The relationship between dental overbite and eustachian tube dysfunction.

OBJECTIVE: The purpose of this study was to investigate the association between deep dental overbite and eustachian tube dysfunction (ETD). DESIGN: Case-control study. SETTING: Tertiary care pediatric otolaryngology outpatient clinic at the Children's Hospital, Boston, Massachusetts. PATIENTS: 105 patients between the ages of 2 and 6 years. STUDY MEASUREMENTS: Dental overbite, overjet, and occlusal relationships were measured by an observer who was unaware of ETD status. ETD was defined as having ventilation tubes in place or having the recommendation for ventilation tube placement by an attending pediatric otolaryngologist. In addition, demographic information and medical and social histories were prospectively recorded. RESULTS: In a multivariate logistic regression model, children with deep bites were 2.8 times more likely to have ETD than those without deep bites (P = .03). Other independent risk factors for ETD identified in this model were family history of otitis media (OM) and age less than 3 years. CONCLUSIONS: Children with deep dental overbites are at a significantly increased risk for developing ETD.

Studies of lead exposure and the developing central nervous system: a reply to Kaufman.

Kaufman's critique of the lead-cognition hypothesis is a reiteration of well worn and weary claims raised many times in the past, primarily by spokespersons for the lead industry. They have been fully rebutted in the literature. The essence of these claims is that those studies showing an association between lead and IQ are flawed by uncontrolled confounding, multiple comparisons, and errors in measurement. Any effect of lead, Kaufman asserts, if present, is small. This response examines each of these issues and shows that they lack substance. Lead's negative impact on IQ persists in most modern studies after confounding has been controlled in many different statistical models. At least three metaanalyses have confirmed an effect of lead at low dose. Animal studies in which lead is given systematically, and the issue of confounding thereby avoided, demonstrate an unequivocal lead effect at similar doses to the human studies. The criticism of multiple comparisons similarly does not withstand examination. Measurement errors are nonsystematic and nondifferential. They are, therefore, null biasing. The actual size of the lead effect has been shown to be substantial, and to be found most prominently at the ends of the distribution. Kaufman says that lead requires study of diverse dimensions of intellect, but he restricts his scope to a sample of studies of lead and IQ, ignoring recent high quality studies that show a clear lead effect, and in those studies that he critiques he ignores data that contradict his position. His article adds nothing to the dialogue on lead neurotoxicity.

The influence of medical history on restorative procedure failure rates following dental rehabilitation.

PURPOSE: This study evaluated the association between patient medical history and the outcomes of restorative procedures performed under general anesthesia. METHODS: The dental records of patients who had dental rehabilitation under general anesthesia at Children's Hospital in Boston (1990-1992) and Children's National Medical Center in Washington, DC (1994-1998) were examined. Data regarding restorative outcomes and the association between patient medical history and restorative failures were assessed using chi-square tests with correction for continuity. T-tests were performed on parametric data. RESULTS: Significantly higher stainless steel crown failure rates were found in young patients diagnosed with developmental disabilities when compared to patients without such disabilities (p<0.025, x2 = 5.50). However, there was no difference in the failure rates of SSCs in young patients with significant medical histories compared to patients without significant medical histories. Regarding amalgam and composite restorations, there were no differences in failure rates among patients with and without significant medical histories, including developmental disabilities. CONCLUSIONS: SSC failures were higher in young children with developmental disabilities compared to children without these disabilities.

The removal of lead from gasoline: historical and personal reflections.

Tetraethyllead (TEL) was first fabricated for use in gasoline in 1923. Shortly after manufacture began, workers at all three plants began to become floridly psychotic and die. A moratorium on TEL production was put into place, but was lifted in 1926. Between 1926 and 1965, the prevailing consensus was that lead toxicity occurred only at high levels of exposure and that lead in the atmosphere was harmless. Most of the data on lead toxicity issued from a single source, the Kettering Laboratory in Cincinnati. In 1959, the first warnings of adverse health effects of lead at silent doses were raised by Clair Patterson, a geochemist. In hearings before the Senate Committee on Public Works, Senator Edward Muskie raised the question of adverse health effects from airborne lead. As new data accumulated on health effects of lead at lower doses, the movement to remove lead from gasoline gained momentum, and the Environmental Protection Agency examined the question. The removal of lead would take place over the next 25 years, and its accomplishment would require a severe change in the federal stance regarding its hazard. This article details the interaction of various forces, industrial, regulatory, judicial, public health, and public interest, that were engaged in this contest and estimates the value of this step.

Reports of pain by children undergoing rapid palatal expansion.

PURPOSE: This study described and quantified the prevalence, timing, and intensity of pain during the expansion phase of rapid palatal expansion (RPE) in children and investigated whether pain was related to age, sex, or rate of expansion. METHODS: Ninety-seven children, 38 males and 59 females, between the ages of 5 to 13 years (median 7.7 years) undergoing RPE procedures with the Hyrax, Dentaurum, Newtown, PA, appliance were surveyed. The appliance was expanded with either one or two turns (1/4 mm/turn) per day based on the provider's preference. The child's pain response was measured no more than 5 minutes after each turn for the entire period of expansion using both the Facial Pain Scale and the Color Analog Scale. RESULTS: Ninety-eight percent of the children reported at least some pain during RPE. The highest levels of pain were reported during the first 10 turns with the greatest intensity during the first 6 turns and a steadily decreasing amount of pain thereafter. Pain medication was taken after 7% of the expansion turns in the study with the majority of children taking the medication during the first 6 turns. Forty-eight percent of the children took pain medication at least once during the expansion phase of RPE. There was no difference in either reported pain or use of pain medication based on age, sex, or stage of dentition. During the first 10 turns, children whose rate of expansion was two turns/day were more likely to report pain and take pain medication than children whose rate of expansion was one turn/day, thereafter there were no differences. CONCLUSIONS: The vast majority of children undergoing the active phase of rapid palatal expansion with a Hyrax appliance report pain. The pain generally occurs during the initial phase of expansion and diminishes thereafter, with two turns/day resulting in reports of pain greater than those expanding only once/day.

Bone lead levels and language processing performance.

The relation between bone lead absorption and language processing abilities in 156 randomly selected 11- to 14-year-old boys who were asymptomatic for lead toxicity is examined. Tibial lead concentrations were measured by X-ray fluorescence spectroscopy. The language processing outcome variables consisted of the least and most difficult subtests from the Nonword Repetition Task, Competing Language Processing Task, and the Revised Token Test. Participants were classified by quartiles according to bone lead concentrations, and analysis of variance and analysis of covariance measured the impact on language processing scores. Results showed that children in the highest bone lead quartile displayed decreased language processing performance on the most difficult language processing tasks but not on the easier tasks.

Periodontitis in the child and adolescent.

Early onset periodontitis (EOP) which affects individuals thirty-five and younger is characterized by a rapid rate of bone loss and disease progression with defects in host response and a specific etiological microbial flora. Within this classification, there are three subsets of the disease: prepubertal periodontitis, juvenile periodontitis, and rapidly progressive periodontitis. The characteristics of each disease are described along with illustrative cases that will help clinicians diagnose EOP in their patients. Currently prescribed treatment modalities and guidelines from the literature are also discussed in this paper. EOP may represent a complex set of diseases that are likely to be reclassified as further advances in microbiological and genetic research are made. Clinicians should be aware of such changes in order to diagnose, treat, and refer their patients for comprehensive care.

Childhood lead poisoning: the promise and abandonment of primary prevention.

In 1991, the Public Health Service published the Strategic Plan for the Elimination of Childhood Lead Poisoning. This document marked a fundamental shift in federal policy from finding and treating lead-poisoned children to authentic primary prevention. It spelled out a 15-year strategy to achieve this goal and provided a cost-benefit analysis showing that the monetized benefits far exceeded the costs of abatement. A strong national effort to eliminate the disease developed. Now, 7 years after publication of the plan, primary prevention of lead exposure has been abandoned. This article examines the role of some prevailing attitudes and institutions in derailing the effort. Some institutions--the lead industry, real estate interests, and insurance interests--behaved as anticipated. Others, including private pediatricians, the American Academy of Pediatrics, some federal agencies, and a public interest group ostensibly dedicated to eliminating lead poisoning, also played an unexpected part in derailing the plan.

Alveolar bone height of primary and first permanent molars in healthy seven- to nine-year-old children.

The purpose of the study was to establish baseline values of the alveolar bone height of the primary molars and first permanent molars in sample of healthy U.S. seven- to nine-year-old children. Direct measurements of the distance from the cementoenamel junction (CEJ) to the alveolar crest (AC) on 223 pairs of bitewing radiographs from 223 subjects were made using a digimatic caliper under standardized conditions. The distance from the CEJ to the AC had medians from 0.58 mm to 1.39 mm (range 0.0 to 4.44 mm) for the primary molars and from 0.00 mm to 0.64 mm (range -1.35 to 2.15 mm) for the mesial aspect of the permanent molars. There were no statistically significant differences in the distance from CEJ to AC between teeth on the right and left sides of the mouth. The distances from CEJ to AC were always greater in the maxilla than in the mandible for similar primary molar sites, but only true for the mesial aspect of the permanent first molar at age nine. As a tooth is positioned more anteriorly in the mouth, the distance from CEJ to AC was greater. On the whole, males had greater distances than females and eight-year-olds had larger distances than seven- or nine-year-olds. Differences were observed in the measured distances for the different age and sex-groups and may be attributable to variations in eruption and exfoliation patterns. The distance was significantly greater in areas of interproximal restorations and open contacts, and there was a tendency for the distances to be greater in areas of interproximal caries.

Clamped in a straitjacket: the insertion of lead into gasoline.

In 1925, shortly after production of tetraethyl lead began, an outbreak of psychosis occurred in all three operating plants, and a number of workers died in acute mania. A temporary moratorium on the production of tetraethyl lead was imposed, and the Public Health Service convened a meeting of scientists, public health officials, and industrial representatives to investigate the safety of the product. This paper reviews the steps leading to the insertion of lead into gasoline, the response of industry to the tragic poisoning, the actions of the public health authorities to investigate the episode, and the forces that resulted in the restoration of the additive to gasoline.

Bone lead levels and delinquent behavior.

OBJECTIVE: To evaluate the association between body lead burden and social adjustment. DESIGN: Retrospective cohort study. SETTING: Public school community. PARTICIPANTS: From a population of 850 boys in the first grade at public schools, 503 were selected on the basis of a risk scale for antisocial behavior. All of the 850 boys who scored in the upper 30th percentile of the distribution on a self-reported antisocial behavior scale were matched with an equal number drawn by lot from the lower 70% of the distribution. From this sample, 301 students accepted the invitation to participate. EXPOSURE MEASURE: K x-ray fluorescence spectroscopy of tibia at subjects' age of 12 years. MAIN OUTCOME MEASURES: Child Behavior Checklist (CBCL), teachers' and parents' reports, and subjects' self-report of antisocial behavior and delinquency at 7 and 11 years of age. RESULTS: Subjects, teachers, and parents were blind to the bone lead measurements. At 7 years of age, borderline associations between teachers' aggression, delinquency, and externalizing scores and lead levels were observed after adjustment for covariates. At 11 years of age, parents reported a significant lead-related association with the following CBCL cluster scores: somatic complaints and delinquent, aggressive, internalizing, and externalizing behavior. Teachers reported significant associations of lead with somatic complaints, anxious/depressed behavior, social problems, attention problems, and delinquent, aggressive, internalizing, and externalizing behavior. High-lead subjects reported higher scores in subjects' self-reports of delinquency at 11 years. High-lead subjects were more likely to obtain worse scores on all items of the CBCL during the 4-year period of observation. High bone lead levels were associated with an increased risk of exceeding the clinical score (T > 70) for attention, aggression, and delinquency. CONCLUSION: Lead exposure is associated with increased risk for antisocial and delinquent behavior, and the effect follows a developmental course.

Effects of blood lead levels on cognitive function of older women.

Elevated blood lead concentrations are known to have detrimental effects on neuropsychological function in both children and occupational cohorts of men and women. Although it is generally accepted that lead exposure at low levels is more dangerous for infants and children than for adults, the issue of the lowest level of exposure at which lead causes deleterious health effects in adults is yet to be solved. There is no available data on the role of lead exposure in cognitive dysfunction in nonoccupational cohorts of older persons. In the current study, we examined the cross-sectional relationship between blood lead levels and a variety of measures of neuropsychological function in a large cohort of elderly women recruited at both urban and rural sites. This study of elderly women demonstrates that blood lead levels as low as 8 micrograms/dl were significantly associated with poorer cognitive function as measured by certain neuropsychological tests. Even a slight decrement in cognition would have a large public health impact due to the large number of elderly at risk.

Conscious sedation of pediatric dental patients using chloral hydrate, hydroxyzine, and nitrous oxide--a retrospective study of 382 sedations.

This retrospective study assessed the effectiveness and safety of chloral hydrate (55 mg/kg), hydroxyzine (1 mg/kg), and nitrous oxide in the sedation of 336 uncooperative pediatric dental patients over 382 sedation sessions, and identified variables associated with effectiveness including: sex, weight, age, and preoperative behavior of the patient; route and combinations of the sedative drugs; and sex of the operating and monitoring dentists. The operating and monitoring dentists rated the sedation session as either effective or ineffective and also as either heavy, moderate, light or poor. The mean age of the children was 2.6 years and mean weight was 14.1 kg. Seventy-four percent of the sedation sessions were deemed effective. Boys had more effective sessions (80.6%) than girls (65.1%) (P = 0.001). Also, the percentage of sedations rated as effective increased as the preoperative behavior was more positively rated (P = 0.001). Oral regimen of chloral hydrate alone or in combination with oral hydroxyzine was more effective (75.5%) than rectal administration of chloral hydrate alone (65.7%) (P = 0.09). There was no significant difference in effectiveness when chloral hydrate was administered orally alone or in combination with oral hydroxyzine. Sedation sessions rated effective had longer operative times, included more sextants of treatment, were more likely to include restorative treatment, and were less likely to include extractions than the ineffective sedations. Vomiting was the only complication reported, occurring in 8.1% of the sedations. Vomiting did not vary significantly with either route of administration or inclusion of hydroxyzine in the oral regimen. Pulse rates were significantly higher for children in the ineffective sedation sessions. This sedative drug regimen was deemed safe and effective for treating young and uncooperative pediatric dental patients.

Enamel hypoplasia, bilateral cataracts, and aqueductal stenosis: a new syndrome?

We report on a 12-year-old girl who presented with generalized enamel hypoplasia, cataracts, and enlargement of the cerebral ventricles secondary to aqueductal stenosis. Previously described syndromes of enamel defects with or without cataracts were excluded on the basis of clinical criteria and appearance of the dentition. Metabolic conditions which could have caused cataracts were excluded clinically and by biochemical tests. The combination of signs in this patient may represent a new syndrome.

Effect of familial hypophosphatemic rickets on dental development: a controlled, longitudinal study.

Familial or X-linked hypophosphatemic rickets (XLHR) is the most common type of rickets in developed countries today. While the dental manifestations of rickets are well reported, there is little information regarding its relationship to dental development and other dental anomalies. This investigation studied the rate of dental development and associated dental anomalies in 19 XLHR subjects compared with 38 race-, age-, and sex-matched control children. The results showed that in both XLHR and control children, no significant differences existed in dental age compared with the respective chronological age, indicating that rickets did not affect the rate of dental development. Longitudinal growth curves of seven XLHR and matched control children substantiated that relationships of dental to chronological ages were comparable in both groups. Male XLHR subjects showed significantly increased tendency for dental taurodontism with mean Crown-Body (CB):Root (R) ratio of 1.1 compared with 1.0 in females and 0.8 in controls (P < 0.02). Male XLHR children also showed significantly increased prevalence (50%) of ectopic permanent canines compared with control children (8%, P < 0.01).

Behavioral toxicology.

The new fields of behavioral toxicology and behavioral teratology investigate the outcome of specific toxic exposures in humans and animals on learning, memory, and behavioral characteristics. Three important classes of behavioral neurotoxicants are metals, solvents, and pesticides. The clearest data on the deleterious effects of prenatal exposure to toxicants comes from the study of two metals, lead and mercury, and from epidemiological investigations of the effects of alcohol taken during pregnancy. Less complete data are available for two other groups of agents, solvents and pesticides. What we do know about their effects on the fetal brain is convincing enough to make us demand caution in their distribution.