Epidemiology of necrotizing ulcerative gingival lesions in adolescents

OBJECTIVE AND BACKGROUND

Relatively little is known about the epidemiology of necrotizing ulcerative gingival lesions (NUG) in adolescent populations. Most studies have comprised special target groups, such as military recruits, HIV patients, or severely malnourished subjects.

METHODS

A multistage random cluster sampling scheme was used to obtain a sample of 9203 students aged 12-21 years from 98 of a total of 618 high schools in Santiago, Chile. Students were given a clinical oral examination and questionnaire information was obtained on smoking and oral hygiene habits, dental attendance patterns, and diabetic status. The diagnostic criteria for NUG were the presence of necrosis and ulceration of at least one interproximal papillae.

RESULTS

The estimated prevalence of NUG was 6.7% (95% CI = [6.2; 7.3]). A multivariable logistic regression analysis showed that last seeing a dentist more than 1 year ago (OR = 1.60), or never (OR = 1.93), and reporting diabetes (OR = 2.12) showed a significant positive association with the presence of NUG; whereas neither gender nor smoking were important predictors. Students aged 18-21 years were more, albeit statistically insignificantly, likely to have NUG than were younger students (OR = 1.40).

CONCLUSIONS

Our observation that reporting to be diabetic was positively associated with the presence of NUG is interesting, as diabetes has never been addressed as a possible risk factor. As the association between diabetes and periodontitis in adults is thought to relate to impaired function of neutrophils, microangiopathy, and impaired wound healing this finding suggests a significant role of the host response also for the occurrence of NUG.

Epidemiology of clinical attachment loss in adolescents

BACKGROUND

Relatively little is known about the prevalence, severity, and determinants of clinical attachment loss among adolescents.

METHODS

A multi-stage random sampling procedure was used to obtain a sample of 9,203 high school students aged 12 to 21 years from the Province of Santiago, Chile. All but 41 students were examined for clinical attachment loss in 6 sites of first and second molars and incisors. The students were interviewed with respect to tooth brushing habits, smoking habits, dental visits, and diabetic status. Logistic regression analyses were used to assess the relative strength of the associations between age, gender, smoking, tooth brushing habits, dental attendance patterns, diabetic status, and governmental school support and the occurrence of clinical attachment loss.

RESULTS

Overall, clinical attachment loss > or = 1 mm was seen in 69.2% of the students; > or = 2 mm in 16% of the students; and > or = 3 mm in 4.5%. The distribution of clinical attachment loss was markedly skewed, but followed a continuum of disease severity. Logistic regression analyses showed that attachment loss was associated with higher age, female gender, infrequent tooth brushing, infrequent dental visits, and attending a high school receiving governmental support.

CONCLUSIONS

No sharp distinction exists between periodontal health and disease among Chilean adolescents. Higher age, poor oral hygiene, and a lower socioeconomic background play a role in the occurrence of clinical attachment loss.

The role of discriminant analysis in the refinement of customer satisfaction assessment

OBJECTIVE

To test discriminant analysis as a method of turning the information of a routine customer satisfaction survey (CSS) into a more accurate decision-making tool.

METHODS

A 7-question, 10-multiple choice, self-applied questionnaire was used to study a sample of patients seen in two outpatient care units in Valparaíso, Chile, one of primary care (n=100) and the other of secondary care (n=249). Two cutting points were considered in the dependent variable (final satisfaction score): satisfied versus unsatisfied, and very satisfied versus all others. Results were compared with empirical measures (proportion of satisfied individuals, proportion of unsatisfied individuals and size of the median).

RESULTS

The response rate was very high, over 97.0% in both units. A new variable, medical attention, was revealed, as explaining satisfaction at the primary care unit. The proportion of the total variability explained by the model was very high (over 99.4%) in both units, when comparing satisfied with unsatisfied customers. In the analysis of very satisfied versus all other customers, significant relationship was identified only in the case of the primary care unit, which explained a small proportion of the variability (41.9%).

CONCLUSIONS

Discriminant analysis identified relationships not revealed by the previous analysis. It provided information about the proportion of the variability explained by the model. It identified non-significant relationships suggested by empirical analysis (e.g. the case of the relation very satisfied versus others in the secondary care unit). It measured the contribution of each independent variable to the explanation of the variation of the dependent one.

Comparative biochemistry of a cytosolic artiodactyl glycosidase

Artiodactyls possess abundant neutral glycosidase activity in liver, kidney and intestine. This enzyme is cytosolic and displays a more neutral pH optimum, more acidic isoelectric point and broader substrate range than the corresponding acidic beta-galactosidases. The neutral glycosidases were more thermolabile than the respective acidic beta-galactosidases and displayed a relative molecular mass approximating 60 kDa. This isozyme appeared to be a minor species in both rat and dog liver. The porcine enzyme was studied in more detail. Porcine neutral glycosidase activity was detected in 45-day gestational fetuses in both liver and kidney but not brain. Fetal kidney activities were about half those observed in adult kidney extracts. Porcine neutral glycosidase was immunologically distinct from acidic beta-galactosidase and was immunologically similar to the corresponding isozymes from deer, ovine and bovine liver. Porcine neutral glycosidase was moderately inhibited by D-galactonic acid gamma-lactone and strongly inhibited by D-gluconic acid delta-lactone; however, acidic beta-galactosidase was not inhibited by the delta-lactone. Inhibition by the gamma-lactone was competitive for both enzymes. 4-Methylumbelliferyl-beta-D-galactoside,-glucoside and -xyloside competed for the same active site. A polymorphism for fast- and slow-migrating isozymes of porcine neutral glycosidase was observed, which appeared to be under genetic control.