Prevalence of Oral Microbial Flora during Orthodontic Space Closure: A Pilot Study

Abstract

Introduction: Orthodontic treatment with fixed appliances especially during the retraction stage makes it challenging to maintain the oral hygiene. Attachments used, such as elastic chains, loops and springs, result in changes in the oral environment due to the accumulation of plaque and increase in the levels of bacterial count mainly Streptococcus mutans and Lactobacilli species. Aim: To determine the prevalence of oral microbial flora during orthodontic space closure. Materials and Methods: This was a cross-sectional pilot study conducted during the month of December 2019 which consisted of eight patients who were randomly selected among the age group of 18-25 years. Mean and SD of age in Males (4) and Females (4) were 22±2.16 years and 22.25±1.70 years, respectively and had reported to the Department of Orthodontics of a private dental college, Saveetha Dental College. In each patient, after 6-8 months of orthodontic treatment, plaque samples were collected only once around the orthodontic brackets at the cervical aspect of the maxillary lateral incisor, maxillary premolar, mandibular canine, mandibular premolar in 1st, 2nd, 3rd, and 4th quadrant respectively, by the method of cotton swabbing for the evaluation of micro flora. Independent paired t-test and One-way ANOVA with Post-hoc Tukey HSD test were done to estimate the prevalence of microorganisms at different sites. Results: Independent paired t-test showed highly significant differences in the levels of Streptococcus mutans when compared to Lactobacillus (p<0.001) with mean values of 4.8±2.5 and 23.1±9.2 for Streptococcus and Lactobacillus, respectively. One-way ANOVA with Post-hoc Turkey HSD analysis showed significant difference at the region of maxillary lateral incisor compared to other sites whereas Lactobacillishowed no significant differences between the various sites tested (p-value<0.001). Kappa statistics was performed which revealed an inter examiner reliability of 0.91. Conclusion: During orthodontic space closure, bacterial count of Streptococcus mutans showed a statistically significant difference between different sites (maxillary lateral incisor, mandibular canines, maxillary and mandibular premolars) with highest being the maxillary incisor region followed by that of mandibular canines. However, the incidence of Lactobacillusacidophilus did not show any difference between the various sites evaluated.