Preventive effect of ozone on the development of white spot lesions during multibracket appliance therapy

OBJECTIVE: To test the null hypotheses: (1) there is no difference in the caries protective effect of ozone and Cervitec/Fluor Protector during multibracket (MB) appliance therapy, and (2) DIAGNOdent and quantitative light-induced fluorescence (QLF) are not superior to a visual evaluation of initial caries lesions. MATERIALS AND METHODS: Twenty right-handed patients with a very poor oral hygiene who required full MB appliance therapy were analyzed during 26 months. In a split-mouth-design, the four quadrants of each patient were either treated with ozone, a combination of Cervitec and Fluor Protector, or served as untreated controls. The visible plaque index (VPI) and white spot formation were analyzed clinically. DIAGNOdent and QLF were used for a quantitative assessment of white spot formation. RESULTS: The average VPI in all four dental arch quadrants amounted to 55.6% and was independent of the preventive measure undertaken. In the quadrants treated with Cervitec/Fluor Protector, only 0.7% of the areas developed new, clinically visible white spots. This was significantly (P < .05) less than in the quadrants treated with ozone (3.2%). The lesions detected with QLF only partially corresponded to the clinically detected white spots, while DIAGNOdent proved to be unable to detect any changes at all. CONCLUSIONS: The caries protective effect of Cervitec/Fluor Protector during MB therapy was superior to ozone, and a visual evaluation of initial caries lesions was superior to both DIAGNOdent and QLF.

Survival of palatal miniscrews used for orthodontic appliance anchorage: a retrospective cohort study

INTRODUCTION The purpose of this study was to examine the overall success of miniscrews inserted in the paramedian palatal region for support of various appliances during orthodontic treatment. METHODS The patients received 1 or 2 miniscrews in the paramedian anterior palate of 8.0-mm length and 1.6-mm diameter placed during orthodontic treatment by the same experienced orthodontist. RESULTS In total, 196 patients (121 girls, 75 boys; median age, 11.7; interquartile range, 3.7) who received 384 miniscrews were evaluated. Two hundred four miniscrews were used with rapid palatal expansion appliances, 136 with appliances for distalization of posterior teeth, and 44 with other appliances, such as transpalatal arches for tooth stabilization. The overall survival of the miniscrews was excellent (97.9%) in the cases examined. Cox regression analysis showed no difference in the overall survival rates of miniscrews loaded with different appliances for sex (hazard ratio, 0.95; 95% confidence interval, 0.71-1.27; P = 0.73) after adjusting for appliance and age. CONCLUSIONS This study shows that miniscrews placed in the paramedian anterior palate for supporting various orthodontic appliances have excellent survival.

Class II treatment by extraction of maxillary first molars or Herbst appliance: dentoskeletal and soft tissue effects in comparison

AIM To compare dentoskeletal and soft tissue treatment effects of two alternative Class II division 1 treatment modalities (maxillary first permanent molar extraction versus Herbst appliance). METHODS One-hundred-fifty-four Class II division 1 patients that had either been treated with extractions of the upper first molars and a lightwire multibracket (MB) appliance (n = 79; 38 girls, 41 boys) or non-extraction by means of a Herbst-MB appliance (n = 75; 35 girls, 40 boys). The groups were matched on age and sex. The average age at the start of treatment was 12.7 years for the extraction and for 13.0 years for the Herbst group. Pretreatment (T1) and posttreatment (T2) lateral cephalograms were retrospectively analyzed using a standard cephalometric analysis and the sagittal occlusal analysis according to Pancherz. RESULTS The SNA decrease was 1.10° (p = 0.001) more pronounced in the extraction group, the SNB angle increased 1.49° more in the Herbst group (p = 0.000). In the extraction group, a decrease in SNB angle (0.49°) was observed. The soft tissue profile convexity (N-Sn-Pog) decreased in both groups, which was 0.78° more (n. s.) pronounced in the Herbst group. The nasolabial angle increased significantly more (+ 2.33°, p = 0.025) in the extraction group. The mechanism of overjet correction in the extraction group was predominantly dental (65% dental and 35% skeletal changes), while in the Herbst group it was predominantly skeletal (58% skeletal and 42% dental changes) in origin. CONCLUSION Both treatment methods were successful and led to a correction of the Class II division 1 malocclusion. Whereas for upper first molar extraction treatment more dental and maxillary effects can be expected, in case of Herbst treatment skeletal and mandibular effects prevail.

Remineralization of initial carious lesions in deciduous enamel after application of dentifrices of different fluoride concentrations

The aim of the present study was to evaluate the remineralization potential of five dentifrices with different fluoride concentrations. Initial caries lesions were created in 72 cylindrical enamel blocks from deciduous teeth. The specimens were randomly distributed among six experimental groups corresponding to six experimental periods. Each of the six volunteers carried two deciduous enamel specimens fixed in an intraoral appliance for a period of 4 weeks. They brushed their teeth and the enamel blocks at least two times a day with dentifrices containing 0 ppm (period 1), 250 ppm (period 2), and 500 ppm fluoride (period 3), respectively. A second group of volunteers (n = 6) used dentifrices with a fluoride content of 0 ppm (period 4), 1,000 ppm (period 5), or 1,500 ppm (period 6). At the end of the respective period, the mineral content was determined by transversal microradiography (TMR). The use of dentifrices containing 500 ppm fluoride (38% MR), 1,000 ppm fluoride (42% MR), and 1,500 ppm fluoride (42% MR) resulted in a statistically significant higher mineral recovery compared to the control group (0 ppm fluoride). Mineral recovery was similar after use of dentifrices containing 0 and 250 ppm fluoride (24%; 25%). It is concluded that it is possible to remineralize initial carious lesions in deciduous enamel in a similar way as it has been described for enamel of permanent teeth.

Clinical and microbiological findings at sites treated with orthodontic fixed appliances in adolescents

INTRODUCTION: Fixed orthodontic appliances can alter the subgingival microbiota. Our aim was to compare the subgingival microbiota and clinical parameters in adolescent subjects at sites of teeth treated with orthodontic bands with margins at (OBM) or below the gingival margin (OBSM), or with brackets (OBR). METHODS: Microbial samples were collected from 33 subjects (ages, 12-18 years) in treatment more than 6 months. The microbiota was assessed by the DNA-DNA checkerboard hybridization method. RESULTS: Bacterial samples were taken from 83 OBR,103 OBSM, and 54 OBM sites. Probing pocket depths differed by orthodontic type (P <0.001) with mean values of 2.9 mm (SD, 0.6) at OBSM sites, 2.5 mm (SD, 0.6) at OBM sites, and 2.3 mm (SD, 0.5) at OBR sites. Only Actinomyces israelii (P <0.001) and Actinomyces naeslundii (P <0.001) had higher levels at OBR sites, whereas Neisseria mucosa had higher levels at sites treated with OBSM or OBM (P <0.001). Aggregatibacter actinomycetemcomitans was found in 25% of sites independent of the appliance. CONCLUSIONS: Different types of orthodontic appliances cause minor differences in the subgingival microbiota (A israelii and A naeslundii) and higher levels at sites treated with orthodontic brackets. More sites with bleeding on probing and deeper pockets were found around orthodontic bands.

Three-dimensional portable document format: a simple way to present 3-dimensional data in an electronic publication

Three-dimensional (3D) models of teeth and soft and hard tissues are tessellated surfaces used for diagnosis, treatment planning, appliance fabrication, outcome evaluation, and research. In scientific publications or communications with colleagues, these 3D data are often reduced to 2-dimensional pictures or need special software for visualization. The portable document format (PDF) offers a simple way to interactively display 3D surface data without additional software other than a recent version of Adobe Reader (Adobe, San Jose, Calif). The purposes of this article were to give an example of how 3D data and their analyses can be interactively displayed in 3 dimensions in electronic publications, and to show how they can be exported from any software for diagnostic reports and communications among colleagues.

Application and comparison of classification algorithms for recognition of Alzheimer's disease in electrical brain activity (EEG)

The early detection of subjects with probable Alzheimer's disease (AD) is crucial for effective appliance of treatment strategies. Here we explored the ability of a multitude of linear and non-linear classification algorithms to discriminate between the electroencephalograms (EEGs) of patients with varying degree of AD and their age-matched control subjects. Absolute and relative spectral power, distribution of spectral power, and measures of spatial synchronization were calculated from recordings of resting eyes-closed continuous EEGs of 45 healthy controls, 116 patients with mild AD and 81 patients with moderate AD, recruited in two different centers (Stockholm, New York). The applied classification algorithms were: principal component linear discriminant analysis (PC LDA), partial least squares LDA (PLS LDA), principal component logistic regression (PC LR), partial least squares logistic regression (PLS LR), bagging, random forest, support vector machines (SVM) and feed-forward neural network. Based on 10-fold cross-validation runs it could be demonstrated that even tough modern computer-intensive classification algorithms such as random forests, SVM and neural networks show a slight superiority, more classical classification algorithms performed nearly equally well. Using random forests classification a considerable sensitivity of up to 85% and a specificity of 78%, respectively for the test of even only mild AD patients has been reached, whereas for the comparison of moderate AD vs. controls, using SVM and neural networks, values of 89% and 88% for sensitivity and specificity were achieved. Such a remarkable performance proves the value of these classification algorithms for clinical diagnostics.

Quantifying the periodicty of Inter Movement Intervals of Leg Movements

ims: Periodic leg movements in sleep (PLMS) are a frequent finding in polysomnography. Most patients with restless legs syndrome (RLS) display PLMS. However, since PLMS are also often recorded in healthy elderly subjects, the clinical significance of PLMS is still discussed controversially. Leg movements are seen concurrently with arousals in obstructive sleep apnoea (OSA) may also appear periodically. Quantitative assessment of the periodicity of LM/PLM as measured by inter movement intervals (IMI) is difficult. This is mainly due to influencing factors like sleep architecture and sleep stage, medication, inter and intra patient variability, the arbitrary amplitude and sequence criteria which tend to broaden the IMI distributions or make them even multi-modal. Methods: Here a statistical method is presented that enables eliminating such effects from the raw data before analysing the statistics of IMI. Rather than studying the absolute size of IMI (measured in seconds) we focus on the shape of their distribution (suitably normalized IMI). To this end we employ methods developed in Random Matrix Theory (RMT). Patients: The periodicity of leg movements (LM) of four patient groups (10 to 15 each) showing LM without PLMS (group 1), OSA without PLMS (group 2), PLMS and OSA (group 3) as well as PLMS without OSA (group 4) are compared. Results: The IMI of patients without PLMS (groups 1 and 2) and with PLMS (groups 3 and 4) are statistically different. In patients without PLMS the distribution of normalized IMI resembles closely the one of random events. In contrary IMI of PLMS patients show features of periodic systems (e.g. a pendulum) when studied in normalized manner. Conclusions: For quantifying PLMS periodicity proper normalization of the IMI is crucial. Without this procedure important features are hidden when grouping LM/PLM over whole nights or across patients. The clinical significance of PLMS might be eluded when properly separating random LM from LM that show features of periodic systems.

Temporary anchorage device usage: a survey among Swiss orthodontists.

BACKGROUND The aim of the survey was to obtain information on the treatment plan preferences, mechanics and characteristics of temporary anchorage device (TAD) application using a single case presented to orthodontists in Switzerland. METHODS A structured questionnaire to be completed by all study participants with case-specific (treatment plan including mechanics and TAD usage) and general questions (general fixed appliance and TAD usage as well as professional, educational and demographic questions) together with an orthodontic borderline case was utilised. The case was a female adult with dental Class II/2, deep bite and maxillary anterior crowing, who had been treated in childhood with extraction of four premolars and fixed appliance followed by wisdom tooth extraction. RESULTS The response rate was 24.4% (108 out of 443). The majority (96.3%, 104) proposed comprehensive treatment, while 3.7% (4) planned only alignment of maxillary teeth. 8.3% (9) included a surgical approach in their treatment plan. An additional 0.9% (1) combined the surgical approach with Class II mechanics. 75.1% (81) decided on distalization on the maxilla using TADs, 7.4% (8) planned various types of Class II appliances and 3.7% (4) combined distalization using TADs or headgear with Class II appliances and surgery. Palatal implants were the most popular choice (70.6%, 60), followed by mini-screws (22.4%, 19) and mini-plates on the infrazygomatic crests (7.0%, 6). The preferred site of TAD insertion showed more variation in sagittal than in transversal dimension, and the median size of mini-screws used was 10.0-mm long (interquartile range (IQR) 2.3 mm) and 2.0-mm wide (IQR 0.3 mm). CONCLUSIONS Distalization against palatal implants and then distalization against mini-screws were the most popular treatment plans. Preferred site for TAD insertion varied depending on type and size but varied more widely in the sagittal than in the transversal dimension.

The timing of significant arch dimensional changes with fixed orthodontic appliances: data from a multicenter randomised controlled trial.

OBJECTIVES To identify the timing of significant arch dimensional increases during orthodontic alignment involving round and rectangular nickel-titanium (NiTi) wires and rectangular stainless steel (SS). A secondary aim was to compare the timing of changes occurring with conventional and self-ligating fixed appliance systems. METHODS In this non-primary publication, additional data from a multicenter randomised trial initially involving 96 patients, aged 16 years and above, were analysed. The main pre-specified outcome measures were the magnitude and timing of maxillary intercanine, interpremolar, and intermolar dimensions. Each participant underwent alignment with a standard Damon (Ormco, Orange, CA) wire sequence for a minimum of 34 weeks. Blinding of clinicians and patients was not possible; however, outcome assessors and data analysts were kept blind to the appliance type during data analysis. RESULTS Complete data were obtained from 71 subjects. Significant arch dimensional changes were observed relatively early in treatment. In particular, changes in maxillary inter-first and second premolar dimensions occurred after alignment with an 0.014in. NiTi wire (P<0.05). No statistical differences in transverse dimensions were found between rectangular NiTi and working SS wires for each transverse dimension (P>0.05). Bracket type had no significant effect on the timing of the transverse dimensional changes. CONCLUSIONS Arch dimensional changes were found to occur relatively early in treatment, irrespective of the appliance type. Nickel-titanium wires may have a more profound effect on transverse dimensions than previously believed. CLINICAL SIGNIFICANCE On the basis of this research orthodontic expansion may occur relatively early in treatment. Nickel-titanium wires may have a more profound effect on transverse dimensions than previously believed.

Action of food preservatives on 14-days dental biofilm formation, biofilm vitality and biofilm-derived enamel demineralisation in situ

AIMS The aims of this double-blind, controlled, crossover study were to assess the influence of food preservatives on in situ dental biofilm growth and vitality, and to evaluate their influence on the ability of dental biofilm to demineralize underlying enamel over a period of 14 days. MATERIALS AND METHODS Twenty volunteers wore appliances with six specimens each of bovine enamel to build up intra-oral biofilms. During four test cycles of 14 days, the subjects had to place the appliance in one of the assigned controls or active solutions twice a day for a minute: negative control 0.9 % saline, 0.1 % benzoate (BA), 0.1 % sorbate (SA) and 0.2 % chlorhexidine (CHX positive control). After 14 days, the biofilms on two of the slabs were stained to visualize vital and dead bacteria to assess biofilm thickness (BT) and bacterial vitality (BV). Further, slabs were taken to determine mineral loss (ML), by quantitative light-induced laser fluorescence (QLF) and transversal microradiography (TMR), moreover the lesion depths (LD). RESULTS Nineteen subjects completed all test cycles. Use of SA, BA and CHX resulted in a significantly reduced BV compared to NaCl (p < 0.001). Only CHX exerted a statistically significant retardation in BT as compared to saline. Differences between SA and BA were not significant (p > 0.05) for both parameters. TMR analysis revealed the highest LD values in the NaCl group (43.6 ± 44.2 μm) and the lowest with CHX (11.7 ± 39.4 μm), while SA (22.9 ± 45.2 μm) and BA (21.4 ± 38.5 μm) lay in between. Similarly for ML, the highest mean values of 128.1 ± 207.3 vol% μm were assessed for NaCl, the lowest for CHX (-16.8 ± 284.2 vol% μm), while SA and BA led to values of 83.2 ± 150.9 and 98.4 ± 191.2 vol% μm, respectively. With QLF for both controls, NaCl (-33.8 ± 101.3 mm(2) %) and CHX (-16.9 ± 69.9 mm(2) %), negative values were recorded reflecting a diminution of fluorescence, while positive values were found with SA (33.9 ± 158.2 mm(2) %) and BA (24.8 ± 118.0 mm(2) %) depicting a fluorescence gain. These differences were non-significant (p > 0.05). CONCLUSION The biofilm model permited the assessment of undisturbed oral biofilm formation influenced by antibacterial components under clinical conditions for a period of 14 days. An effect of BA and SA on the demineralization of enamel could be demonstrated by TMR and QLF, but these new findings have to be seen as a trend. As part of our daily diet, these preservatives exert an impact on the metabolism of the dental biofilm, and therefore may even influence demineralization processes of the underlying dental enamel in situ.

A comparison of apical root resorption after orthodontic treatment with surgical exposure and traction of maxillary impacted canines versus that without impactions.

SUMMARY BACKGROUND/OBJECTIVES Orthodontic management of maxillary canine impaction (MCI), including forced eruption, may result in significant root resorption; however, the association between MCI and orthodontically induced root resorption (OIRR) is not yet sufficiently established. The purpose of this retrospective cohort study was to comparatively evaluate the severity of OIRR of maxillary incisors in orthodontically treated patients with MCI. Additionally, impaction characteristics were associated with OIRR severity. SUBJECTS AND METHODS The sample comprised 48 patients undergoing fixed-appliance treatment-24 with unilateral/bilateral MCI and 24 matched controls without impaction. OIRR was calculated using pre- and post-operative panoramic tomograms. The orientation of eruption path, height, sector location, and follicle/tooth ratio of the impacted canine were also recorded. Mann-Whitney U-test and univariate and multivariate linear mixed models were used to test for the associations of interest. RESULTS Maxillary central left incisor underwent more OIRR in the impaction group (mean difference = 0.58mm, P = 0.04). Overall, the impaction group had 0.38mm more OIRR compared to the control (95% confidence interval, CI: 0.03, 0.74; P = 0.04). However, multivariate analysis demonstrated no difference in the amount of OIRR between impaction and non-impaction groups overall. A positive association between OIRR and initial root length was observed (95% CI: 0.08, 0.27; P < 0.001). The severity of canine impaction was not found to be a significant predictor of OIRR. LIMITATIONS This study was a retrospective study and used panoramic tomograms for OIRR measurements. CONCLUSIONS This study indicates that MCI is a weak OIRR predictor. Interpretation of the results needs caution due to the observational nature of the present study.

The influence of striking object characteristics on the impact energy.

A common form of violence investigated in legal medicine is blunt trauma caused by striking with different objects. The injuries and medical consequences have been widely examined, whereas the forces and especially the energies acting on impact have rarely been analyzed. This study focuses on how the impact energy of different striking objects depends on their characteristics. A total of 1170 measurements of horizontal strikes against a static and relatively heavy pendulum have been acquired with 13 volunteers. The main focus was laid on how the weight, the length, and the center of mass of the different striking objects influenced the striking energy. The results show average impact energies in the range of 67.3 up to 311.5 J for men with an optimum weight of about 1.3 kg with its center of mass in the far end quarter for a 1-m-long striking object. The average values for women range from 30 to 202.6 J, with an optimum weight between 1.65 and 2.2 kg and similar settings for the center of mass as the men. Also, the impact energies are getting higher with shorter object lengths and reach a maximum at a length of about 0.3 to 0.4 m. The male volunteers' impact energy was on average by 84.2 % higher than the values of the female volunteers, where the impact masses were very similar and the impact velocities played the key role.

Are claims made in orthodontic journal advertisements evidence-supported?

OBJECTIVE To examine the supporting evidence of advertisements published in six leading orthodontic journals. MATERIALS AND METHODS The 2012-2013 printed issues of American Journal of Orthodontics and Dentofacial Orthopedics, Australian Orthodontic Journal, Journal of Orthodontics, European Journal of Orthodontics, Journal of Clinical Orthodontics, and Journal of Orofacial Orthopedics were screened for advertisements implying superior performance compared with competitor products. Advertisements were classified according to type of product, availability, and currency of supporting references. RESULTS A total of 99 unique advertisements claiming clinical benefit or superiority were identified. The overwhelming majority of the identified advertisements promoted appliance products (62.6%), orthodontic materials (14.1%), and dental operatory equipment, including imaging systems (12.1%). Advertisements were found to provide references or not regardless of the product type. Half of the advertisements referred to at least one peer-reviewed publication, whereas unpublished studies were cited by 25% of the advertisements. Most of the referenced articles were published within the past 5 years. CONCLUSIONS The scientific background of advertisements in the orthodontic literature appears limited. While surveillance of journal advertising needs to be regulated, clinicians are urged to critically appraise the claims being made in orthodontic print advertisements by consulting the associated existing evidence.