Bacterial composition of subgingival plaque in crowded and noncrowded teeth.

INTRODUCTION: Patients with dental crowding, even with good oral hygiene, may show increased bacterial presence in the crowded area. This study aimed to determine the microbial composition of subgingival plaque in crowded and noncrowded dental regions. METHODS: Forty dental students with anterior dental crowding, who were aware of correct brushing techniques and oral hygiene, were enrolled in this study. After orthodontic records were taken and the periodontal examination was performed, subgingival plaque samples were collected from the crowded (experimental) and noncrowded regions (control) of each patient. Colony counting was performed for Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and streptococcus species. RESULTS: The mean amount of Aa and Pg colonies was significantly higher in crowded areas (P <0.0001), but there was no significant difference between streptococcus species colonization and crowding. Aa and Pg colonization had a significant direct relation with the amount of crowding. (P <0.0001). CONCLUSIONS: Crowded dental areas, even with good oral hygiene, are more suitable environments for Aa and Pg colonization.

Incidence and Survival in Breast Cancer Patients and Stressful Life Events.

Due to increasing incidence of breast cancer, recognition of risk factors has become increasingly important. Over the past few decades, among risk factors of this disease, stressful life events have attracted particular attention, but their relationship with breast cancer incidence and survival remains a mystery. This study aimed to examine the relationship between severe stressful life events and incidence and survival of women with breast cancer. In this case-control study, using a structured telephone interview with 355 women with breast cancer and also with 516 women with benign breast diseases who were matched in demographic characteristics, necessary information about the experience of major stressful events in the years before the diagnosis were collected. Data were analyzed using statistical methods of χ2, t, and Kaplan-Meier with a significance level of <0.05. Generally, in the case and control groups, there were no significant association between experience of stressful life events and incidence of breast cancer. Regarding associations between each of the events and incidence of breast cancer only "severe interpersonal problems with spouse" was significant. In the breast cancer group, even after controlling confounding variables, there was no significant association between major stressful events and disease-free survival, or overall 5-and 10-year survival. In this study, only "severe interpersonal problems with spouse" was confirmed as a risk factor. This result can be useful in developing preventive policies. More research regarding the interactive effects of psycho-social factors in the incidence and survival of breast cancer with stressful life events is recommended.