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Dive into the research topics where Roberto Oliveira Dantas is active.

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Featured researches published by Roberto Oliveira Dantas.


Dysphagia | 1989

Timing of Videofluoroscopic, Manometric Events, and Bolus Transit During the Oral and Pharyngeal Phases of Swallowing

Ian J. Cook; Wylie J. Dodds; Roberto Oliveira Dantas; Mark Kern; Benson T. Massey; Reza Shaker; Walter J. Hogan

The aims of this study were to evaluate and quantify the timing of events associated with the oral and pharyngeal phases of liquid swallows. For this purpose, we recorded 0–20 ml barium swallows in three groups of volunteers using videoradiographic, electromyographic, and manometric methods. The study findings indicated that a leading complex of tongue tip and tongue base movement as well as onset of superior hyoid movement and mylohyoid myoelectric activity occurred in a tight temporal relationship at the inception of swallowing. Two distinct general types of normal swallows were observed. The common “incisor-type” swallow began with the bolus positioned on the tongue with the tongue tip pressed against the upper incisors and maxillary alveolar ridge. At the onset of the “dipper-type” swallow the bolus was located beneath the anterior tongue and the tongue tip scooped the bolus to a supralingual location. Beginning with tongue-tip peristaltic movement at the upper incisors, the two swallow types were identical. Swallow events that occurred after lingual peristaltic movement at the maxillary incisors showed a volume-dependent forward migration in time that led to earlier movement of the hyoid and larynx as well as earlier opening of the upper esophageal sphincter in order to receive the large boluses that arrived sooner in the pharynx during the swallow sequence than did smaller boluses. The study findings indicated that timing of swallow events should be considered in reference to both swallow type and bolus volume. The findings also indicated an important distinction between peristaltic transit and bolus clearance.


Gastroenterology | 1990

Coordination of deglutitive glottic closure with oropharyngeal swallowing

Reza Shaker; Wylie J. Dodds; Roberto Oliveira Dantas; Walter J. Hogan; Ronald C. Arndorfer

The goals of this study were to quantify the temporal relationship between swallow-induced glottic closure and (a) signals of swallow initiation, such as hyoid bone movement, tongue base movement, and mylohyoid electrical activity; (b) pharyngeal peristalsis; (c) laryngeal elevation; (d) vestibular closure; and (e) oropharyngeal barium bolus transit. Eight normal subjects (age 20-30 yr) were studied by concurrent transnasal video laryngoscopy, pharyngeal intraluminal manometry, and submental surface electromyography. The manometric, electromyographic, and both video recordings were synchronized with one another using a specially designed event marker. Dry, 5-ml water, and 5-ml barium swallows were recorded. Frame-by-frame analysis of the video endoscopic recordings showed that deglutitive laryngeal kinetics consisted of vocal cord adduction associated with transverse approximation of the arytenoids followed by vertical approximation of arytenoids to the base of the epiglottis followed by laryngeal ascent and epiglottic descent. Onset of swallow-induced vocal cord adduction preceded the onset of hyoid bone movement, base of the tongue movement, and submental surface myoelectric activity by 0.33 +/- 0.04 (SE) s, 0.31 +/- 0.04 s, and 0.38 +/- 0.04 s, respectively. Onset of vocal cord adduction also preceded the initiation of peristalsis in the nasopharynx and its propagation to oropharynx and upper esophageal sphincter by 0.64 +/- 0.05 s, 0.82 +/- 0.05 s, and 1.08 +/- 0.04 s, respectively. The time between the onset of vocal cord adduction and their return to full opening was 2.2 +/- 0.09 s. It was concluded that (a) among events evaluated, vocal cord adduction is the initial event during the swallowing sequence; (b) laryngeal kinetics during deglutition have distinctive features, and their close coordination with other swallowing events suggests that they are an essential feature of the swallowing program; and (c) abnormal laryngeal kinetics or lack of coordination between the glottic closure mechanism and oropharyngeal bolus transport may have an important role in swallow-induced aspiration.


Dysphagia | 2015

The Influence of Food Texture and Liquid Consistency Modification on Swallowing Physiology and Function: A Systematic Review

Catriona M. Steele; Woroud Abdulrahman Alsanei; Sona Ayanikalath; Carly E. A. Barbon; Jianshe Chen; Julie A.Y. Cichero; Kim Coutts; Roberto Oliveira Dantas; Janice Duivestein; Lidia Giosa; Ben Hanson; Peter Lam; Caroline Lecko; Chelsea Leigh; Ahmed Nagy; Ashwini M. Namasivayam; Weslania Viviane do Nascimento; Inge Odendaal; Christina H. Smith; Helen Wang

Texture modification has become one of the most common forms of intervention for dysphagia, and is widely considered important for promoting safe and efficient swallowing. However, to date, there is no single convention with respect to the terminology used to describe levels of liquid thickening or food texture modification for clinical use. As a first step toward building a common taxonomy, a systematic review was undertaken to identify empirical evidence describing the impact of liquid consistency and food texture on swallowing behavior. A multi-engine search yielded 10,147 non-duplicate articles, which were screened for relevance. A team of ten international researchers collaborated to conduct full-text reviews for 488 of these articles, which met the study inclusion criteria. Of these, 36 articles were found to contain specific information comparing oral processing or swallowing behaviors for at least two liquid consistencies or food textures. Qualitative synthesis revealed two key trends with respect to the impact of thickening liquids on swallowing: thicker liquids reduce the risk of penetration–aspiration, but also increase the risk of post-swallow residue in the pharynx. The literature was insufficient to support the delineation of specific viscosity boundaries or other quantifiable material properties related to these clinical outcomes. With respect to food texture, the literature pointed to properties of hardness, cohesiveness, and slipperiness as being relevant both for physiological behaviors and bolus flow patterns. The literature suggests a need to classify food and fluid behavior in the context of the physiological processes involved in oral transport and flow initiation.


Journal of the American Geriatrics Society | 1998

Aging, Esophageal Motility, and Gastroesophageal Reflux

Eduardo Ferriolli; Ricardo Brandt de Oliveira; N. M. Matsuda; F. J. H. N. Braga; Roberto Oliveira Dantas

OBJECTIVES: To compare esophageal motility and gastroesophageal reflux characteristics in young, middle‐aged, and older healthy volunteers.


Gastroenterology | 1992

Alteration of the upper esophageal sphincter belch reflex in patients with achalasia

Benson T. Massey; Walter J. Hogan; Wylie J. Dodds; Roberto Oliveira Dantas

Some patients with achalasia have been reported to develop airway obstruction from a massively air-distended esophagus, which may represent an abnormality in the upper esophageal sphincter belch reflex. When questioned carefully, 95% of our achalasia patients reported difficulty with belching. The upper esophageal belch reflex in 23 consecutive achalasia patients and 12 healthy controls was studied using an upper esophageal sphincter sleeve manometry catheter and rapid injection of 20-50 mL of air into the midesophagus. Compared with normal subjects, achalasia patients were significantly less likely to have an esophageal belch for all volumes tested and were more likely to have an increase rather than a decrease in upper esophageal sphincter pressure in response to air injection. This study systematically documents that many achalasia patients have an alteration in the upper esophageal sphincter belch reflex that may be a contributory mechanism for some of the chest and upper airway symptoms reported by some patients during acute esophageal distension.


Digestive Diseases and Sciences | 1993

Esophageal motility impairment in Plummer-Vinson syndrome. Correction by iron treatment.

Roberto Oliveira Dantas; Marcia G. Villanova

SummaryWe report the case of a 41-year-old woman with Plummer-Vinson syndrome and an esophageal motility disorder. She complained of dysphagia and odynophagia and had cheilitis, glossitis, and hypochromic anemia. An esophageal motility study showed low amplitude of contraction and high intrabolus pressure in the esophageal body. After iron replacement, the patient was free from symptoms, and a new motility study showed increased amplitude of contraction and decreased intrabolus pressure.


Neurogastroenterology and Motility | 2010

Perception of dysphagia: lack of correlation with objective measurements of esophageal function

A. Lazarescu; G. Karamanolis; Lilian Rose Otoboni Aprile; R. de Oliveira; Roberto Oliveira Dantas; Daniel Sifrim

Background  The mechanism underlying increased perception of food bolus passage in the absence of esophageal mechanical obstruction has not been completely elucidated. A correlation between the intensity of the symptom and the severity of esophageal dysfunction, either motility (manometry) or bolus transit (impedance) has not been clearly demonstrated. The aim of this study was to analyze the correlation between objective esophageal function assessment (with manometry and impedance) and perception of bolus passage in healthy volunteers (HV) with normal and pharmacologically‐induced esophageal hypocontractility, and in patients with gastro‐esophageal reflux disease (GERD) with and without ineffective esophageal motility (IEM).


Dysphagia | 2017

Development of International Terminology and Definitions for Texture-Modified Foods and Thickened Fluids Used in Dysphagia Management: The IDDSI Framework

Julie A.Y. Cichero; Peter Lam; Catriona M. Steele; Ben Hanson; Jianshe Chen; Roberto Oliveira Dantas; Janice Duivestein; Jun Kayashita; Caroline Lecko; Joseph A. Murray; Mershen Pillay; Luis F. Riquelme; Soenke Stanschus

Dysphagia is estimated to affect ~8% of the world’s population (~590 million people). Texture-modified foods and thickened drinks are commonly used to reduce the risks of choking and aspiration. The International Dysphagia Diet Standardisation Initiative (IDDSI) was founded with the goal of developing globally standardized terminology and definitions for texture-modified foods and liquids applicable to individuals with dysphagia of all ages, in all care settings, and all cultures. A multi-professional volunteer committee developed a dysphagia diet framework through systematic review and stakeholder consultation. First, a survey of existing national terminologies and current practice was conducted, receiving 2050 responses from 33 countries. Respondents included individuals with dysphagia; their caregivers; organizations supporting individuals with dysphagia; healthcare professionals; food service providers; researchers; and industry. The results revealed common use of 3–4 levels of food texture (54 different names) and ≥3 levels of liquid thickness (27 different names). Substantial support was expressed for international standardization. Next, a systematic review regarding the impact of food texture and liquid consistency on swallowing was completed. A meeting was then convened to review data from previous phases, and develop a draft framework. A further international stakeholder survey sought feedback to guide framework refinement; 3190 responses were received from 57 countries. The IDDSI Framework (released in November, 2015) involves a continuum of 8 levels (0–7) identified by numbers, text labels, color codes, definitions, and measurement methods. The IDDSI Framework is recommended for implementation throughout the world.


Digestive Diseases and Sciences | 2004

Diminished retention of food in the proximal stomach correlates with increased acidic reflux in patients with gastroesophageal reflux disease and dyspeptic symptoms.

José Ruver L. Herculano; Luiz Ernesto de Almeida Troncon; Lilian Rose Otoboni Aprile; Eder R. Moraes; Marie Secaf; Pedro Herbert Casimiro Onofre; Roberto Oliveira Dantas; Ricardo Brandt de Oliveira

This work aimed at evaluating the intragastric distribution of food in patients with GERD and dyspepsia and its relationship to acidic reflux episodes. Gastric emptying and food retention in the proximal stomach were evaluated by scintigraphy in 12 healthy subjects and 19 patients with GERD and dyspepsia after a liquid test meal. Patients also underwent 24-hr esophageal pH monitoring, which included a 2-hr postprandial period following a similar test meal. Total gastric emptying was similar in patients and controls, whereas proximal gastric retention (AUCprox/AUCtot) was significantly decreased in patients (mean ± SD: 0.48 ± 0.07 vs. 0.56 ± 0.06; P = 0.02). Within the GERD–dyspepsia group, a significant negative correlation was found between proximal gastric retention and the number of acidic reflux episodes. We concluded that abnormally decreased retention of gastric contents in the proximal stomach after a liquid meal may contribute to the pathogenesis of acidic reflux episodes in patients with GERD and dyspepsia.


International Journal of Oral and Maxillofacial Surgery | 2010

Masticatory muscle function three years after surgical correction of class III dentofacial deformity

Luciana Vitaliano Voi Trawitzki; Roberto Oliveira Dantas; Francisco Veríssimo de Mello-Filho; W. Marques

Individuals with dentofacial deformities have masticatory muscle changes. The objective of the present study was to determine the effect of interdisciplinary treatment in patients with dentofacial deformities regarding electromyographic activity (EMG) of masticatory muscles three years after surgical correction. Thirteen patients with class III dentofacial deformities were studied, considered as group P1 (before surgery) and group P3 (3 years to 3 years and 8 months after surgery). Fifteen individuals with no changes in facial morphology or dental occlusion were studied as controls. The participants underwent EMG examination of the temporal and masseter muscles during mastication and biting. Evaluation of the amplitude interval of EMG activity revealed a difference between P1 and P3 and no difference between P3 and the control group. In contrast, evaluation of root mean square revealed that, in general, P3 values were higher only when compared with P1 and differed from the control group. There was an improvement in the EMG activity of the masticatory muscles, mainly observed in the masseter muscle, with values close to those of the control group in one of the analyses.

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Wylie J. Dodds

Pennsylvania State University

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