PURPOSE The optic nerve (ON) sheath's role in limiting duction has been previously unappreciated. This study employed magnetic resonance imaging (MRI) to demonstrate this constraint on adduction. METHODS High-resolution, surface coil axial MRI was obtained in 11 normal adults, 14 subjects with esotropia (ET) having normal axial length (AL) < 25.8 mm, 13 myopic subjects with ET and mean AL 29....

Introduction Success of root canal treatment depends on several factors; among which, maintaining the original canal path during mechanical preparation is extremely important. This in vitro study aimed to compare apical transportation using RaCe NiTi rotary system and precurved stainless steel (SS) hand files in a reciprocating handpiece. Methods and Materials Mesiobuccal canals of 40 extract...

We give a simple new proof for the straightening law of Doubilet, Rota, and Stein using a generalization of the Laplace expansion of a determinant.

We present scaling estimates for characteristic times taulin and taubr of pulling ideal linear and randomly branched polymers of N monomers into a small hole by a force f. We show that the absorbtion process develops as sequential straightening of folds of the initial polymer configuration. By estimating the typical size of the fold involved into the motion, we arrive at the following predictio...

This study discussed the effect of heterogeneous microstructure generated through Repetitive Corrugation and Straightening (RCS) process on mechanical stress corrosion cracking behavior AA7075. As a result RCS process, significant grain refinement was obtained. The average size ranged from 126 to 59 μm, for initial condition 4 passes, respectively. yield strength hardness increased 170% 15% pas...

The purposes of this study were to evaluate the ability of a group of third-year dental students without any endodontic clinical experience to use the ProTaper Instruments (Dentsply Maillefer) to decrease the amount of straightening of curved canals on human molar teeth and to determine the incidence of instrument fractures and instrumentation time. Thirty-one undergraduate dental students in T...