background: management of canal isthmus is considered as an important factor for successful endodontic treatment. accordingly, this study was designed to determine the prevalence, location, and types of isthmus in mesial root canals of extracted mandibular molars in a sample of iranian population. materials and methods: in this cross-sectional descriptive study, 60 extracted molars with two mes...

BACKGROUND AND PURPOSE Unruptured saccular aneurysms are relatively common, occurring in 4% to 9% of autopsies. Their development at the apex region of brain artery bifurcations is attributed to a combination of structural factors and the effect of blood pressure. Collagen is a primary tension-bearing fabric of the vessel wall, and our purpose was to examine its 3-dimensional alignment at arter...

PURPOSE OF REVIEW Visual loss from optic neuropathy and ophthalmoplegia involving multiple cranial nerves are the hallmarks of an orbital apex syndrome. Historically, the terms superior orbital fissure, orbital apex, and cavernous sinus have been used to define the anatomic locations of a disease process. However, the diagnostic evaluation and management is similar for each of these entities. T...

BACKGROUND AND PURPOSE Petrous apex cephaloceles (PACs) are uncommon lesions that are usually incidental but may be symptomatic. We reviewed MR and CT studies in 10 patients with PACs to identify characteristic imaging features that facilitate their diagnosis. METHODS MR and CT studies from 10 patients with PACs were reviewed retrospectively. In each case the PAC was characterized by lesion c...

Simulation modeling is widely used to assess water contamination risk associated with pesticide use and for evaluating effectiveness of agricultural conservation practices. Currently the Agricultural Policy/Environmental eXtender (APEX) model is being used for this purpose in the USDA Conservation Effects Assessment Project (CEAP) Cropland National Assessment. In support of the CEAP modeling ef...

Situated lateral and adjacent to clivus. Petrous apex bisected by Internal auditory canal in coronal plane Anteriorly into peritubal area and posteriorly into perilabrynthine area. Anterior to the internal auditory meatus that is wedged between the posterior border of the greater wing of the sphenoid and the basilar part of the occipital bones Its borders and boundaries are marked by major bloo...

     Introduction: Objective: This study aimed to assess the possible variations in root canal anatomy and topography of the apices of first and second maxillary molars. Materials and methods: A total of 67 first and second maxillary permanent molars were collected. Access cavity was prepared and 2% methylene blue was injected. The teeth were demineralized by 5% nitric acid and cleared with met...

A detailed analysis of the coronal anatomic and CT appearances of the orbital apex is presented. In cadavers, coronal CT 9800 scans of the orbital apex and precisely corresponding cryomicrotomic sections were obtained. The CT appearance of the optic nerve, anulus of Zinn, and cranial nerves III-VI at the superior orbital fissure and orbital apex were determined. These anatomic structures were a...

PURPOSE Delineating the precise localization of prostate cancer is important in improving the diagnostic accuracy of prostate biopsy. METHODS In Juntendo University Nerima Hospital, initial 12-core or repeat 16-core biopsies were performed using a transrectal ultrasound guided transperineal prostate biopsy method. We step-sectioned prostates from radical prostatectomy specimens at 5-mm interv...

introduction: the exact measurement of the root canal length is of great importance in root canal therapy. although, determination of the root canal length through radiography is the most common method, recently electronic apex locators are being used to determine working length and decrease the number of radiographs. the purpose of this study was to compare the accuracy of an electronic apex l...