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Dive into the research topics where Michael J. Casas is active.

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Featured researches published by Michael J. Casas.


IEEE Transactions on Neural Systems and Rehabilitation Engineering | 2005

Investigating the stationarity of paediatric aspiration signals

Tom Chau; Doug Chau; Michael J. Casas; Glenn Berall; David J. Kenny

An aspiration signal is the time-varying anterior-posterior acceleration measured infero-anterior to the thyroid notch when foreign material enters the airway during inspiration. The hypothesis of weak stationarity is tested on aspiration signals by the reverse arrangements test. Results indicate that aspiration signals cannot be uniformly regarded as weakly stationary. Forty-five percent of the examined signals violated the stationarity hypothesis. For these signals, time-varying variance and spectral density structure are identified as major sources of nonstationarity. Stationarity test results generally corroborate qualitative clinical descriptions of aspiration. However, stationarity analysis indicates that aspiration signals are highly heterogenous, a finding which poses significant challenges to the automatic detection of aspirations by accelerometry.


Dental Traumatology | 2009

Effects of severe dentoalveolar trauma on the quality-of-life of children and parents

Teresa D. Berger; David J. Kenny; Michael J. Casas; Edward J. Barrett; Herenia P. Lawrence

BACKGROUND/AIM This investigation assessed the effects of dental trauma on the perception of pain and quality of life (QoL) of patient-parent pairs for a year following severe injuries. SAMPLE A visual analogue scale (VAS) was used to assess the pain of injury and treatment for 27 individuals 8-20 years and their parents. The Child Oral Health Quality of Life (COHQoL) survey was used to assess the effects of dental injuries on the QoL of 23 children aged 8-14 and their parents. RESULTS Mean VAS scores revealed that all patients and parents perceived the pain of initial injury to be significantly greater than pain of splint removal (P < or = 0.05) and that pain decreased in a stepwise manner from injury through emergency treatment to splint removal. The COHQoL questionnaire demonstrated a profound and continuing effect on children and their parents QoL following severe dental injury. The initial parental COHQoL score was significantly greater than the 12-month score (P < or = 0.05) in both 8-10 and 11-14- year-olds. The COHQoL results indicated a measurable reduction in the QoL of patients and parents was still present 12-months after the injuries. At the end of one-year children were still affected by the social and well-being aspects of the injury yet parents exclusively reported that one-year effects were limited to their childrens oral symptoms and functional limitations. CONCLUSIONS Severe dental injuries produce initial and ongoing pain. Detrimental effects on the QoL of both children and parents are still present at one-year and these long-term effects are different for children and parents.


Dysphagia | 1995

Durational aspects of oral swallow in neurologically normal children and children with cerebral palsy: An ultrasound investigation

Michael J. Casas; Karen A. McPherson; David J. Kenny

Little data exist on the oral management of food boluses in neurologically normal children or children with cerebral palsy (CP). Twenty children with spastic CP and 20 neurologically normal children (age range: 6.2–12.9 years) were monitored with ultrasound imaging of the oral cavity during liquid and solid bolus tasks. A lip-cup contact detector synchronized to ultrasound image output was used during liquid tasks. Data collected from recorded ultrasound images were used to assess durational aspects of the oral phase of swallowing in neurologically normal children and children with CP. Coordinated analysis of ultrasound images with lip-cup contact data allowed timing of intervals in the pre-oral and oral phases of swallowing during liquid feeding tasks. Children with CP required more time than neurologically normal children for collection, preparation, oral transit, and total oral swallow time for 5-ml liquid boluses. Total oral swallow time was longer for solid bolus tasks in children with CP. Oral transit time for solid boluses was significantly longer than for liquid boluses in neurologically normal children and children with CP.Little data exist on the oral management of food boluses in neurologically normal children or children with cerebral palsy (CP). Twenty children with spastic CP and 20 neurologically normal children (age range: 6.2–12.9 years) were monitored with ultrasound imaging of the oral cavity during liquid and solid bolus tasks. A lip-cup contact detector synchronized to ultrasound image output was used during liquid tasks. Data collected from recorded ultrasound images were used to assess durational aspects of the oral phase of swallowing in neurologically normal children and children with CP. Coordinated analysis of ultrasound images with lip-cup contact data allowed timing of intervals in the pre-oral and oral phases of swallowing during liquid feeding tasks. Children with CP required more time than neurologically normal children for collection, preparation, oral transit, and total oral swallow time for 5-ml liquid boluses. Total oral swallow time was longer for solid bolus tasks in children with CP. Oral transit time for solid boluses was significantly longer than for liquid boluses in neurologically normal children and children with CP.


Dysphagia | 1994

Swallowing/ventilation interactions during oral swallow in normal children and children with cerebral palsy

Michael J. Casas; David J. Kenny; Karen A. McPherson

Many children with cerebral palsy (CP) suffer from feeding disorders. Twenty children with spastic CP and 20 neurologically normal children (age range 6.2–12.9 years) were monitored with ultrasound imaging of the oral cavity synchronized with surface electromyographic (EMG) recordings of masseter and infrahyoid museles and respiratory inductance plethysmograph (RIP) recordings during feeding tasks. A lip-cup contact detector signaled contact of the drinking cup on the lip during liquid tasks. Children with CP required more time than normals for collection and organization of 5 ml and 75 ml liquid boluses for swallowing. The ventilatory preparation phase, recovery to baseline resting ventilatory pattern after swallowing, and total time for task completion were longer in children with CP for 5-ml and 75-ml tasks. The interval from lip-cup contact until alteration of ventilation from baseline resting ventilatory pattern was longer for children with CP during 75-ml tasks but not for 5-ml tasks. The interval from completion of the task-related cookie swallow until initiation of the next swallow was longer in children with CP than in normal children. These data provide evidence than children with CP manage solid boluses more easily than liquid boluses and small liquid boluses more easily than large liquid boluses. This investigation statistically confirms empirically based recommendations that children with CP be allowed more time to complete feeding tasks and consume small volume drinks rather than large volume drinks.Many children with cerebral palsy (CP) suffer from feeding disorders. Twenty children with spastic CP and 20 neurologically normal children (age range 6.2–12.9 years) were monitored with ultrasound imaging of the oral cavity synchronized with surface electromyographic (EMG) recordings of masseter and infrahyoid museles and respiratory inductance plethysmograph (RIP) recordings during feeding tasks. A lip-cup contact detector signaled contact of the drinking cup on the lip during liquid tasks. Children with CP required more time than normals for collection and organization of 5 ml and 75 ml liquid boluses for swallowing. The ventilatory preparation phase, recovery to baseline resting ventilatory pattern after swallowing, and total time for task completion were longer in children with CP for 5-ml and 75-ml tasks. The interval from lip-cup contact until alteration of ventilation from baseline resting ventilatory pattern was longer for children with CP during 75-ml tasks but not for 5-ml tasks. The interval from completion of the task-related cookie swallow until initiation of the next swallow was longer in children with CP than in normal children. These data provide evidence than children with CP manage solid boluses more easily than liquid boluses and small liquid boluses more easily than large liquid boluses. This investigation statistically confirms empirically based recommendations that children with CP be allowed more time to complete feeding tasks and consume small volume drinks rather than large volume drinks.


Dysphagia | 1989

Correlation of ultrasound imaging of oral swallow with ventilatory alterations in cerebral palsied and normal children: Preliminary observations

David J. Kenny; Michael J. Casas; Karen A. McPherson

Preliminary results of an investigation that synchronizes the videotaped output of a ultrasound camera and the analog data from physiological measurements of swallowing and ventilation in normal and cerebral palsied (CP) children are presented. Four cerebral palsied children and three control children undertook a single sip-swallow of 5 ml of liquid and a solid mastication-swallow sequence on three occasions according to a defined protocol. The CP children exhibited much more variability and less control of the liquid bolus than did the controls. The ultrasound image clearly demonstrates the lack of control of the posterior of the tongue in many CP children. Some parts of the sequence of oral swallow and the time to achieve maximum anterior displacement of the hyoid bone appear to be slowed. The sequential events of swallowing show less variability as the sip-swallow proceeds from the oral voluntary to pharyngeal and lower involuntary phases. This study also identified a short-latency apnea that appears to accompany a saliva (protective) swallow and a long-latency apnea that accompanies semisolid or liquid bolus (alimentary) swallows. Further investigations of normal and CP children utilizing a combined diagnostic imaging-physiological measurement approach will follow this initial study.


Dental Traumatology | 2008

Characterization of root surface periodontal ligament following avulsion, severe intrusion or extraction: preliminary observations

Manor Haas; David J. Kenny; Michael J. Casas; Edward J. Barrett

This study employed novel topographic and histological techniques to assess remaining periodontal ligament (PDL) in a convenience sample of avulsed and intruded human permanent incisors and extracted premolars. Seventeen human teeth (eight avulsed, five severely intruded and four uninjured extracted) were evaluated for the distribution and physical characteristics of adherent root surface PDL. The topographic distribution of PDL was assessed by staining roots with malachite green and determining the proportion of remaining PDL within selected regions on four aspects of each tooth. In order to characterize mechanical damage to PDL, serial transverse sections of roots were stained with hematoxylin and eosin and examined at magnifications of 40x to 800x. The sections were photographed and imaging software was used to calculate the percentage of remaining PDL in the circumference of each root section. Topographic analysis demonstrated that 54% of the PDL remained on roots of avulsed and severely intruded incisors and 36% of the PDL remained on the extracted single-rooted premolars. Examination of serial transverse root sections revealed that 58% of the PDL remained on roots of avulsed or severely intruded incisors and 54% on extracted premolars. Avulsed and severely intruded incisors demonstrated similar amounts of retained PDL. In both injuries, almost half of the root surface was denuded of PDL.


Paediatrics and Child Health | 2017

Oral health assessment practices and perceptions of North American paediatric cardiologists

Kelly J Oliver; Michael J. Casas; Peter L. Judd; Jennifer L Russell

Objective Children with cardiac defects should have good oral health, particularly prior to cardiac surgery to minimize risks of infective endocarditis. The aim of the study was to examine the oral health assessment practices of North American cardiologists. Methods Online surveys were e-mailed to 1409 cardiologists. Cardiologists without paediatric patients or practicing in centres without cardiac surgical care were excluded. Surveys addressed oral health assessment practices for paediatric cardiac patients, and perceptions of the impact of oral health on cardiac care. Results The centre response rate was 69%, individual response rate 20%. Most cardiologists (96%) reported oral health was assessed as part of cardiac care. The most common time for assessment was prior to cardiac surgery (44%), with a quarter assessing by age 1 (28%). While most oral assessments involved a dentist (59%), 17% of cardiologists performed the oral assessment without the aid of a dentist. Four-fifths of cardiologists (83%) reported cancellation of cardiac surgery due to oral disease. Cardiologists who deferred assessment until prior to surgery had the highest experience of cancellation (96%). Assessments were delayed despite the common belief (89%) that children on pre-surgical high-calorie diets are at increased risk of oral disease. Conclusion Assessments of oral health status were often deferred until immediately prior to cardiac surgery despite the cardiologists perception that children with cardiac defects were at increased risk of oral disease and prior experience of surgical cancellation due to oral disease. Paediatricians may need to facilitate early oral assessment for these children.


Journal of The Canadian Dental Association | 2003

Avulsions and intrusions: the controversial displacement injuries.

David J. Kenny; Edward J. Barrett; Michael J. Casas


Pediatric Dentistry | 2003

Long-term Outcomes of Primary Molar Ferric Sulfate Pulpotomy and Root Canal Therapy

Michael J. Casas; Michael A. Layug; David J. Kenny; Douglas H. Johnston; Peter L. Judd


Dental Traumatology | 2005

Diagnosis of ankylosis in permanent incisors by expert ratings, Periotest® and digital sound wave analysis

Karen M. Campbell; Michael J. Casas; David J. Kenny; Tom Chau

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Glenn Berall

North York General Hospital

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Tom Chau

University of Toronto

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