Psychophysiological reactivity to stress in nail biters

Prevalence of probable sleep bruxism and associated factors in Brazilian schoolchildren

AIM

To determine the prevalence of probable sleep bruxism (PSB) and associated factors among schoolchildren.

DESIGN

This cross-sectional study was carried out with a representative sample of 440 schoolchildren. The children were submitted to a clinical oral examination for the evaluation of tooth wear and/or muscle discomfort. Parents/caregivers filled out a questionnaire with information related to characteristic sounds of sleep bruxism, sociodemographic factors, and the presence of harmful oral habits of children. The stress of the mothers was measured through the Lipp's Stress Symptoms Inventory for Adults (LSSI) instrument. The child's stress was measured through the Child Stress Scale (CSS). Data analysis included descriptive analysis and hierarchical Poisson regression (95% CI, P < 0.05).

RESULTS

The prevalence of PSB was 40.0% (n = 176). The final Poisson regression model showed that PSB was significantly more prevalent in children with a history of nail biting (PR: 1.50; 95% CI: 1.19-1.90; P = 0.001) and biting objects (PR: 1.30; 95% CI: 1.03-1.63; P = 0.025) and less prevalent among girls (PR: 0.78; 95% CI: 0.63-0.98; P = 0.033).

CONCLUSIONS

The prevalence of PSB in schoolchildren was high. Schoolchildren with a history of nail biting and biting objects had a higher prevalence of PSB.

Self-inflicted finger injury in individuals with spinal cord injury: an analysis of 5 cases

OBJECTIVE

To describe the occurrence of finger autophagia in 5 persons with traumatic spinal cord injury and to present a discussion of putative causes and potential treatments.

BACKGROUND

Minor self-mutilating actions, such as nail biting and hair pulling, are common in humans and usually benign. In some circumstances, these behaviors are associated with obsessive-compulsive personality traits. In humans, self-injurious biting behaviors are well described in the setting of mental retardation and psychosis and in persons with Lesch-Nyhan syndrome. Rare cases of human autophagia in persons with intact cognition have been reported, most commonly in the setting of acquired nervous system lesions. After spinal cord injury, it has been suggested that this behavior constitutes a human variant of animal autotomy and a response to neuropathic pain.

DESIGN

Case presentation narrative.

MAIN OUTCOME MEASURES

Photographic and radiological study, administration of Yale-Brown Obsessive-Compulsive Scale (YBOCS).

FINDINGS

In 5 patients with complete tetraplegia, pain in the hands was present in only one instance. The severity of autoamputation varied from minor to extreme. In all cases, damage was confined to analgesic body parts. In 3 cases, autophagia behavior was discovered in progress. Treatments included pharmacotherapy, counseling, and behavioral therapy, with mixed results. All patients were intelligent, willing to discuss their issues, and able to identify conditions of stress and isolation in their lives. Mild preinjury obsessive-compulsive behaviors, such as nail biting, were universal. On the YBOCS, only 1 patient scored in a range indicative of mild obsessive-compulsive symptomatology.

CONCLUSIONS

This group exhibited heterogeneous medical, social, and cultural characteristics. A link between pain and self-injurious behavior could not be demonstrated. This behavior may be viewed as an extreme variant of nail biting, with potential ominous complications. Treatment strategies have been employed with mixed results.

What is the function of nail biting: an analog assessment study

OBJECTIVE

To compare the frequency of nail biting in 4 settings (interventions) designed to elicit the functions of nail biting and to compare the results with a self-report questionnaire about the functions of nail biting.

DESIGN

Randomised allocation of participants to order of conditions.

SETTING

University Psychology Department.

SUBJECTS

Forty undergraduates who reported biting their nails.

INTERVENTIONS

Left alone (boredom), solving maths problems (frustration), reprimanded for nail biting (contingent attention), continuous conversation (noncontingent attention).

MAIN OUTCOME MEASURES

Number of times the undergraduates bit their nails.

RESULTS

Nail biting occurred most often in two conditions, boredom and frustration.

CONCLUSION

Nail biting in young adults occurs as a result of boredom or working on difficult problems, which may reflect a particular emotional state. It occurs least often when people are engaged in social interaction or when they are reprimanded for the behavior.

Psychodynamics of onychophagists

The authors offer three interpretations of onychophagia, a widespread but largely unstudied phenomenon. The first is phenomenological, and characterises onychophagia as a non-pathological behavioural symptom present in many pathologies and a distinct syndrome that is sometimes quite severe. The second is clinical, and indicates the convergent and divergent connections between onychophagia and the most frequent eating disorders. The third is psychodynamic, and suggests an interpretative hypothesis of onychophagia itself and the frequent sensation of trouble and refusal that it often provokes even in doctors and psychotherapists.