Biomedical subjects

N A Fox

Publications and source records attributed to N A Fox.

At least 19 recordsLinked to original sources

PubMed2004

Measuring failure of orthodontic treatment: a comparison of outcome indicators.

OBJECTIVE: To compare treatment failure rates on a sample of completed and discontinued orthodontic treatment cases as measured by PAR, IOTN and ICON to determine whether the use of a sole index would suffice. SUBJECTS AND METHOD: All patients completing or discontinuing orthodontic treatment in the hospital orthodontic departments in the Northern Region during two calendar months were identified and pre and post-treatment models were analysed. PAR scores, IOTN (DHC and AC) and ICON were recorded. RESULTS: One-hundred-and-forty-five cases were identified and 15 had incomplete records on the day of analysis. The final sample was therefore 130. The overall treatment discontinuation rate of these 130 patients was 24.6%. The treatment failure rate with respect to occlusal improvement varied from 3.1% when measured by PAR and 10.0% using ICON. With respect to residual need it varied from 0.77 to 20.1% with respect to IOTN depending on the criteria examined. The residual treatment need with respect to ICON was 17.2%. CONCLUSIONS: Different occlusal indices give differing failure rates when used on the same patients with ICON being the most critical index. We felt that ICON was the most valid with respect to identifying treatment failure. Its use would enable international comparison of results.

Adolescent↗

PubMed2002

A comparison of the index of complexity outcome and need (ICON) with the peer assessment rating (PAR) and the index of orthodontic treatment need (IOTN).

AIM: To evaluate any relationship between ICON, IOTN and PAR. To establish whether or not ICON could replace these indices as a measure of orthodontic treatment complexity, outcome and need. METHOD: The study models of 55 consecutively treated cases were examined and PAR, IOTN and ICON recorded. RESULTS: The study showed significant correlations between IOTN and ICON with respect to need and PAR and ICON with respect to outcome. CONCLUSION: It appears that ICON does reflect UK opinion and the current study provides some evidence that ICON may effectively replace PAR and IOTN as a means of determining need and outcome.

Analysis of Variance↗

PubMed2002

The long-term benefits of orthodontic treatment.

OBJECTIVE: This study aimed to evaluate post-treatment changes at least five years out of retention in a cohort of 100 consecutively started patients treated by a postgraduate student in a UK orthodontic department. DESIGN: Analysis of study models using recognised occlusal indices. Setting Patients initially treated at Newcastle Dental Hospital were recalled for record collection. MATERIALS AND METHODS: Study models and clinical photographs were taken for each patient attending for post-retention records. Weighted Peer Assessment Rating (PAR) Index and Index of Orthodontic Treatment Need (IOTN) scores were recorded for cases at the beginning, end and at least 5 years post-retention. Main outcome measures Post-treatment changes were evaluated using PAR Index and IOTN to evaluate extent and likelihood of change and to compare treatment modalities. RESULTS: Seventy-eight patients attended for post-retention records. Overall PAR reduction immediately post-treatment was 68.6% and at a mean of 6.5 years post-retention was 55.5%. Dual arch fixed appliance treatments achieved the greatest reduction in PAR score, and maintained the reduction beyond the retention period better than other treatment modalities. Eighty-four per cent of the cohort still had some demonstrable improvement after a mean of 6.5 years post-retention. There was a residual need for treatment in 8% of cases on aesthetic grounds and in 24% of cases on dental health grounds. CONCLUSIONS: Occlusal deterioration after orthodontic treatment is almost universal. Dual arch fixed appliance treatment provides the best post-treatment and post-retention result.

Cohort Studies↗

PubMed2001

Temperamental contributions to social behavior: the moderating roles of frontal EEG asymmetry and gender.

OBJECTIVES: Infant temperament is thought to provide one of the fundamental bases for social and emotional development. Few studies have examined the direct and indirect influences of early temperament and physiological disposition on later development. METHOD: This article presents results of a longitudinal study that took place between the years 1989 and 1996 in which the relations between maternal reports of negative reactivity at 9 months of age and maternal ratings and laboratory observations of social wariness and sociability at 4 years of age (n = 97) were examined. Also examined were the moderating roles of (1) frontal electroencephalogram (EEG) asymmetry as assessed at 9 months of age and (2) the child's gender. RESULTS: Negative reactivity predicted social wariness for infants with right frontal EEG asymmetry, but not for those with left frontal EEG asymmetry and for boys but not girls. The only significant predictor of sociability was gender. Specifically, at 4 years of age girls were rated higher on the measure of sociability than were boys. CONCLUSION: The findings are discussed in terms of the roles of frontal EEG asymmetry and gender in moderating the impact of temperamental negative reactivity on later social behavior.

Adult↗

PubMed2001

Violence exposure among school-age children in foster care: relationship to distress symptoms.

OBJECTIVE: To describe the amount and nature of violence exposure and examine the relationship between violence exposure and distress symptoms among children in foster care. METHOD: Violence exposure and distress symptoms were evaluated in interviews, conducted between July 1996 and March 1998, of 300 children from Los Angeles County living in out-of-home placement. RESULTS: Interviews were successfully completed in 91% of eligible children. The majority of children (85%) reported having been a witness to violence, and 51% had been a victim of violence during their lifetime. Of these youths, 54% and 41%, respectively, reported having been exposed to such violence in the past 6 months. Girls, victims of assaultive violence and weapon related violence, and those reporting exposure to mild violence were more likely (p < .05) to have higher levels of distress symptoms than those without such characteristics, after age was controlled for. CONCLUSIONS: Children in foster care continue to have high levels of violence exposure, even after removal from their biological parents' home. The relationship between violence exposure and distress symptoms underscores the need for clinicians to inquire about multiple forms of violence exposure among children living in out-of-home placement.

Adolescent↗

PubMed2001

Association of DRD4 with attention problems in normal childhood development.

Several previous studies found an association of clinically diagnosed attention deficit hyperactivity disorder with long alleles of a variation in the DRD4 dopamine receptor gene exon III coding sequence. We evaluated the DRD4 polymorphism in a non-clinically selected sample of children for whom maternal reports of attention problems were available at 4 and 7 years of age. There was a significant elevation in attention problem scores in children carrying DRD4 long alleles that accounted for 3-4% of total variation at each age and for 5-7% of the temporally stable component of the phenotype. Our results show that the DRD4 gene influences normal as well as pathological attention processes, and the results highlight the utility of longitudinal measurements in psychiatric genetics.

Attention Deficit Disorder with Hyperactivity↗

PubMed2000

Developmental changes in heart period and high-frequency heart period variability from 4 months to 4 years of age.

Cardiac measures of heart period and high-frequency heart period variability are increasingly employed as dependent variables in studies of social and emotional development in infancy and childhood. This study describes significant developmental increases in these measures in a longitudinal sample assessed at 4, 9, 14, 24, and 48 months of age. In addition, developmental changes in the characteristics of the heart period power spectra are described. These changes have implications for the quantification of high-frequency heart period variability in infancy and childhood. First, shorter analysis epoch lengths may be used for younger infants. Second, the commonly used high-frequency band for infants (0.24-1.04 Hz) appears to reach its practical limit at an age of around four years. Findings are discussed in relation to the design of developmental psychophysiological studies.

Age Factors↗

PubMed2000

Frontal electrocortical and cardiovascular reactivity during happiness and anger.

The present study investigated electrocortical and cardiovascular reactivity during positive and negative emotion, and examined the relation of asymmetric frontal lobe activation to cardiovascular responses. Participants were 30 healthy, right-handed university students (mean age, 23.9; 60% female; 76% Caucasian). Electroencephalographic (EEG), blood pressure (BP), and heart rate (HR) responses were assessed while subjects engaged in laboratory tasks (personally-relevant recall tasks and film clips) designed to elicit happiness or anger. Happiness-inducing tasks evoked more prominent left than right frontal EEG activation, and greater left frontal EEG activation than anger-inducing tasks. However, anger-inducing tasks were, on average, associated with comparable left and right frontal EEG activation. Irrespective of emotional valence, cardiovascular activation was more pronounced during personally-relevant recall tasks than during the viewing of film clips. During anger recall, both greater left frontal EEG response (r=-0.46, P<0.02) and greater right frontal EEG response (r=-0.45, P<0.02) were correlated significantly with increased HR reactivity during the task. In addition, a right lateralized frontal EEG response during anger-inducing tasks was associated with greater concomitant systolic BP (P<0.03) and diastolic BP (P<0.008) reactivity. Exploratory analyses also indicated that men who displayed a left lateralized frontal EEG response during happiness-inducing tasks showed the greatest concomitant systolic BP and HR reactivity (P's<0.03). These findings suggest that asymmetric frontal EEG responses to emotional arousal may elicit different patterns of cardiovascular reactivity in healthy adults.

Adult↗

PubMed2000

Preschool children's exposure to violence: relation of behavior problems to parent and child reports.

A group of 155 parents and their preschool children attending Head Start reported on the children's exposure to community violence, level of distress symptoms, and behavioral problems. The behavioral correlates of exposure were found to differ according to exposure modality: internalizing problems were more likely in children who witnessed violence, and externalizing problems in those victimized by violence. Issues regarding self-reports by preschool children are highlighted, and clinical and research implications discussed.

Adult↗

PubMed2000

Stability and change of attachment at 14, 24, and 58 months of age: behavior, representation, and life events.

Stability and change of attachment was examined longitudinally in a group of 48 children at 14, 24, and 58 months of age. Whereas attachment classifications showed stability between 14 and 24 months, lack of stability was the case between either 14 or 24 months and 58 months. Mothers of children who did not exhibit stability of attachment reported more negative and less positive life events. No correspondence was found between attachment classification at 14 or 24 months and mental representations at 58 months. However there was agreement between representational and behavioral measures of attachment at 58 months, where mental representations of attachment appeared to mirror and complement behavioral classification of the attachment relationship with the mother. Evidence for continuity of attachment from infancy to childhood internal representations was found only in a subgroup of children who showed stability of secure attachment between infancy and 58 months of age. These children exhibited greater Emotional Openness in the SAT at 4.5 years. Findings are discussed in terms of different positions in attachment theory and research regarding the stability and change of attachment relationships.

Anxiety, Separation↗

PubMed1999

Effects of acute prednisone administration on memory, attention and emotion in healthy human adults.

We conducted a double-blind study in order to examine the effects of high doses of prednisone on memory, attention and emotion in humans. A total of 24 healthy undergraduate males self-administered either 160 mg of prednisone (n = 12) or a placebo (n = 12) for 4 consecutive days. We examined group differences in mood, regional brain electrical activity (EEG), the startle eyeblink response, memory recall and performance on an attention task after 4 days of treatment. We found significant group differences on measures of mood and frontal EEG alpha activity on 4-day treatment. Subjects treated with prednisone exhibited a significantly greater increase in self-reported negative emotion and greater relative right frontal EEG alpha activity on 4-day treatment compared with adults in the placebo group. We also found that subjects treated with prednisone recalled fewer objects on the memory task following treatment. No significant group differences were found on posterior EEG activity, the startle eyeblink measure, or the attention measure. These findings suggest that administration of high doses of exogenous prednisone may facilitate the experience of negative emotion and shifts in frontal EEG activity, and impair some aspects of cognitive functioning in humans. The multiple roles of glucocorticoids in memory, attention and emotion are discussed.

Adolescent↗

PubMed1999

The relations between temperament and empathy in 2-year-olds.

The role of infant and toddler temperament in the prediction of empathy in 2-year-old children was examined. Assessments of temperament included reactivity and affect observed at 4 months of age, as well as inhibition at Age 2. Empathy was measured in 2-year-old children's responses to simulations of distress performed by their mothers and by an unfamiliar person. Children showed relatively more concern for the mother's distress, but they were also responsive to unfamiliar victims. Infants who were unreactive and showed little affect also showed less empathy toward the unfamiliar adult almost 2 years later. Inhibition toward an unfamiliar adult (but not toward the mother) at 2 years of age was negatively related to empathy. Inhibited temperament may thus have a major impact on young children's empathy in unfamiliar contexts. Findings also highlight the need to consider early underarousal as another dimension of temperament that may dampen expressions of empathic concern.

Adult↗

PubMed1999

Behavioral and psychophysiological correlates of self-presentation in temperamentally shy children.

We examined temporal changes in behavior, regional brain electrical activity (EEG), heart rate, cardiac vagal tone, the startle eyeblink response, and salivary cortisol during a task designed to elicit self-presentation anxiety in a group of 7-year-olds, some of whom were classified as temperamentally shy. We found that temperamentally shy children displayed a significantly greater increase in anxious behavior, a greater increase in right, but not left, frontal EEG activity, and a greater increase in heart rate as the task became more demanding compared with their nonshy counterparts. However, the results failed to reveal any significant group differences on the startle eyeblink and salivary cortisol measures. The present findings extend our prior work, in which we found distinct patterns of psychophysiological activity on baseline measures, to differences on psychophysiological measures collected concurrently during a socially evaluative situation in temperamentally shy children.

Analysis of Variance↗

PubMed1998

Fear-potentiated startle responses in temperamentally different human infants.

Previous research has indicated that 4-month-old human infants who exhibit high degrees of motor activity and negative affect in response to the presentation of unfamiliar auditory and visual stimuli are likely to display behavioral inhibition as toddlers, while 4-month-old infants who display high degrees of motor activity and positive affect in response to the same stimuli are likely to be behaviorally exuberant toddlers. The present study examined baseline and fear-potentiated startle eyeblink responses during a stranger-approach paradigm at age 9 months in a group of infants, some of whom displayed high motor activity and negative affect and some of whom displayed high motor activity and positive affect at 4 months. The analyses revealed that the high motor/high negative group of infants exhibited a significantly greater increase in fear-potentiated startle amplitude at 9 months compared with the high motor/high positive group. There were no differences among groups of infants on baseline startle responses. These findings suggest that the origins of behavioral inhibition in early childhood may be linked to a low threshold for arousal in forebrain limbic areas.

Affect↗

PubMed1998

Brief communication: a software solution for reducing startle eyeblink responses.

We examined the viability of a software-based spectral method for reducing acoustic startle eyeblink responses. Fifteen young adults were presented with a 95 dB burst of white noise for 50 ms while they viewed slides that varied in affective valence. The startle EMG responses were analyzed using a discrete Fourier transform software-based spectral method. A significant linear trend was found between slide valence and startle amplitude, replicating previous work. Subjects' startle responses became more augmented as the content of the slides became more unpleasant. The advantages of software-based solutions for reducing startle EMG responses are discussed.

Adult↗

PubMed1998

Acoustic startle electromyographic (EMG) activity indexed from an electroculographic (EOG) electrode placement: a methodological note.

Acoustic startle EMG responses were indexed from a traditional EOG electrode placement in 11 young adults while they viewed slides which varied in affective valence. We found, replicating earlier work that subjects' startle responses became more augmented as the content of the slides became more negative. The advantages of using an EOG electrode placement for measuring acoustic startle responses are discussed.

Acoustic Stimulation↗

PubMed1998

Music shifts frontal EEG in depressed adolescents.

Recent studies have found that positive affect is associated with greater relative left frontal EEG activation and negative affect is associated with greater relative right frontal EEG activation. Further, chronically depressed adults typically display stable right frontal EEG activation. The present study investigated the effects of music on mood state and right frontal EEG activation associated with chronic depression. Fourteen chronically depressed female adolescents listened to rock music for a 23-minute session. These adolescents were compared with a control sample of chronically depressed female adolescents who were simply asked to sit and relax their minds and their muscles for the same time period. EEG was recorded during baseline, music, and postmusic for three minutes each, and saliva samples were collected before and after the session to determine the effects of the music on stress hormone (cortisol) levels. No group differences or changes were noted for observed or reported mood state. However, cortisol levels decreased and relative right frontal activation was significantly attenuated during and after the music procedure. It was concluded that music had positive effects on the physiological and biochemical measures even though observed and self-reported mood did not change.

Adolescent↗

PubMed1998

Temperament and regulation of emotion in the first years of life.

Temperament is the tendency to express particular emotions with a certain intensity that is unique to each individual child. Although temperament seems to be biologically based, learning to regulate emotional expressions depends on caregiver input and socialization. Part of this process involves forming a trusting relationship with the infant so that he or she learns to rely on the parents to help "regulate" stressful or frustrating situations.

Child Development↗