS in pregnant women with and without periodontal disease in comparison with expression of the same genes in non-pregnant women with and without periodontal disease, suggesting that periodontal disease is not influenced by pregnancy.