Comparative assessment of dental and basal arch dimensions of passive and active self-ligating versus conventional appliances : A randomized clinical trial.

PURPOSE: In this parallel, three-arm, single-center randomized trial, the dental and basal arch dimensions after orthodontic treatment using conventional brackets and passive and active self-ligating (SL) brackets were compared. METHODS: Patients needing comprehensive orthodontic treatment were randomly allocated to the active SL, passive SL, or conventional brackets (control) group. All patients were treated with a standardized arch wires sequence. Eligibility criteria included class I malocclusion in the permanent dentition, crowding (4-6 mm), and adequate oral hygiene. The primary outcome was intermolar width, based on cone beam computed tomography (CBCT) scans. Secondary outcomes were maxillary and mandibular widths in the canines and premolars regions, dental arch depth, buccolingual inclination, and alignment duration. Blinding of outcome assessment was implemented. Patients were followed every 4 weeks until insertion of the stainless steel 0.019â€¯× 0.025 wire. Mean values were computed from CBCT sections, and data were analyzed using a one-way analysis of variance. RESULTS: In all, 66 patients (ages 18-25 years) were randomized into a 1:1:1 ratio; 7 patients dropped out before treatment initiation. Examining dental arch dimensions in the canine and premolar regions showed that expansion of the maxillary dental arch was greatest in the passive SL brackets group, less in the active SL brackets group, and lowest in the control group (P < 0.01). Changes in maxillary intermolar width between the three groups were not significant, and changes in basal arch dimensions, depth of dental and basal arches, buccolingual inclination, and alignment duration were similar in the three groups. CONCLUSIONS: Self-ligating brackets were not more effective than conventional brackets when examining intermolar width, basal transverse dimensions, depth of the arch, and alignment duration.

Effect of fluoride-releasing resin composite in white spot lesions prevention: a single-centre, split-mouth, randomized controlled trial.

INTRODUCTION: The objective of this two-arm split-mouth randomized trial, was to evaluate the ability of fluoride-releasing resin composite to prevent demineralization and white spot lesion (WSL) formation, during orthodontic treatment with fixed appliances. METHODS: Patients needing comprehensive orthodontic treatment were randomly allocated into two groups, according to the half split-mouth technique. This trial examined a total of 300 teeth in each group: the control group, in which brackets were fixed with a non-fluoride-containing adhesive resin; and the intervention group, in which brackets were fixed with a fluoride-containing adhesive resin. Eligibility criteria included Class I malocclusion in the permanent dentition, adequate oral hygiene and no missing teeth, active caries, enamel demineralization, fluorosis staining, or heavy restorations. The primary outcome was the formation of WSLs. Randomization was achieved using a computer-generated random number table; blinding of the patients, assessor, orthodontist and data analysist were achieved. The patients were followed for twelve months, during which time their teeth were checked every three months. To investigate the differences in frequencies and ranks of demineralization and WSL formation between the two groups, odds ratios were computed using mixed modelling (to compensate for the clustered nature of the data) with intervention as a fixed effect and patient as a random effect. RESULTS: Thirty-four patients (ages, 13-25 years; mean age, 17.6) were randomized into a 1:1 ratio, though four patients dropped out before the start of the treatment. The percentage of the teeth showing the effects of demineralization and WSL formation, increased from 6.3% to 15% for the control group after three and twelve months, respectively, and from 3% to 16.3% for the study group, after three to twelve months, respectively. There were no significant differences between the two groups and no interaction between time and treatment group in the visual inspections (OR 0.79; 95% CI 0.52, 1.21), in DIAGNOdent examinations (OR 0.68; 95% CI 0.43, 1.06), or in photographic images (OR 0.72; 95% CI 0.46, 1.11). No serious harm was observed during the trial. LIMITATIONS: This trial was a single-centre trial, and treatment was carried out by one orthodontist. CONCLUSIONS: Fluoride-containing resin adhesive does not have the desired preventive effect to prevent demineralization and WSL formation, during orthodontic treatment with fixed appliance. REGISTRATION AND PROTOCOL: This randomized trial was not registered, and the protocol was not published before patient recruitment. FUNDING: The University of Damascus funded this trial.

Effect of molar intrusion with temporary anchorage devices in patients with anterior open bite: a systematic review.

OBJECTIVE: The objective of the study is to assess the effect of molar intrusion with temporary anchorage devices on the vertical facial morphology and mandibular rotation during open bite treatment in the permanent dentition. METHODS: We performed a systematic review of the published data in seven electronic databases up to September 2015. We considered studies for inclusion if they were examining the effects of posterior teeth intrusion on the vertical facial morphology with open bite malocclusion in the permanent dentition. Study selection, risk of bias assessment, and data-extraction were performed in duplicate. Meta-analysis was not possible due to dissimilarity and heterogeneity among the included studies. RESULTS: Out of the 42 articles that met the initial eligibility criteria, 12 studies were finally selected. Low level of scientific evidence was identified after risk of bias assessment of the included studies with no relevant randomized controlled trial performed. Out of the 12 selected studies, five studies used miniplates and seven studies used miniscrews. Mandibular counterclockwise rotation was found to be between 2.3° and 3.9° in six studies (as sassed by mandibular plane angle, between MeGo or GoGn and SN or FH plane) while it was less than 2° in the remaining studies. CONCLUSIONS: Current weak evidence suggests that molar intrusion with temporary anchorage devices may cause mandibular counterclockwise autorotation. Future well-conducted and clearly reported multicenter randomized controlled trials that include a non-treatment control group are needed to make robust recommendations regarding the amount of mandibular rotation during open bite treatments.

The relationship between molar bite force and incisor inclination: a prospective cross-sectional study.

OBJECTIVE: To examine the relationship between molar bite force (MBF) and both the upper and lower axis inclination of the incisors. MATERIALS AND METHODS: The sample consisted of 51 participants aged between 18-27 years (mean age: 21.04±2.03), with normal occlusion and a skeletal Class I relationship, no sign of temporomandibular disorders, and no previous orthodontic treatment. Lateral cephalograms were taken and traced and the following measurements were identified: upper incisor angle (U1:SN), lower incisor angle (L1:GoMe), and the interincisal angle (U1:L1). Three sets of groups were established according to the three previously mentioned measurements (G1: decreased; G2: normal; and G3: increased). MBF was measured using a specific sensor that is sensitive to the pressure. Patients were asked to bite in the central occlusion, chew, then swallow the saliva. The mean values and standard deviation of MBF were obtained in each position and in every group then compared between related groups using the independent sample t-test. RESULTS: MBF values were significantly lower in the decreased upper incisor angle group during chewing at each side than in the normal (P=0.02 right, 0.01 left) and increased (P=0.03 right, 0.02 left) groups,while higher in the increased lower incisor group compared with the normal group (P=0.01) during chewing at the right side. In addition, there was a significant positive correlation between the upper incisor axis and MBF values both in central maximum clenching and chewing. Moreover, there was a positive correlation between the MBF and lower incisor axis during chewing, whereas a negative correlation between the MBF and interincisal angle was detected during chewing and swallowing. CONCLUSIONS: There was a linear relationship between the MBF and incisor axis. The MBF was higher when both the upper and lower inclination of incisors increased.