Search results for "Caliper"
showing 10 items of 28 documents
Prediction of the mesiodistal size of unerupted canines and premolars for a group of Romanian children: a comparative study
2013
Objectives The aim of the present study was to develop an optimization method of multiple linear regression equation (MLRE), using a genetic algorithm to determine a set of coefficients that minimize the prediction error for the sum of permanent premolars and canine dimensions in a group of young people from a central area of Romania represented by a city called Sibiu. Material and Methods To test the proposed method, we used a multiple linear regression equation derived from the estimation method proposed by Mojers, to which we adjusted regression coefficients using the Breeder genetic algorithm. A total of 92 children were selected with complete permanent teeth with no clinically visible …
New, fast, and accurate procedure to calibrate a 2-dimensional digital measurement method.
2005
Traditionally, dental casts have been measured by hand, with conventional calipers. Today, several digital methods are available for automatically measuring tooth size, but their accuracy depends on proper calibration. The purpose of this article is to introduce a fast and accurate procedure to calibrate a previously introduced 2-dimensional computerized system of measuring mesiodistal tooth size and calculating overall and anterior Bolton ratios. In this calibration method, the cast is digitized while sitting on a sheet of graph paper. The magnification of the paper in 2 axes can be easily calculated and hence the magnification of the dental cast digital image.
Evaluation of diagnostic accuracy and dimensional measurements by using CBCT in mandibular first molars
2015
Background: This study aimed to assess the diagnostic accuracy of cone beam computed tomography (CBCT) and quantitatively evaluate the morphology of mandibular first molars using CBCT. Material and Methods: Twenty-four double-rooted mandibular first molars were evaluated by NewTom VGi CBCT. The distance from the furcation and apex to the cementoenamel junction (CEJ), diameter and thickness of canal walls, the buccolingual (BL) to mesiodistal (MD) ratio (ΔD), prevalence of oval canals at different sections and taper of the canals were all determined. In order to assess the diagnostic accuracy of CBCT, distance from the furcation and apex to the CEJ and thickness of canal walls at the CEJ and…
Clinical evaluation of neodymium-iron-boron (Ne2Fe14B) rare earth magnets in the treatment of mid line diastemas
2015
Background: To evaluate the closure of midline diastema using the Neodymium-Iron-Boron magnets and to compare the treatment duration of midline diastemas with the use of magnets compared to regular orthodontic treatment. Materials and Methods: Thirty patients with age group 12 to 30 years with the midline diastema ranging from 0.5 to 3mm were selected. These patients were divided into two groups. Diastema closure in one group was accomplished by conventional method, in other group was done with Ne 2 Fe 14 B magnets. These magnets were fitted to the labial surfaces of the maxillary central incisors such a way that the opposite poles of the magnets face each other. At each appointment, study …
Evaluation of a digital radiography to estimate working length
1997
The working lengths obtained with different methods in single-rooted teeth were compared. An endodontic rule in millimeters and calipers was used as a direct method of measurement (on endodontic files). As indirect methods, measurements were taken from conventional x-rays with calipers and with a digital radiological measurement system. No statistically significant differences were obtained between the direct and indirect methods. Three vertical angulations were taken for the indirect methods (0 degree, 15 degrees, and 30 degrees). No significant differences were found between results for the two indirect methods versus the standard method except for the 30 degrees angulation, which resulte…
Caliper navigation for craniotomy planning of convexity targets.
2021
Introduction A technique to localize a radiological target on the head convexity fast and with acceptable precision is sufficient for surgeries of superficial intracranial lesions, and of help in the setting of emergency surgery, computer navigation breakdown, limited resources and education. We present a caliper technique based on fundamental geometry, with inexpensive and globally available tools (conventional CT or MRI image viewer, calculator, caliper). Methods The distances of the radiological target from two landmarks (nasion and porus acusticus externus) are assessed with an image viewer and Pythagoras’ theorem. The two distances are then marked around the landmarks onto the head of…
A Comparative Study of Cyclic Fatigue of 10 Different Types of Endodontic Instruments: an in Vitro Study
2019
Objective This study was designed to test the null hypothesis that there were no significant differences between size 25 files F360, F6 SkyTaper, Hyflex EDM, iRace, Neoniti, One Shape Protaper Next, Reciproc, Revo-S and Wave One Gold in terms of resistance to cyclic fatigue and length of broken fragments. Material and methods 300 new size 25 files of the systems studied were selected (n=30). The instruments were mechanized with a X-Smart Plus endo motor at the speed and torque recommended by the manufacturer, holding the instruments steady with a clamping mechanism, with passive adjustment and without pressure in a stainless-steel block. The time was calculated in seconds until fracture. Th…
Fracture and deformation of ProTaper Next instruments after clinical use
2018
Background The aim of this study was to evaluate the fracture and defects observed in ProTaper Next files discarded after a normal clinical use. Material and Methods 571 ProTaper Next rotary instruments were collected after clinical use from the clinic of endodontics over 12 months. The length of the files was measured using a digital caliper to determine any fracture, later all the files were evaluated under a stereomicroscope to observe defects such as unwinding, curving or fracture. The data obtained were analyzed using a chi-square and z test. Results 13.83% of the discarded files showed defects, the most frequent defect was fracture (7.53%). The highest rate of fracture was observed in…
A new technique to determine vertical dimension of occlusion from anthropometric measurement of interpupillary distance
2014
Background: A number of techniques are being practiced for the evaluation of VDO, but none of them is scientifically more accurate than other. Each method advocated has its own limitations. Objectives: The purpose of this study was to find correlation between vertical dimension of occlusion (VDO) and interpupillary distance (IPD). Material and Methods: A cross-sectional study was conducted on 400 dentate subjects comprising of 200 males and 200 females. Anthropometric measurement of VDO was recorded clinically using modified digital vernier caliper. Also, a standardized digital photograph of face was generated from the frontal aspect using a digital camera for the measurement of IPD in mill…
Panoramic radiographic study of mental foramen in selected dravidians of south Indian population: A hospital based study
2015
Background: This study aimed at documenting information on appearance, size, horizontal and vertical locations of Mental Foramen (MF) in Panoramic Radiograph. We also analyzed the age and gender differences with radiographic appearance and location of MF. We evaluated these findings in our population and co-relate with results of previous studies. Material and Methods: 1662 panoramic radiographs were evaluated, of which 245 fulfilled the inclusion criteria. Each radiograph was traced to record the horizontal and vertical locations. The size of MF was recorded using digital caliper and its appearance was determined by visual examination. Chi-square and t-test were employed. Results: The most…