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1.
Radiat Environ Biophys ; 63(1): 39-45, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38182962

RESUMEN

Three-dimensional imaging methods are widely used for evaluation of bony changes of temporomandibular joint (TMJ). Besides, lateral and posterio-anterior TMJ projections in both closed- and open-jaw positions for each temporomandibular joint are used as two-dimensional diagnostic tools. The purpose of the present study was to compare effective and mean organ absorbed doses of plain radiography techniques with those of different modalities of cone beam computed tomography (CBCT) scanning of an adult's temporomandibular joint. PCXMC 2.0 software was used to calculate mean organ and effective doses. A NewTom CBCT device (Newtom 5G XL; QR systems; Verona, Italy) was simulated at 360° rotation using a 6 × 6 cm2 FOV in standard and high-resolution modes. Lateral and posterio-anterior TMJ plain projections were simulated according to recommendations of the manufacturer of the Planmeca ProMax® 2D S3 device. Doses for both projections were simulated with Monte Carlo methods and the International Commission on radiological protection adult reference computational phantoms. The highest mean organ absorbed doses occurred in bone surfaces, salivary glands, and skull for posterio-anterior TMJ and lateral TMJ, and for CBCT scanning in all examinations. The effective doses of posterio-anterior and lateral TMJ plain radiographs were found to be higher than those of the Standard Mode-Eco Scan CBCT. Therefore, the lowest effective dose was calculated in Standard Mode-Eco Scan CBCT. It is concluded that NewTom 5G XL Standard Mode-Eco Scan CBCT can be used instead of plain radiographs (lateral and posterio-anterior TMJ) in temporomandibular joint imaging as it allows visualizing the three-dimensional structure of the temporomandibular joint as an advantage.


Asunto(s)
Tomografía Computarizada de Haz Cónico Espiral , Dosis de Radiación , Método de Montecarlo , Articulación Temporomandibular/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Fantasmas de Imagen
2.
Odontology ; 112(2): 453-459, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37819467

RESUMEN

This study was conducted to evaluate efficacy of ultrasonography (USG) in determining working length in in-vitro conditions. Twenty five access cavities of maxillary incisor teeth were opened and actual working lengths (AWL) were measured with dental operating microscope. The working length were then measured with an electronic apex locator and USG. USG and apex locator measurements were statistically analyzed using one sample t-test and compared with AWL. The mean AWL measurment was 20.68 mm. USG measured the working length slightly longer (21.09 mm) than the measurements of apex locator (20.64 mm). Statistical analysis showed that the USG method provided similar measurements to electronic apex locators and with no statistical difference with actual working length (P < .05). USG emerges as a promising method for working length measurement that allows simultaneous visualization of root tip anatomy in cases where electronic apex locators may be insufficient and there is buccal cortical bone loss.


Asunto(s)
Incisivo , Preparación del Conducto Radicular , Preparación del Conducto Radicular/métodos , Odontometría/métodos , Incisivo/diagnóstico por imagen , Cavidad Pulpar/diagnóstico por imagen
3.
Clin Oral Investig ; 27(7): 3855-3861, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37022528

RESUMEN

OBJECTIVE: To evaluate changes in the masseter muscle after orthognathic surgery using electromyography (EMG), ultrasonography (US), and ultrasound elastography (USE) in individuals with skeletal class III anomaly over long-term follow-up and compare with a control group. MATERIALS AND METHODS: The study group included 29 patients with class III dentofacial deformities scheduled to undergo orthodontic treatment and orthognathic surgery. The control group included 20 individuals with dental class I occlusion. Assessment of the masseter muscles using EMG, US, and USE was performed before orthognathic surgery (T1) and at postoperative 3 months (T2) and 1 year (T3) in the study group, and at a single time point in the control group. All assessments were performed at rest and during maximum clenching. Masseter muscle activity, dimension, and hardness were analyzed. RESULTS: Electromyographic activity of the masseter muscle during maximum clenching was increased at postoperative 1 year but did not reach control group values. On ultrasonography, the masseter muscle showed minimal changes in dimension at postoperative 1 year compared to preoperative values and remained below control group values. The postoperative increase in masseter muscle hardness at rest and during maximum clenching persisted at postoperative 1 year. CONCLUSION: The results of this study suggest that after orthognathic surgery, additional interventions and much longer follow-up are needed to ensure better muscle adaptation to the new occlusion and skeletal morphology. CLINICAL RELEVANCE: All assessment methods are useful for comprehensively evaluating changes in the masticatory muscles after orthognathic surgery.


Asunto(s)
Maloclusión de Angle Clase III , Cirugía Ortognática , Procedimientos Quirúrgicos Ortognáticos , Humanos , Músculo Masetero/diagnóstico por imagen , Maloclusión de Angle Clase III/cirugía , Mandíbula/cirugía , Procedimientos Quirúrgicos Ortognáticos/métodos , Electromiografía/métodos , Elasticidad , Músculo Temporal
4.
J Med Ultrasound ; 31(1): 22-28, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37180633

RESUMEN

Background: Bruxism is defined as recurrent masticatory muscle activity. Although there is not an agreed treatment method for bruxism, the application of botulinum toxin A (BT-A) has become a reliable lately. This study aimed to evaluate the correlation between the changes in masseter muscle thickness and clenching habits in bruxism patients treated with BT-A. Methods: Twenty-five patients, 23 females and 2 males, diagnosed with possible sleep bruxism were included in the study. The Fonseca Anamnestic Index was applied to the patients to determine their clenching habits and depression levels both before the treatment, and 6 months after it. The masseter muscle thickness was measured using ultrasonography before the treatment and 3 months and 6 months after the treatment. All the patients were injected with a total of 50 U of BT-A, 25 U to each masseter. Results: A statistically significant decrease in masseter muscle thickness was observed in the ultrasonography 3 and 6 months after the BT-A treatment. There was a statistically significant decrease in the Fonseca scores, in which the teeth clenching habits of the patients were evaluated 6 months after the treatment. Although there was a decrease in the depression levels of the patients 6 months after the treatment, this difference was not statistically significant. Conclusion: When the results of this study were evaluated, it was seen that the BT-A injections are an effective, safe, and side effect-free method in the treatment of bruxism and masseter hypertrophy.

5.
Med Sci Monit ; 28: e936160, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35754155

RESUMEN

BACKGROUND External root resorption usually does not present a clinical sign or symptom, and, therefore, diagnosis is mainly based on radiographic examination. Many studies confirmed the advantage and accuracy of cone-beam computed tomography (CBCT) in evaluating root resorptions. We aimed to evaluate the diagnostic accuracy of CBCT images of chemically induced external root resorptions on extracted human teeth taken in different voxel sizes. MATERIAL AND METHODS In this in vitro study, 36 maxillary and 36 mandibular human incisor teeth, extracted owing to periodontal disease, were used. External resorption cavities were created on the buccal and proximal surfaces by using 10% hydrochloric acid with different application periods of 10, 30, and 60 min. Resorption cavities in different depths were induced to simulate different levels of external resorption. CBCT images were taken with Planmeca Promax 3D Max CBCT (Planmeca, Helsinki, Finland) in 4 different voxel sizes: 400, 200, 150, and 100 µm. RESULTS There was no statistically significant difference between interobserver and intraobserver reliability. Higher observer agreement was obtained for 100-µm and 150-µm voxel sizes. For detection of external root resorption defects, interobserver agreement was highest for the 100-µm voxel size and when defects were located on the proximal side of the samples. The highest k values were obtained for samples kept in hydrochloric acid for 60 min. CONCLUSIONS Chemically induced resorption cavities should be used for experimental studies to better imitate clinical conditions. CBCT requirement is still ambiguous for detection of external resorptions, and more experimental and clinical studies are needed.


Asunto(s)
Resorción Radicular , Tomografía Computarizada de Haz Cónico/métodos , Humanos , Ácido Clorhídrico , Reproducibilidad de los Resultados , Resorción Radicular/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen
6.
J Craniofac Surg ; 31(7): 2049-2053, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32472876

RESUMEN

PURPOSE: The aim of this study was to examine changes in the electromyographic activity, thickness, width, and hardness of the masseter muscle from before to after orthognathic surgery. MATERIAL AND METHODS: The study included 15 patients with Class III dentofacial deformities who were treated with combined orthodontic and orthognathic surgery. Fifteen individuals with normal occlusion and no signs or symptoms of temporomandibular joint dysfunction were used as controls. All records were obtained bilaterally in the study group before surgery (T1), at 3 months after surgery (T2), and in the control group (CG) while at rest and in maximum voluntary contraction (MVC). RESULTS: There was no difference in resting masseter muscle activity between T1, T2, and CG. Resting thickness and width of the masseter muscle did not differ significantly between T1 and T2. MVC masseter muscle activity and thickness increased significantly and width decreased significantly from T1 to T2 but did not reach CG values. Muscle hardness increased from T1 to T2. CONCLUSIONS: The authors' findings indicate that despite improved muscle activity and dimensions, postoperative 3 months is still early period for adaptation of the masseter muscles to the new occlusion and skeletal morphology.


Asunto(s)
Maloclusión de Angle Clase III/diagnóstico por imagen , Músculo Masetero/diagnóstico por imagen , Adolescente , Diagnóstico por Imagen de Elasticidad , Electromiografía , Femenino , Humanos , Masculino , Maloclusión de Angle Clase III/cirugía , Contracción Muscular/fisiología , Cirugía Ortognática , Ultrasonografía , Adulto Joven
7.
Dermatol Ther ; 32(5): e13015, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31268212

RESUMEN

Oral lichen planus (OLP) is a chronic inflammatory disease with unknown etiology. There are many clinical types of OLP. OLP cases are often asymptomatic; however, atrophic or erosive forms may cause sensitivity, burning, and discomfort. The best model of the OLP treatment modality is to evaluate the restorations that may lead to oral mucosa hypersensitivity as the first step. Local corticosteroid injection therapy may be preferred to eliminate the possible systemic side effects of systemic corticosteroid medication in patients with OLP. The aim of this case series is to evaluate treatment alternatives in OLP.


Asunto(s)
Liquen Plano Oral/tratamiento farmacológico , Triamcinolona Acetonida/administración & dosificación , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Glucocorticoides/administración & dosificación , Humanos , Inyecciones Intralesiones , Liquen Plano Oral/diagnóstico , Masculino , Persona de Mediana Edad , Mucosa Bucal/patología , Adulto Joven
8.
J Craniofac Surg ; 30(8): e771-e774, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31306378

RESUMEN

INTRODUCTION: This study aimed to explore the effect of alveolar bone grafting on the clinical outcomes, health quality, and satisfaction in patients with cleft lip and palate. MATERIALS AND METHODS: Questionnaire review study was done to patients who underwent secondary alveolar bone grafting retrospectively. This study included 28 patients who underwent secondary alveolar bone grafting by harvesting graft from the anterior iliac crest, excluding one, in Oral and Maxillofacial Department, Faculty of Dentistry, Ankara University, Turkey, during the period from January 2012 to March 2016. All patients were operated using the same technique and by the same surgical team. Patients were interviewed to fill Short-Form Health Survey (SF-12) and Postsurgical Patient Satisfaction Questionnaire (PSPSQ) 6 months postoperatively. The questionnaires were used to assess the relationship between health quality and patient satisfaction. Also, grafted sites were evaluated with respect to fistula, presence of cleft palate. RESULTS: The sample consisted of 28 patients (19 females and 9 males), including 13 with bilateral clefts and 15 with unilateral clefts. The mean Physical Component Summary (PCS) and Mental Component Summary (MCS) of SF-12 scores were 54.5718 and 44.6436, respectively. The mean PSPSQ score was 36.7368. PCS scores were found to be significantly correlated with the PSPSQ scores (P ≤0.05). No correlation was found between MCS and PSPSQ scores (P >0.05). A precise and good planned surgery resulted in good satisfaction among patients with cleft lip and palate who underwent alveolar bone grafting. The patient satisfaction was correlated with the success of the operation.


Asunto(s)
Injerto de Hueso Alveolar , Labio Leporino/cirugía , Fisura del Paladar/cirugía , Injerto de Hueso Alveolar/métodos , Trasplante Óseo/métodos , Femenino , Humanos , Ilion , Masculino , Estudios Retrospectivos
9.
Am J Emerg Med ; 35(9): 1217-1221, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28343817

RESUMEN

INTRODUCTION: Pneumothorax is a pathologic condition in which air is accumulated between the visceral and parietal pleura. After clinical suspicion, in order to diagnose the severity of the condition, imaging is necessary. By using the help of Picture Archiving and Communication Systems (PACS) direct conventional X-rays are converted to gray-scale and this has become a preferred method among many physicians. METHODS: Our study design was a case-control study with cross-over design study. Posterior-anterior chest X-rays of patients were evaluated for pneumothorax by 10 expert physicians with at least 3years of experience and who have used inverted gray-scale posterior anterior chest X-ray for diagnosing pneumothorax. RESULTS: The study included posterior anterior chest X-ray images of 268 patients of which 106 were diagnosed with spontaneous pneumothorax and 162 patients used as a control group. The sensitivity of Digital-conventional X-rays was found to be higher than that of inverted gray-scale images (95% CI (2,08-5,04), p<0,01). There was no statistically significant difference between the gold standard and digital-conventional images (95% CI (0,45-2,17), p=0,20), while the evaluations of the gray-scale images were found to be less sensitive for diagnosis (95% CI (3,16-5,67) p<0,01). CONCLUSION: Inverted gray-scale imaging is not a superior imaging modality over digital-conventional X-ray for the diagnosis of pneumothorax. Prospective studies should be performed where diagnostic potency of inverted gray-scale radiograms is tested against gold standard chest CT. Further research should compare inverted grayscale to lung ultrasound to assess them as alternatives prior to CT.


Asunto(s)
Pulmón/diagnóstico por imagen , Neumotórax/diagnóstico por imagen , Radiografía Torácica/métodos , Adulto , Estudios de Casos y Controles , Estudios Cruzados , Urgencias Médicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Turquía
10.
Psychol Health Med ; 22(6): 693-700, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-27456165

RESUMEN

The aim of this study was to investigate the levels of burnout and explore the relationships between burnout and occupational participation among dentists with teaching responsibilities. Canadian Occupational Performance Measure (COPM) was used to evaluate occupational participation with questions on demographic information among 155 dentists with teaching responsibilities. Age, gender, years of experience, academic position were the factors affecting level of burnout and occupational participation. Occupational performance score was negatively correlated with emotional exhausment (r = -.731) and depersonalization (r = -.693) while positively correlated with personal accomplishment (r = .611). Occupational satisfaction scores were negatively correlated with emotional exhausment (r = -.631) and depersonalization (r = -.625) while positively correlated with personal accomplishment (r = .614). Occupational participation level can effect burnout among dentists with teaching responsibilities. Further studies with a larger sample are needed to investigate these preliminary results deeply.


Asunto(s)
Agotamiento Profesional/epidemiología , Odontólogos/psicología , Odontólogos/estadística & datos numéricos , Docentes de Odontología/estadística & datos numéricos , Satisfacción en el Trabajo , Facultades de Odontología/estadística & datos numéricos , Rendimiento Laboral/estadística & datos numéricos , Adulto , Anciano , Canadá , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
11.
Southeast Asian J Trop Med Public Health ; 47(6): 1343-52, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29634200

RESUMEN

The aim of the present study was to investigate the prevalence of burnout and occupational participation limitation among dental students in a dental school in Turkey. Four hundred fifty-eight dental students (females=153; males=305) were included in the study. The age range varied from 17-to-38 years. Maslach Burnout Inventory-Student Version (MBI-SV) and Canadian Occupational Performance Measure (COPM) were used to gather data. Descriptive analyses, t-test, and Kruskall-Wallis test for independent groups were used for data analyses. The results indicated that 26% of all the students have burnout in terms of emotional exhaustion (25%), cynicism (18%), and academic efficacy (14%). The results showed that burnout is statistically significant in relation to demographics (p<0.05). Twenty-four percent of the students showed considerably decreased occupational performance and satisfaction scores, which suggested occupational participation limitations. Occupational performance and satisfaction scores were inversely correlated with emotional exhaustion and cynicism, while directly correlated with reduced academic efficacy (p<0.05). The results of the present study indicates that burnout and occupational participation limitation can be seen among dental students. Students with burnout may also have occupational participation limitation. Enriching dental education programs with different psychological strategies may be useful for education of healthy dentists and improve the quality of oral and dental health services.


Asunto(s)
Agotamiento Profesional/psicología , Satisfacción en el Trabajo , Estudiantes de Odontología/psicología , Adolescente , Adulto , Agotamiento Profesional/diagnóstico , Femenino , Humanos , Masculino , Estrés Psicológico/complicaciones , Encuestas y Cuestionarios , Turquía , Adulto Joven
12.
Planta ; 240(6): 1287-98, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25156489

RESUMEN

MicroRNAs (miRNAs) are small non-coding class of RNAs. They were identified in many plants with their diverse regulatory roles in several cellular and metabolic processes. A number of miRNAs were involved in biotic and abiotic stress responses. Here, fungal stress responsive wheat miRNAs were analyzed by using miRNA-microarray strategy. Two different fungi (Fusarium culmorum and Bipolaris sorokiniana) were inoculated on resistant and sensitive wheat cultivars. A total of 87 differentially regulated miRNAs were detected in the 8 × 15 K array including all of the available plant miRNAs. Using bioinformatics tools, the target transcripts of responsive miRNAs were predicted, and related biological processes and mechanisms were assessed. A number of the miRNAs such as miR2592s, miR869.1, miR169b were highly differentially regulated showing more than 200-fold change upon fungal-inoculation. Some of the miRNAs were identified as fungal-inoculation responsive for the first time. The analyses showed that some of the differentially regulated miRNAs targeted resistance-related genes such as LRR, glucuronosyl transferase, peroxidase and Pto kinase. The comparison of the two miRNA-microarray analyses indicated that fungal-responsive wheat miRNAs were differentially regulated in pathogen- and cultivar-specific manners.


Asunto(s)
Ascomicetos/fisiología , Fusarium/fisiología , Regulación de la Expresión Génica de las Plantas , Genoma de Planta , MicroARNs/genética , Estrés Fisiológico/genética , Triticum/genética , Triticum/microbiología , Ontología de Genes , Genes de Plantas , MicroARNs/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados
13.
J Craniofac Surg ; 25(3): e299-301, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24777020

RESUMEN

Ameloblastic fibrodentinoma (AFD) is classified as a rarely seen benign mixed odontogenic tumor. Ameloblastic fibrodentinoma is common in children and young adults with painless swelling and mostly seen at the mandibular posterior region and usually associated with unerupted tooth. In this clinical report, an 11-year-old-boy referred to Ankara University, Faculty of Dentistry, with the complaint of pain and swelling at the mandibular posterior region, diagnosed as AFD, is presented. Extraoral examination showed swelling at the affected side. In intraoral examination, a rough painful swelling was invincible with a delayed eruption of deciduous second molar tooth. Panoramic radiography revealed well-defined radiolucency with large radiopacity above the crown of unerupted permanent second molar in the left mandible. The provisional diagnosis was complex odontoma. Biopsy resulted as AFD. The treatment achieved with total excision of the tumor and the second premolar tooth. Resorbable fixation plates were used for strengthening the excised region of the mandible. No recurrence or clinical complaints were noted during 1-year follow-up.


Asunto(s)
Neoplasias Mandibulares/diagnóstico , Tumores Odontogénicos/diagnóstico , Implantes Absorbibles , Diente Premolar/diagnóstico por imagen , Biopsia/métodos , Placas Óseas , Niño , Tomografía Computarizada de Haz Cónico/métodos , Diagnóstico Diferencial , Humanos , Masculino , Reconstrucción Mandibular/instrumentación , Diente Molar/diagnóstico por imagen , Odontoma/diagnóstico , Radiografía Panorámica/métodos , Diente Primario/diagnóstico por imagen , Diente no Erupcionado/diagnóstico por imagen
14.
Arch Oral Biol ; 159: 105892, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38241846

RESUMEN

OBJECTIVE: This study aims to investigate changes in lingula mandibulae localization before and after puberty and sex differences. DESIGN: 288 panoramic radiographs evaluated retrospectively were divided into four groups according to pubertal development: under and over 10 years old for females and under and over 11 years old for males. Four anatomic sites were used as reference points: (a) the anterior border of the ramus; (b) the posterior border of the ramus; (c) the deepest point of mandibular notch; and (d) the angulus mandibulae. The ratio of the distances from the lingula mandibulae to points (a) and (b) and the ratio of the distances from the lingula mandibulae to points (c) and (d) were determined. Two-way ANOVA was performed to assess differences between subgroups based on sex and puberty, and a Bonferroni post-hoc test was performed for multiple comparisons. RESULTS: Puberty and sex has a significant interaction effect on the vertical location of the lingula mandibulae. Postpubertal lingula mandibulae is positioned proportionally more anteriorly by prepubertal localization. In addition, the lingula mandibulae is situated more posteriorly in females compared to males. A significant interaction effect of puberty and sex was observed in relation to the vertical positioning of the lingula mandibulae. CONCLUSIONS: The spatial localization of the lingula mandibulae and its spatial displacement with age can be used both in estimating sex and the onset of puberty. Changes in the localization of lingula mandibulae according to pubertal development and sex can be used in forensic and anthropological contexts.


Asunto(s)
Mandíbula , Caracteres Sexuales , Niño , Humanos , Masculino , Femenino , Estudios Retrospectivos , Mandíbula/diagnóstico por imagen , Radiografía Panorámica , Análisis de Varianza
15.
Cranio ; 41(1): 59-68, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32936747

RESUMEN

OBJECTIVE: To evaluate occlusal splint type differences in patients with bruxism. METHODS: Seventeen controls and 51 patients were divided into three subgroups, each assigned to use a different occlusal splint (hard, soft, or semi-soft) for 3 months and assessed by ultrasonography and electromyography (EMG) before (BT) and 3 months after treatment (AT). RESULTS: EMG values in all of the occlusal splint groups were significantly lower AT than BT (p < 0.05). BT and AT EMG values in the control group did not differ. Mean muscle thicknesses in bruxism patients was greater than in controls, and the greatest muscle thickness changes occurred with the hard occlusal splint (p < 0.05). DISCUSSION: A decrease in EMG activity occurred with all three splint types and was most prominent in the hard occlusal splint group. Ultrasonographic measurements of muscle length and thickness should be used alongside EMG to measure muscle activity in bruxism patients.


Asunto(s)
Bruxismo , Ferulas Oclusales , Humanos , Bruxismo/terapia , Músculos Masticadores , Músculo Masetero/diagnóstico por imagen , Férulas (Fijadores) , Electromiografía
16.
J Endod ; 46(5): 662-667, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32151482

RESUMEN

INTRODUCTION: The aim of this study was to evaluate the amount of root canal dentin removed and apical transportation occurrence after instrumentation of mesiobuccal canals of maxillary molars with ProTaper Next (PTN [Dentsply Maillefer, Ballaigues, Switzerland]), OneShape (OS [MicroMega, Besançon, France]), and EdgeFile (EF [Edge Endo, Albuquerque, NM]) rotary systems. METHODS: Twenty-seven mesiobuccal canals of maxillary molars were used. Canals were randomly divided into 3 groups for canal preparation: PTN, EF X3, or OS (n = 9 for each group). Micro-computed tomographic imaging was used to measure apical transportation (mm) and the volume of dentin removed (mm3). The amount of dentin removed was measured for the coronal portion and for the whole canal length. Superposition of pre- and postoperative cross-sectional apical slices were used to measure apical transportation at 1 mm from the apex; the differences were evaluated using the Kruskal-Wallis test and Wilcoxon analysis. The Spearman correlation coefficient was used to display the relationship between variables for each group. The significance level was set at P < .05. RESULTS: The percentages of the amount of dentin removed on the coronal portion and the amount removed for the whole canal length were statistically similar between groups (P > .05). The average amount of apical transportation for the PTN, OS, and EF X3 were 0.197, 0.263, and 0.218 mm, respectively. Statistically, there were no significant differences between the 3 rotary instruments for apical transportation. CONCLUSIONS: The amount of dentin removed for the coronal third portion and the whole canal length was similar for the PTN, OS, and EF X3 rotary instruments. Although there were differences in the sizes of apical enlargement, no apical transportation was observed in any of the instrumentation systems.


Asunto(s)
Aleaciones Dentales , Cavidad Pulpar , Estudios Transversales , Dentina , Diseño de Equipo , Francia , Preparación del Conducto Radicular , Titanio , Microtomografía por Rayos X
17.
Dentomaxillofac Radiol ; 48(4): 20180267, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30663343

RESUMEN

OBJECTIVES: The aim of this study was to investigate the effect of dental implant materials with different physical densities on dose distribution for head and neck cancer radiotherapy planning. METHODS: Titanium (Ti), Titanium alloy (Ti-6Al-4V), Zirconia (Y-TZP), Zirconium oxide (ZrO2), Alumina (Al2O3) and polyetheretherketone (PEEK) dental implant materials were used for determination of implant material effect on dose distribution. Dental implant effect was investigated by using pencil beam convolution (PBC) algorithm of Eclipse treatment planning systems (TPS) and Monte Carlo (MC) simulation technique. 6 MV photon beam of the Varian 2300 C/D linear accelerator was simulated by EGSnrc-based BEAMnrc MC code system. RESULTS: Reasonable consistency was determined for percentage depth dose (PDD) curves between MC simulation and water phantom measurements at 6.4 MeV initial electron energy. The consistency between modelled linear accelerator PDD curve calculations and water-phantom PDD measurements were compatible within 1 % range. The dose increase in front of the dental implant calculated by MC simulation is in the range of 0.4-20.2%. We found by MC and PBC calculations that the differences in dose increase in front of the dental implant materials is in the range of 0.1-17.2% and is dependent on the physical density of the dental implant. CONCLUSIONS: Dose increase for Zirconia was noted to be maximum while PEEK implant dose increase was minimum among the whole dental implant materials studied. This study revealed that the Eclipse TPS PBC algorithm could not accurately estimate the backscatter radiation from dental implant materials.


Asunto(s)
Implantes Dentales , Neoplasias de Cabeza y Cuello , Planificación de la Radioterapia Asistida por Computador , Algoritmos , Simulación por Computador , Materiales Dentales , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Método de Montecarlo , Fantasmas de Imagen , Dosificación Radioterapéutica
18.
Artículo en Inglés | MEDLINE | ID: mdl-29273196

RESUMEN

OBJECTIVE: This study assessed the use of different voxel resolutions in a cone beam computed tomography (CBCT) unit for the detection of artificially induced periodontal bone defects created using burr, burr and chemicals, and only chemicals. STUDY DESIGN: Seven dry skulls were used in this study. In total, 65 dehiscence defects, 43 fenestration defects, and 76 control sites with no periodontal defects were examined. Images were obtained from a CBCT unit (3 D Accuitomo; J Morita Mfg. Corp., Kyoto, Japan), using 3 field-of-view (FOV) sizes (4 × 4 cm; 6 × 6 cm; and 8 × 8 cm) and 4 scan modes (standard, high-definition, high-fidelity, and low-dose). RESULTS: Overall, κ coefficients for interobserver agreement on burr-induced periodontal defects ranged from 0.336 to 0.795, with the lowest κ value (indicating a fair degree of agreement) obtained for images acquired in standard mode with a voxel size of 0.160 mm3. κ coefficients for the detection of periodontal defects were highest (indicating moderate to high degrees of interobserver agreement) for smaller voxel sizes and high-resolution images. Statistical comparison among groups (burr, burr + chemicals, and chemicals only) was performed using 1-way analysis of variance with post hoc tests. CONCLUSIONS: The CBCT scan mode may affect the diagnosis of periodontal defects. The technique used to create periodontal defects also affected diagnosis. For this kind of experiment, burr-induced or burr + chemical-induced defects should be used, rather than those induced solely using a chemical technique.


Asunto(s)
Proceso Alveolar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Enfermedades Periodontales/diagnóstico por imagen , Humanos , Técnicas In Vitro , Percloratos , Cráneo/diagnóstico por imagen
19.
Curr Eye Res ; 32(3): 241-7, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17453944

RESUMEN

PURPOSE: To evaluate the effect of uncomplicated phacoemulsification surgery on macula by optical coherence tomography (OCT). METHODS: A total of 110 eyes of 102 patients who underwent uncomplicated phacoemulsification and foldable intraocular lens implantation at Beyoglu Eye Research and Training Hospital between February and March 2005 and who were without any systemic disease, fundus or other ocular pathology were included. Postoperatively, topical prednisolone acetate (6 x 1) and ofloxacine (5 x 1) was started, and by decreasing the dosage progressively, treatment was continued for 6 weeks. Full ophthalmologic and OCT examinations were done preoperatively and at the postoperative 1st day, 1st week, 1st, 3rd, and 6th months. Mean retinal thicknesses, volumetric analyses at central fovea, superior, inferior, temporal, and nasal macular quadrants, and thinnest foveal retinal thicknesses were recorded. Preoperative and postoperative measurements were analyzed statistically by using ANOVA test, paired samples t-test with Bonferroni correction, and Pearson's correlation test. RESULTS: The mean central foveal retinal thickness was preoperatively 202.4 +/- 25.9 micro m, postoperatively 200.4 +/- 26.1 micro m at 1st day (p = 0.29), 208.4 +/- 27.6 micro m at 1st week (p = 0.29), 226.2 +/- 54.9 micro m at 1st month, 215.2 +/- 24.0 micro m at 3rd month, 213.5 +/- 29.4 micro m at 6th month (p < 0.001). Perifoveal macular thicknesses at superior, inferior, temporal, and nasal quadrants were 264.9 +/- 28.8 micro m, 266.1 +/- 29.5 micro m, 255.0 +/- 31.3 micro m, 260.3 +/- 34.0 micro m, respectively, preoperatively; 287.9 +/- 28.4 micro m, 288.0 +/- 26.3 micro m, 286.8 +/- 33.1 micro m, 272.0 +/- 32.4 micro m, respectively, at postoperative 1st month (p < 0.001). The change in mean central foveal thickness, foveal thinnest retinal thickness, mean perifoveal retinal thickness and volumetric analyses was insignificant at postoperative 1st day (p > 0.05), and significant at 1st week, 1st, 3rd, and 6th months (p < 0.05 for all measurements). CONCLUSIONS: Statistically significant increase in macular thickness was detected at postoperative early periods, after the 1st week after uncomplicated cataract operation. The increase in macular thickness starts from parafoveal regions. Longer follow-up of patients is required for the macular consequences, and different treatment protocols should be studied in a randomized controlled fashion.


Asunto(s)
Implantación de Lentes Intraoculares , Mácula Lútea/patología , Edema Macular/diagnóstico , Facoemulsificación , Complicaciones Posoperatorias , Tomografía de Coherencia Óptica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Agudeza Visual
20.
J Refract Surg ; 22(9): 906-10, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17124887

RESUMEN

PURPOSE: To compare the long-term complications of two outdated phakic intraocular lenses (PIOL) implanted in eyes with high myopia to aid development of better PIOL designs. METHODS: Sixty-two eyes of 37 patients implanted with the ZB5M anterior chamber PIOL (anterior chamber group) and 22 eyes of 14 patients implanted with Fyodorov's posterior chamber PIOL (posterior chamber group) were examined. Complications were compared after a mean follow-up of 71.15 +/- 32.17 months (range: 24 to 145 months) in the anterior chamber group and 84.14 +/- 26.43 months (range: 24 to 132 months) in the posterior chamber group (P = .07). RESULTS: At last follow-up, pupil ovalization was present in 32 (51.6%) eyes in the anterior chamber group and 1 (4.5%) eye in the posterior chamber group (P < .001), and cataract in 5 (8.1%) eyes in the anterior chamber group and 7 (31.8%) eyes in the posterior chamber group (P = .007). Phakic intraocular lens decentration, glaucoma, retinal detachment, corneal decomposition, and monocular diplopia were additional complications encountered in both groups, with no statistically significant difference. CONCLUSIONS: Proper understanding of these outdated PIOLs may be helpful in developing better PIOL designs.


Asunto(s)
Cámara Anterior/cirugía , Implantación de Lentes Intraoculares/métodos , Cristalino/fisiología , Lentes Intraoculares , Miopía/cirugía , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Diseño de Prótesis , Estudios Retrospectivos
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