An Anthropometric Study of Cranio-Facial Measurements and Their Correlation with Vertical Dimension of Occlusion among Saudi Arabian Subpopulations

BACKGROUND: Determining and restoring physiological vertical dimension of occlusion (VDO) is the critical step during complete mouth rehabilitation. The improper VDO compromises the aesthetics, phonetics and functional efficiency of the prosthesis.  Various methods are suggested to determine the accurate VDO, including the facial measurements in the clinical situations with no pre-extraction records. The generalisation of correlation between the facial measurements to VDO is criticised due to gender dimorphism and racial differences. Hence, it is prudent to verify the hypothesis of facial proportion and correlation of lower third of the face to remaining craniofacial measurements in different ethnic groups. The objective of the study was to evaluate the correlation of craniofacial measurements and OVD in the Saudi-Arabian ethnic group.METHODOLOGY: Total of 228 participants from Saudi-Arabian Ethnic group were randomly recruited in this cross-sectional study. Fifteen craniofacial measurements were recorded with modified digital Vernier callipers, and OVD was recorded at centric occlusion. The obtained data were analysed by using the Spearman’s correlation and linear regression analysis.RESULTS: The Mean OVD in male participants was higher (69.25 ± 5.54) in comparison to female participants (57.41 ± 5.32).  The craniofacial measurement of Exocanthion-right labial commissure and the Mesial wall of the right external auditory canal-orbitale lateral had a strong positive correlation with VDO. The strong correlation was recorded with a trichion-upper border of right eyebrow line and trichion-Nasion only in males. Meanwhile, the length of an auricle recorded the positive correlation in female participants.CONCLUSIONS: Being simple and non-invasive technique, craniofacial measurements and linear equations could be routinely utilised to determine VDO

Visible light activated mesoporous TiO2-xNx nanocrystalline photocatalyst

Mesoporous TiO2-xNx has been prepared using template-free solvothermal synthesis with post-ammonolysis at 500°C. The characterizations using X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), N2 ad-desorption, and transmission electron microscopy (TEM) showed that the TiO2-xNx is typical mesopores anatase nanocrystalline. The nitrogen dopant causes the absorption edge of TiO2 shift to a lower energy region that enhances its visible light absorption. Under visible light irradiation, the TiO2-xNx exhibits higher activity than commercial P25 but similar activity in decoloration of methylene blue under UV irradiation. There have been great interests in porous titania for its potential application in photocatalysis, sensor, and photovoltaics. Different synthesis strategies to produce mesoporous titania has been developed using a variety of surfactant templates. The combination of the template-free solvothermal synthesis of TiO2-ST and post-ammonolysized TiO2-xNx-ST is an effective method for preparing mesoporous N-doped TiO2. The mesopores of TiO2-xNx-ST result from the aggregation of their nano-crystalline particles. The crystal anatase phase of TiO2-xNx-ST is an important feature for photocatalysis. The TiO2-xNx-ST can adsorb the visible light up to 550 nm, therefore, exhibits higher visible light activity

Desulfurization of diesel via the H2O2 oxidation of aromatic sulfides to sulfones using a tungstate catalyst

A simplified oxidative desulfurizataion (ODS) catalytic system composed of Na2 WO4, 30% H2 O2 and CH3 CO2 H has been found suitable for the deep removal of sulfur in diesel. By combining ODS and methanol extraction, the sulfur level in a commercial diesel has been reduced from 1100 ppm to 40 ppm. Treatment of model solutions of octane containing dibenzothiophene and 4,6-dimethyl dibenzothiophene with our ODS system shows 100% conversion of the thiophenes to sulfones at 70ºC in less than 1 h