Comparison of shear bond strength of self‑etching fluoride releasing adhesives with and without pumice prophylaxis.

Context: Despite the advances in orthodontic material and treatment mechanics, the placement of fixed appliances increases the risk of enamel demineralization. The development of fluoride release adhesives has attracted considerable interests because the combined use of antimicrobials and fluoride enhances the cariostatic effect. Aim: To compare the shear bond strength (SBS) of fluoride release adhesives with established orthodontic adhesives and assess failure mode using adhesive remnant index (ARI). Settings and Design: The present study included 80 maxillary premolars which were randomly divided into four groups (n = 20) and were further subdivided into two subgroups A ‑ Pumice prophylaxis (PP) and subgroup B ‑ No PP (n = 10). Materials and Methods: Stainless steel brackets were bonded with Transbond XT, Transbond plus (TP) color change adhesive, Light Bond, and Clearfil protect bond. After debonding, the ARI was used to assess the mode of bracket failure. Statistical Analysis: The data were analyzed using two‑way analysis of variance, Post‑hoc Tukey Honest significant differences test, and Chi‑square test. Results: The mean SBS of Group 4 was comparably higher regardless of PP. Brackets bonded with TP showed a comparable SBS to conventional Transbond XT. The ARI scores were predominately 2. Conclusions: Fluoride releasing adhesives combined with antibacterial monomer can play a vital role in reducing white spot lesions by enhancing the cariostatic effect especially in noncompliant\medically compromised patients.

Corticotomy‑assisted retraction: An outcome assessment.

Background: To assess the efficiency and treatment outcome of patients treated with corticotomy‑assisted en‑masse orthodontic retraction as compared with the en‑masse retraction without corticotomy. Materials and Methods: Forty adult patients with bimaxillary protrusion requiring correction of bidental proclination constituted the sample. The study group consisted of 22 patients (male 11, female 11) willing to undergo surgery to reduce the duration of their orthodontic treatment and 18 patients (male 9, female 9) desirous of undergoing conventional orthodontic treatment without surgical intervention constituted the control group. Comparison of rate of retraction and anchor loss between the study and the control group was assessed. Results: Average rate of space closure of 1.8 mm/month in the maxilla and 1.57 mm/month in the mandible was observed in the study group compared to 1.02 mm/month in the maxilla and 0.87 mm/month in the mandible in the control group. The rate of retraction accelerated during the first 2 months of retraction. Molar anchor loss of approximately 0.6 mm occurred in the study group, and 1.8 mm occurred in the control group during the 4 months. Conclusion: The rate of retraction with study group was twice as faster when compared to the control group, accelerating during the first 2 months of retraction. There was better anchorage control with the undecorticated molar segment during the retraction period but was found to increase as time advanced.

Quantitative assessment of palatal bone thickness in an ethnic Indian population: A computed tomography study.

Context: Variations in palatal bone thickness (PBT) at various locations have caused considerable problems when using these sites for anchorage purposes. Aims: To find the comparative thickness of the palatal bone at different locations and to validate its morphology for anchorage purposes using mini-implants (MI). Settings and Design: This investigation was undertaken to compare the mean PBT and level of significance of differences between male and female subjects and between two different age-groups. Materials and Methods: The computed tomography (CT) data for 60 patients (30 males and 30 females) in two different age-groups (group A: 15-24 years; group B: 25-35 years) were imported into CAD-based medical software, (MIMICS® ; Materialise, Belgium) for multiplanar reconstruction. The measurements were made in two planes- transverse and sagittal-and at different positions in each of the planes. Statistical Analysis: The mean and standard deviations of the PBT at different points were calculated. The Student's t-test and Mann-Whitney U test were used for comparisons between the groups. Results: Significant variations were observed in the thickness of the palatal bone for both groups tested, with the anterior region at 4 mm behind the incisive papilla showing the maximum thickness. Conclusions: Despite the palatal bone being thickest in the mid-palatal suture (MPS) region, this is not the ideal site for anchorage purposes due to inadequate calcification and interposition of connective tissue, especially in young growing children. So, the alternate optimum position is the paramedian region, 3 mm lateral to the MPS and 4 mm from the incisive foramen (IF).

Evaluation of craniofacial morphology in patients with obstructive sleep apnea using lateral cephalometry and dynamic MRI.

Context: Obstructive sleep apnea (OSA) is a potentially life-threatening disorder, characterized by repeated collapse of the upper airway during sleep with cessation of breathing. The altered mouth breathing produces morphological changes in craniofacial region. Aim: This study was designed to compare and validate the craniofacial morphological characteristics in patients with OSA using lateral cephalometry and to investigate the dentofacial characteristics of patients with OSA with respect to the obstructive sites determined by dynamic magnetic resonance imaging (MRI) to more accurately clarify the pathophysiological features. Materials and Methods: 10 patients with OSA were divided into two groups of five each according to their obstructive site determined by dynamic MRI. (1) Obstruction at the retropalatal and retroglossal region (Rp + Rg group) and (2) obstruction at the retropalatal region (Rp group). Lateral cephalogram both in upright and supine position was taken for all the subjects. In addition, dynamic MRI was performed to identify the sites of obstruction of the upper airway. Statistical analysis used: Independent t-test was performed to evaluate the significant difference in the upright cephalometric variables between the study and control group and between the two groups. The changes in skeletal and soft tissue parameters with change in posture was assessed within the study and control group by paired t test. P value of ≤0.05 was considered as statistically significant. Results: The study indicated that the first group of patients with both retropalatal and retroglossal obstruction showed signs of skeletal discrepancy that predisposed to obstruction at the retroglossal level and the soft tissue components like the soft palate and tongue that contributed to retropalatal obstruction. However, the second group of patients with only retropalatal obstruction had primarily soft tissue components associated with increased BMI that contributed to retropalatal obstruction. Conclusion: Evaluation of craniofacial morphology in OSA patients is bound to help the concerned specialist in recognizing the morphological changes induced by altered sleep pattern so as to provide the appropriate treatment.