A Prospective Cohort Study Assessing the Impact of Fixed Orthodontic Appliances on Saliva Properties and Oral Microbial Flora.

Purpose: Orthodontic treatment may introduce a risk to the integrity of enamel due to plaque accumulation and colonisation by oral microbes. This prospective cohort study observed the effect of fixed, self-ligating orthodontic appliances on saliva properties and oral microbial flora. Materials and Methods: Thirty adolescent patients were recruited (13 female, 17 male, mean age 13.97 ± 2.07 years). Saliva samples were collected before placement of fixed orthodontic appliances (T0), and 4 (T1) and 12 (T2) weeks later. Salivary pH, flow rate and buffering capacity were recorded. All saliva samples were cultured on agar plates for 2 days. Salivary prevalence of Neisseria spp., streptococci, Staphylococcus aureus, coagulase-negative staphylococci and Candida albicans were assessed. Results: High buffering capacity was reported in 21 patients at T0, 22 patients at T1 and in 28 patients at T2. Saliva flow rate also increased over time (7.08 ml/5 min at T0, 7.93 ml/5 min at T1 and 8.35 ml/5min at T2). Mean pH was 7.63 at T0, 7.67 at T1 and 7.78 at T2. There was no evidence that either pH or the number of colonies of any of the microbial species changed over time. Conclusion: The increased buffering capacity of saliva as well as the salivary flow rate after initial bonding might be protective against the development of dental caries. Current microbial findings indicate that initiation of orthodontic treatment may not be associated with significant changes in oral microbial flora

Effects of Self-ligating Orthodontic Appliances on the Periodontal Health of Adolescents: A Prospective Cohort Study.

PURPOSE To evaluate the association between orthodontic treatment with fixed appliances and periodontal health during treatment by examining gingival inflammation indices and saliva properties. MATERIALS AND METHODS Thirty consecutive orthodontic patients, aged 11-18 years old, who were eligible for fixed orthodontic appliances, were included in the study. Plaque index (PI), gingival index (GI), salivary pH and flow rate were recorded at three timepoints: immediately before placement of orthodontic fixed appliances (T0), and 1 (T1) and 3 months (T2) after bonding. RESULTS The hypothesis that PI would remain constant across timepoints was rejected. PI increased over time (0 to 1 scale, T1-T0: mean diff. = 0.10, 95% CI = 0.03, 0.18, p = 0.01; T2-T0: mean diff. = 0.16, 95% CI = 0.08, 0.24, p < 0.001). On the other hand, GI changed statistically significantly over time (p = 0.05). Patients' age was not a predictor for PI change (p = 0.93), but it was for GI (p = 0.01). As anticipated, average PI was found to be higher for the mandibular dentition by 0.10 (95% CI = 0.04, 0.16) and the labial surfaces of teeth of both jaws by 0.51 (95% CI = 0.45, 0.57). CONCLUSIONS Within the framework of the current study, orthodontic treatment appeared to affect the periodontal health of patients, but the changes were clinically negligible and not consistently statistically significant

Effect of orthodontic treatment with 4 premolar extractions compared with nonextraction treatment on the vertical dimension of the face: A systematic review.

INTRODUCTION Our aim was to assess the available evidence for the effects of orthodontic treatment with 4 premolar extractions on the skeletal vertical dimension of the face compared with nonextraction treatment. METHODS Electronic database searches (MEDLINE, EMBASE, Cochrane Oral Health Group's Trials Register, and CENTRAL) of published and unpublished literature and hand searches of eligible studies were performed, with no language or publication date restrictions. Two authors performed data extraction independently and in duplicate. Risk of bias was assessed. RESULTS After application of the eligibility criteria, 14 studies were included in this systematic review. All were retrospective. Risk of bias ranged from moderate to critical. Ten studies investigated patients with various skeletal vertical patterns and classes of malocclusion and found no difference between extraction (Ex) and nonextraction (Nonex) treatment in regard to the vertical dimension. Only 2 studies found statistically significant increases in the nonextraction groups, one in N-Me (Ex: +1.5 mm; Nonex: +5.5 mm; P <0.05) and one in SN-GoGn (Ex: -0.9°; Nonex: +0.8°; P <0.05), but without a concurrent significant change in other vertical measurements such as FMA. Two other studies showed opposite findings regarding N-Me (Ex: +2.3 mm; Nonex: +0.9 mm; P <0.05) and FMA (Ex: +0.3°; Nonex: -2.0°; P <0.05). CONCLUSIONS Although the quality of evidence ranged from moderate to low, there was considerable agreement among these studies, suggesting that orthodontic treatment with 4 premolar extractions has no specific effect on the skeletal vertical dimension. Thus, an extraction treatment protocol aiming to reduce or control the vertical dimension does not seem to be an evidence-based clinical approach

Effect of the timing of second molar bonding on the duration of the mandibular arch levelling: a randomized clinical trial.

INTRODUCTION This study investigated the effect of the timing of second molar bonding on the time required for the levelling of the mandibular dental arch. TRIAL DESIGN Single-centre two-arm parallel randomized clinical trial using random permuted blocks. Allocation concealment was achieved through sealed envelopes. There was blinding in outcome assessment, but not of patient or operator. METHODS Thirty-six patients (12-18 years old) with mild to moderate crowding and fully erupted mandibular second molars were assigned randomly (1:1 ratio) in two groups. Group A started fixed orthodontic treatment by bracket bonding in both jaws. Initial wire was 0.014" NiTi. Lower second molar tubes were bonded at the time of 0.016" x 0.022" NiTi wire placement. Group B was same as Group A, but second lower molars were bonded at the first appointment. Placement of the 0.017" x 0.025" stainless steel wire in the mandibular arch was considered the primary endpoint of the trial, indicating the completion of the levelling phase. The days required from bonding to the endpoint comprised the main outcome. Non-parametric statistics were applied. RESULTS There were two dropouts in each group. The compared groups had similar baseline characteristics regarding age, sex, overjet, overbite, space in the dental arch, average Curve of Spee (CoS), and maximum CoS. Group A tended to require more days for levelling (median: 203 days) than Group B (median: 168 days). However, this difference was not statistically significant (P = 0.128). From the tested occlusal factors, only initial overjet was found to be moderately associated with the days required to complete levelling of the mandibular arch (r = 0.45, P = 0.009). CONCLUSIONS In the frame of the current study, the duration of the levelling phase of orthodontic treatment with fixed appliances was not affected by the timing of second molar inclusion in the appliance. Future research could aim in cases with deep CoS to generalize the present findings and in larger sample sizes

A Prospective Cohort Study Assessing the Impact of Fixed Orthodontic Appliances on Saliva Properties and Oral Microbial Flora

Purpose: Orthodontic treatment may introduce a risk to the integrity of enamel due to plaque accumulation and colonisation by oral microbes. This prospective cohort study observed the effect of fixed, self-ligating orthodontic appliances on saliva properties and oral microbial flora. Materials and Methods: Thirty adolescent patients were recruited (13 female, 17 male, mean age 13.97 +/- 2.07 years). Saliva samples were collected before placement of fixed orthodontic appliances (TO), and 4 (T1) and 12 (T2) weeks later. Salivary pH, flow rate and buffering capacity were recorded. All saliva samples were cultured on agar plates for 2 days. Salivary prevalence of Neisseria spp., streptococci, Staphylococcus aureus, coagulase-negative staphylococci and Candida albicans were assessed. Results: High buffering capacity was reported in 21 patients at TO, 22 patients at T1 and in 28 patients at T2. Saliva flow rate also increased over time (7.08 ml/5 min at TO, 7.93 ml/5 min at T1 and 8.35 ml/5min at T2). Mean pH was 7.63 at TO, 7.67 at T1 and 7.78 at T2. There was no evidence that either pH or the number of colonies of any of the microbial species changed over time. Conclusion: The increased buffering capacity of saliva as well as the salivary flow rate after initial bonding might be protective against the development of dental caries. Current microbial findings indicate that initiation of orthodontic treatment may not be associated with significant changes in oral microbial flora