Examining caries aetiology in adolescence with structural equation modelling.

OBJECTIVES: This analysis examines the aetiology of caries development in adolescents using structural equation modelling to identify behavioural mediators of the relationship between socioeconomic status (SES) and caries incidence, and to investigate the role of sex on caries-preventive behaviour and caries. METHODS: This analysis was based on data from the Iowa Fluoride Study, a longitudinal study of a birth cohort. We hypothesized that socioeconomic status earlier in life has a direct effect on caries development and an indirect effect from improved behavioural variables-dental visit attendance, toothbrushing frequency and percentage of beverage intake consisting of sugar-sweetened beverages-and that sex also plays a role in behavioural variables, as well as caries. A structural equation model was developed based on these hypotheses, and direct and indirect standardized path coefficients were calculated, as well as their standard errors. RESULTS: Based on our proposed model, SES at birth significantly influences SES during adolescence, but not adolescent behaviours. The effect of SES during adolescence on caries in the permanent dentition is mediated by adolescent behaviours. Female participants have worse caries than male participants, despite lower self-reported percentages of sugar-sweetened beverage intake and more frequent brushing and dental attendance. CONCLUSIONS: This analysis models the relationships among known causal factors for caries and suggests that the role of SES in caries may not be as important as previously thought and different behaviours that affect oral health between males and females as well as differences in caries between the sexes could begin during adolescence. These findings could help improve caries prevention programmes for adolescents.

Dosimetry of small radiation fields for 10-MV x rays.

Dosimetry for 10-MV x rays has been extended to radiation fields smaller than 4 X 4 cm which may be suitable for radiation therapy of small lesions, e.g., intracranial tumors, benign or malignant. Special consideration in this study was given to (i) the variation of dose with field size (collimator and phantom scatter), (ii) the central axis percentage depth doses, and (iii) the moving-beam therapy dose distribution. We conclude that simple dosimetric techniques can provide adequate physics background for stereotaxic radiosurgery with small radiation fields and high-energy x rays.

Intracranial abscesses secondary to ear and paranasal sinuses infections.

The death rate of brain abscesses in a recently reported series is high, ranging from 36% to 50% of all cases. This paper reports experiences with ten cases of intracranial abscesses secondary to ear and sinus infections. Six of these abscesses are secondary to otitic infections with three of them located in the cerebellum. Two of the cerebellar abscesses are surgically drained through the temporal bone by the otologic surgeon, with close neurosurgical cooperation. Computerized axial tomography has revolutionized the treatment of intracranial abscesses optimizing the timing for medical and surgical management.

Assessment of a pilot child playground injury prevention project in New York State.

Following a child playground equipment injury prevention project conducted in New York State in 1977, there was a 42 per cent reduction in playground equipment hazards, and a 22.4 per cent reduction in playground related injuries treated in the two largest hospitals of one of the program sites. Knowledge about unsafe playground practices and equipment hazards improved after the workshops for playground personnel. This approach to injury prevention deserves further study.