Results 231 to 240 of about 215,818 (250)

The position and topography of the apical canal constriction and apical foramen

International Endodontic Journal, 1984
Abstract. Two hundred and seventy extracted human teeth of unknown age were evaluated for apex to foramen and apex to constriction distances, in addition the topography of the apical portion of the root canal was studied under × 20 magnification. The mean A–F distance was 0.38 mm and the mean A–C distance 0.89 mm, although it must be stressed that a ...
P M, Dummer, J H, McGinn, D G, Rees
openaire   +2 more sources

The Effect of Disruption of Apical Constriction on Periapical Extrusion

Journal of Endodontics, 2005
The aim of this study was to compare the amount of apical extrusion during manual instrumentation and engine-driven rotary instrumentation in teeth with disrupted apical constriction. Fifty-two teeth were divided into two groups comprising 26 teeth each.
Alacam, T, Tinaz, AC, Uzun, O, Maden, M, Kayaoglu, GÜVEN   +4 more
openaire   +3 more sources

Validity of longitudinal sections for determining the apical constriction

International Endodontic Journal, 2016
AbstractAimTo validate the use of longitudinal sections against cross sections using micro‐CT for disclosing the topography and location of the apical constriction.MethodologySeventy extracted human teeth with 117 completely developed roots were micro‐CT scanned and reconstructed at a voxel size of 27 μm.
S, Schell, M S, Judenhofer, J G, Mannheim, M, Hülber-J, C, Löst, B J, Pichler, A, ElAyouti   +6 more
openaire   +2 more sources

Effect of preflaring on tactile detection of the apical constriction

Journal of Endodontics, 1995
The efficacy of tactile detection of the apical constriction in flared and nonflared root canals was examined in 120 root canals of adult patients. In 68 nonflared (group 1) root canals, a #15 or #20 K-file was used to detect ("feel") the apical constriction. In 52 teeth (group 2), Hedstrom files, Gates Gliden drills #2 to #4, and ultrasonic files were
A, Stabholz, I, Rotstein, M, Torabinejad
openaire   +2 more sources

Methods for the Study of Apical Constriction During Ascidian Gastrulation

2022
Gastrulation is the first major morphogenetic event during ascidian embryogenesis. Ascidian gastrulation begins with the invagination of the endodermal progenitors, a two-step process driven by individual cell shape changes of endoderm cells. During the first step, endoderm cells constrict apically, thereby flattening the vegetal side of the embryo ...
Ulla-Maj, Fiúza, Patrick, Lemaire
openaire   +2 more sources

Progressive apical pleural fibrosis: a ‘constrictive’ ventilatory defect

British Journal of Diseases of the Chest, 1988
We report two patients with bilateral apical pleural fibrosis which may be a form of benign asbestos-related pleurisy, one of these being steroid responsive. The pulmonary function defect of reduced lung volumes with raised gas transfer coefficient is characteristic and is best described as 'constrictive'.
R M, Oliver, E, Neville
openaire   +2 more sources

Neurulation continues: The parade commander is… apical constriction

Russian Journal of Developmental Biology, 2014
Neurulation is traditionally defined as the process of closure of the neural tube. New data have shown that the major driving forces ofneurulation continue to operate with the closure of the neural tube, at least until the central canal of the neural tube has formed. Owing to this, the paper proposes to distinguish two periods of neurulation. According
openaire   +2 more sources

The Cemento-Dentino-Canal Junction, the Apical Foramen, and the Apical Constriction: Evaluation by Optical Microscopy

Journal of Endodontics, 2003
The cemento-dentino-canal junction, the apical constriction, and the apical foramen are the principal reference points used to determine the apical limit for instrumentation and root canal filling. For a better understanding of these structures, the objective of this study was to evaluate histologically the localization of the cemento-dentino-canal ...
Elías Harrán, Ponce, José Antonio, Vilar Fernández   +1 more
openaire   +2 more sources

Optogenetic inhibition of apical constriction during Drosophila embryonic development

2017
Morphogenesis of multicellular organisms is driven by changes in cell behavior, which happen at precise locations and defined developmental stages. Therefore, the studying of morphogenetic events would greatly benefit from tools that allow the perturbation of cell activity with spatial and temporal precision.
G, Guglielmi, S, De Renzis
openaire   +2 more sources

Localised calcifi c constrictive pericarditis causing pseudo-apical ballooning

Acta Cardiologica, 2012
(2012). Localised calcifi c constrictive pericarditis causing pseudo-apical ballooning. Acta Cardiologica: Vol. 67, No. 5, pp. 613-614.
Johan R, Bennett, Jan, Bogaert, Bert, Ferdinande   +2 more
openaire   +2 more sources