Comparison of biochemical markers of bone metabolism between conventional labial and lingual fixed orthodontic appliances

Objectives

The applied orthodontic force causes remodeling of the periodontium through the selective release of cytokines causing resorption of bone, enabling controlled movement of the tooth. This study compared the cytokine profile between patients treated with conventional labial and lingual fixed orthodontic appliances.

Patients and Methods

The study included 80 patients in need of orthodontic treatment, out of which 40 patients were treated by the labial fixed appliance and 40 by the lingual fixed appliance. Gingival crevicular fluid (GCF) specimens were gathered from both the groups using a microcapillary pipette. The samples were collected at the beginning of the treatment and after 21 days. Enzyme-linked immunosorbent assay was performed to evaluate the cytokine levels.

Results

Interleukin (IL)-1α, 1β, 2, 8, and tumor necrosis factor-alpha (TNF-α) levels were significantly high (P < 0.001) in GCF of participants treated with conventional labial fixed appliance. IL-1α, 1β, 2, 6, 8, and TNF-α levels were significantly high (P < 0.001) in GCF of participants treated by the lingual fixed appliance. The concentrations of TNF-α and IL-1β were increased higher than other cytokines in both the treatment groups.

Conclusion

Overall, the lingual fixed appliance had higher cytokine levels than a labial fixed appliance. Analyzing the GCF cytokine levels during orthodontic treatment could provide an ideal platform for monitoring the progress of the treatment.

Profound approach to check legitimacy of an old technique used to gauge palatal rugae

Aims

The present study aimed at assessing two fixed points of reference from where the mesial and distal point of all rugae can be measured so that the exact movement of particular rugae in any direction can be evaluated and assessing the changes in the palatal rugae after orthodontic treatment.

Methods

A longitudinal study conducted among a sample of 20 (8 male and 12 female) adult patients. Pre- and post-orthodontic treatment casts of patients were obtained from the Department of Orthodontics College of Dentistry Jazan University. Antero-posterior linear distances (Technique I) between medial and lateral points of primary, secondary and tertiary rugae were measured. Also, the transverse linear distance (Technique II) between medial and lateral points of right and left rugae were measured. Technique III involved marking two fixed points and using these two points a third point is located on the medial or lateral end of rugae of right and left side in pre and post-treatment orthodontic casts. The independent sample t-test was employed to compare gender. Difference between the pre- and post-treatment mean values were checked by the paired t-test.

Results

Technique III successfully showed the statistically significant difference (P ≤ 0.05, 95% CI) in the overall pre and post-treatment values on the patients' cast (N = 20) which was not observed with a technique I and technique II.

Conclusion

The triangle created by the three reference points in the technique III was able to identify the changes in the palatine rugae more precisely than the technique I and Technique II.

Optical-vortex diagnostics via Fraunhofer slit diffraction with controllable wavefront curvature

Far-field slit diffraction of circular optical-vortex (OV) beams is efficient for measurement of the topological charge (TC) magnitude but does not reveal its sign. We show that this is because in the common diffraction schemes the diffraction plane coincides with the incident OV waist plane. Based on the examples of Laguerre-Gaussian incident beams containing a spherical wavefront component, we demonstrate that the far-field diffracted beam profile possesses an asymmetry depending on the incident wavefront curvature and the TC sign. This finding enables simple and efficient ways for the simultaneous diagnostics of the TC magnitude and sign, which can be useful in many OV applications, including OV-assisted metrology and information processing.

Mechanistic insights into controlled depolymerization of Chitosan using H-Mordenite

Kinetics of chitosan depolymerization were studied in dilute acetic acid solution, in presence of H-Mordenite (H-MOR). Rate constants for chitosan depolymerization were determined by measurement of molecular weight, using Gel permeation Chromatography (GPC). Depolymerization rate of chitosan was altered in presence of an acidic, porous material like H-MOR. Maximum concentration of H-MOR studied during process led to minimal increase in energy of activation, from 20.54 kJ/moL to 23.25 kJ/moL. Infra-red spectroscopy, adsorption studies and rheological assessment indicated adsorption /grafting of chitosan onto porous H-MOR surface as the possible mechanism for facilitation of the depolymerization process. Under extreme conditions investigated during process optimization, H-MOR resulted in a three-fold reduction in 5-Hydroxy Methyl Furfural (5-HMF) formation and over ten times decrease in glucosamine content, as compared to reactions conducted without H-MOR. Therefore, presence of H-MOR is imperative to cleave chitosan in controlled manner and obtain products of desired molecular weight, with fewer impurities.

Detection of CMB-Cluster Lensing using Polarization Data from SPTpol

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500  deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.