Selective hydrogenolysis of the aromatic carbon-oxygen (C-O) bonds in aryl ethers is an unsolved synthetic problem important for the generation of fuels and chemical feedstocks from biomass and for the liquefaction of coal. Currently, the hydrogenolysis of aromatic C-O bonds requires heterogeneous catalysts that operate at high temperature and pressure and lead to a mixture of products from com...

OBJECTIVE The aim of this study was to identify the procedures adopted by Brazilian orthodontists in the following situations: extraction space closure, anchorage control in case of necessary anchorage for group A and frequency of skeletal anchorage use, especially in the upper jaw. METHODS A questionnaire was sent to the e-mail address of all dentists registered in the Brazilian Federal Coun...

BACKGROUND Overeruption of an upper molar following loss of the opposing tooth is a common clinical finding. Rehabilitation can be difficult when the interocclusal space is reduced. AIM To intrude an overerupted upper first molar and replace the missing lower first molar. METHODS Buccal and palatal microscrews and a transpalatal bar were placed. The palatal miniscrew loosened shortly after ...

Conventional complete denture is the traditional treatment plan for the completely edentulous patient. Unfortunately, this treatment option has several complications, especially for the lower denture. The advance of a dental implant with attachment systems resolves many of these issues, particularly that related to the denture retention and stability. A wide variety of commercially available at...

AIM To apply dual-source multidetector computed tomography (DSCT) scanning technology in conjunction with computationally assisted segmentation in order to explore and document skeletal variation that has occurred over the course of evolution. METHODS We examined 4 divergent species of elasmobranchs with high-resolution 3rd generation DSCT. The formalin prepared species examined were: Aptycho...

In contrast to experimental evidence regarding the postorbital bar, postorbital septum, and browridge, there is exceedingly little evidence regarding the load-bearing nature of soft-tissue structures of the mammalian circumorbital region. This hinders our understanding of pronounced transformations during primate origins, in which euprimates evolved a postorbital bar from an ancestor with the p...

OBJECTIVE The main goal of this study was to optimize unilateral molar rotation correction by modifying a trans-palatal arch (TPA) design using the finite element method. DESIGN Three-dimensional analysis of different TPA designs was carried out using the finite element method. SETTING Department of Orthodontics, Tehran University of Medical Sciences, Iran. MATERIAL AND METHODS For this i...