The aim of this study was to compare the effects of orthodontic extrusive and intrusive forces on histological changes of the human dental pulp. In this clinical trial, 52 sound upper first premolars from 26 patients scheduled for extraction for orthodontic reasons were selected. They were divided into 2 groups, based on the time intervals for histological evaluation (3 days and 3 weeks). In ea...

Given a parameterized n-dimensional SQL query template and a choice of query optimizer, a plan diagram is a color-coded pictorial enumeration of the execution plan choices of the optimizer over the query parameter space. Similarly, we can define cost diagram and cardinality diagram as the pictorial enumerations of cost and cardinality estimations of the optimizer over the same space. These thre...

study area is located in district of bajestan and ferdows cities, ne of iran. structurally, this area is part of lut block. the oldest exposed rocks, to the north of intrusive rocks and in eastern bajestan, are meta-chert, slate, quartzite, thin-bedded crystalline limestone and meta-argillite. the sedimentary units are: sardar formation (carboniferous), jamal formation (permian), sorkh shale an...

This study was conducted to investigate the nature of root resorption resulting from intrusive forces applied to the rat lower molars, by means of histological and histochemical techniques with tartrate resistant acid phosphatase (TRAP). Thirty-eight 13-week-old Wistar strain male rats were used. Intrusive force was created by a fixed appliance which was adjusted to exert an initial force of 50...

Objective: The aim of present study was to investigate the difference of torque control during intrusion force in incisors with normal, under and over-torque in lingual and labial orthodontic systems through finite element analysis. Material and Methods: 3D models of an upper right central incisor with different torques were designed in Solid Works 2006.The models were transferred to the ANSYS ...

BACKGROUND Different crown-root angulations of maxillary central incisors can be assumed as a potential reason for many underscored outcomes of orthodontic treatments. The aim of this study was to determine the effects of the different crown-root angles on stress distributions in the maxillary central incisor's periodontal ligament (PDL) during application of intrusive and retraction forces usi...

“Can we watermark without perturbing an image?” We present the salient results of the investigation carried out to find an answer to this question.