This study was performed to test the hypothesis that emotionally stressful states measured by the urinary catecholamines may affect the development of bruxism. Three hundred and fourteen children, boys and girls, aged 6-8 years were included in this study. Bruxism was recorded by a clinical examination and an interview. Positive evidence of this parafunction was defined as the presence of both historical and clinical indicators. Information concerning systemic and socio-economic factors was collected by a questionnaire. A 24-h urine sample was collected for each subject and analysed by the high performance liquid chromatography technique to assay the catecholamine content. Of the total of 273 children who had a complete 24-h urine sample, 167 were identified to be with and without positive evidence of bruxism. The logistic multiple-regression analysis was carried out to test whether the presence of bruxism was affected by the variables studied; 95% probability was used. The results showed that epinephrine and dopamine had a significant and strong association with bruxism. The data therefore provide support for the concept that emotional stress is a prominent factor in the development of bruxing behaviour.

An epidemiological study was conducted to investigate the relationship between craniomandibular dysfunction and oral parafunctions in 386 children aged 6-10 years with and without unpleasant life events. The results showed statistically significant correlations between grinding, clenching, lip/cheek biting and muscle tenderness or pain, and clicking in subjects without unpleasant life events. Also, significant correlations were found in the same group between these parafunctions and difficulties in opening wide and pain on movements. When the definitional symptoms of craniomandibular dysfunction were aggregated, the chi-square test revealed significant correlations between them and the same oral parafunctions. The correlations in subjects with unpleasant life events between grinding, clenching, lip/cheek biting and each sign and symptom of craniomandibular dysfunction were close to the significance level. No significant correlations were detected between the definitional symptoms and these parafunctions in this group. The present study suggests that in patients without unpleasant life events grinding, clenching, and lip/cheek biting cannot be considered 'necessary' but can be 'sufficient' cause for the development of craniomandibular dysfunction. In subjects with unpleasant life events the origin of signs/symptoms of the dysfunction can be attributed to muscle tension or to another unknown aetiological factor.

On the basis of these results, it can be suggested that parafunctional and some structural and psychological factors may increase the probability of the child developing the signs and symptoms of CMD.

Incidence of dentofacial injuries in children: a 2-year longitudinal study Vanderas AP, Papagiannoulis L. Incidence of dentofacial injuries in children: a 2-year longitudinal study. Endod Dent Traumatol 1999; 15: 235-238. 0 Munksgaard, 1999. Abstract -In this prospective study the incidence of dentofacial injuries in 199 children aged 8 to 10 years was analyzed. Dentofacial injuries were recorded by a questionnaire and a clinical examination. After the first examination, each subject was re-examined at yearly intervals over a period of 2 years. Incidence rates were calculated in percentages and the chi-square was applied to test statistical differences. The 95% probability level was used. Results showed that the overall incidence of dentofacial injuries was 45.2%. The percentages for boys and girls were 28.6 and 16.6 respectively. The chi-square test showed significant gender differences, while differences by age were not significant. The highest incidence was recorded for dental injury followed by facial injury, historical evidence of injury and dental and facial injury.Dentofacial injury is of particular interest in the field of dentistry. Dental injuries need long-term follow-up because of the risk of possible complications (1-3), while facial or dentofacial injuries may cause craniomandibular dysfunction (4) and/or esthetic problems due to scarring. Epidemiologic studies have focused on the investigation of the prevalence or incidence of dental injury (5). The incidence of dentofacial injury in children, however, has not been investigated.The purpose of this prospective study was to record the incidence of dentofacial injury in children aged 8 to 10 years. Materials and methods Study populationThe subjects selected for this study were participating in a cross-sectional investigation based on a sample of 221 children, 11 3 boys and 108 girls, aged 8 to 10 years. After the first examination, each subject was re-examined at 1-year intervals for a period of 2 years. At the first and second year 205 and 199 children were re-examined respectively. The difference in the number of subjects between the examinations was due to the fact that 1 1 children had moved

A high caries index increases the risk of developing caries in the sound proximal surfaces of posterior primary teeth and causes faster progression of the external half of the enamel lesions in the first permanent molars and posterior primary teeth.