Search results for "Cusp"
showing 10 items of 202 documents
Gray value measurement for the evaluation of local alveolar bone density around impacted maxillary canine teeth using cone beam computed tomography
2021
Background To investigate whether any relationship between local alveolar bone density and maxillary canine impaction using gray values from cone beam computed tomography. Material and Methods The cone beam computed tomography images of 151 patients were retrospectively evaluated. Maxillary canine was defined as an impacted tooth when root formation was complete and the patient’s age older than 13 or the other side of the maxillary canine has completely erupted. Similarly, complete eruption was defined as the tooth in its expected occlusion and position. Using the cone beam computed tomography software, the region of interest which was 5 mm2 in area, was placed in the trabecular bone on cro…
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 …
Impacted maxillary canines and root resorption of adjacent teeth: a retrospective observational study
2016
Background The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means…
Orthodontic load on short maxillary implants with reduced sink depth: an experimental study.
2008
Objective The aim of this study was to investigate experimentally the positional stability and histomorphometric findings of length-reduced temporary anchorage devices (Orthosystem, length: 4 mm) with reduced sink depth. Material and methods For this purpose, four maxillary pre-molars ((2)P(2), (3)P(3)) were extracted from each of four foxhounds. After a 16-week alveolar healing period, 16 implants (four per dog) were inserted into the edentulous areas. Four implants (one per dog) were placed simultaneously in the mid-palatal area. The implants were intentionally submerged to about three-quarters of their length. After a 10-week unloaded implant healing period, the implants in the P3 areas …
Simulation study of transcatheter heart valve implantation in patients with stenotic bicuspid aortic valve
2019
Bicuspid aortic valve (BAV) anatomy has routinely been considered an exclusion in the setting of transcatheter aortic valve implantation (TAVI) because of the large dimension of the aortic annulus having a more calcified, bulky, and irregular shape. The study aims to develop a patient-specific computational framework to virtually simulate TAVI in stenotic BAV patients using the Edwards SAPIEN 3 valve (S3) and its improved version SAPIEN 3 Ultra and quantify stent frame deformity as well as the severity of paravalvular leakage (PVL). Specifically, the aortic root anatomy of n.9 BAV patients who underwent TAVI was reconstructed from pre-operative CT imaging. Crimping and deployment of S3 fram…
Three-dimensional parametric modeling of bicuspid aortopathy and comparison with computational flow predictions
2016
Bicuspid aortic valve (BAV)-associated ascending aneurysmal aortopathy (namely âbicuspid aortopathyâ) is a heterogeneous disease making surgeon predictions particularly challenging. Computational flow analysis can be used to evaluate the BAV-related hemodynamic disturbances, which likely lead to aneurysm enlargement and progression. However, the anatomic reconstruction process is time consuming so that predicting hemodynamic and structural evolution by computational modeling is unfeasible in routine clinical practice. The aim of the study was to design and develop a parametric program for three-dimensional (3D) representations of aneurysmal aorta and different BAV phenotypes starting fr…
New regression equations for predicting human teeth sizes
2015
Introduction The aims of the study were; to evaluate the applicability of the Moyers and Tanaka-Johnston Methods to individuals with a Spanish ancestry, to propose new regression equations using the lower four permanents incisors as predictors for the sum of the widths of the lower permanent canine and premolars, and to compare the new data to those from other populations. Methods A total of 359 Spanish ancestry adolescents were selected. Their dental casts were measured using a 2D computerized system. Real teeth measurements were compared with those predicted using Moyers probability tables and Tanaka and Johnston equations, and standard regression equations were then developed. Results Re…
Histological and genetic studies in patients with bicuspid aortic valve and ascending aorta complications.
2011
OBJECTIVES: Aneurysm diameter and growing rate does not represent a definite parameter for operation in bicuspid aortic valve (BAV), ascending aortic aneurysm and normal root patients. Thus, we investigated histological and immunohistochemical aspects of different segments of ascending aorta (precisely, aortic root without dilatation, aneurysmatic tubular portion, dissected ascending aorta) and genetic features of patients with BAV and ascending aorta complication (aneurysm or dissection). METHODS: Aorta tissue samples of 24 BAV patients were examined. The patients comprised of 18 men and 6 women; the mean age was 54.2 ± 14.3 years. All patients underwent composite aortic root replacement (…
Usefulness of Right Ventricular to Pulmonary Circulation Coupling as an Indicator of Risk for Recurrent Admissions in Heart Failure With Preserved Ej…
2019
In recent years, the study of right ventricular (RV) to pulmonary circulation (PC) coupling in heart failure with preserved ejection fraction (HFpEF) has been a matter of special interest. Tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) ratio has emerged as a reliable noninvasive index of RV to PC coupling. Thus, we hypothesized that TAPSE/PASP would be a predictor of readmission burden in HFpEF. One thousand one hundred and twenty seven consecutive HFpEF patients discharged for acute HF were included. In 367 patients (32.6%), PASP could not be accurately measured by echocardiography, leaving the final sample size to be 760 patients. Negative …
Use of self-organizing maps for analyzing the behavior of canines displaced towards midline under interceptive treatment
2017
Background Displaced maxillary permanent canine is one of the more frequent findings in canine eruption process and it’s easy to be outlined and early diagnosed by means of x-ray images. Late diagnosis frequently needs surgery to rescue the impacted permanent canine. In many cases, interceptive treatment to redirect canine eruption is needed. However, some patients treated by interceptive means end up requiring fenestration to orthodontically guide the canine to its normal occlusal position. It would be interesting, therefore, to discover the dental characteristics of patients who will need additional surgical treatment to interceptive treatment. Material and Methods To study the dental cha…