The effect of Frankel II and modified twin block appliances on the 'C'-axis: the growth vector of the dentomaxillary complex

The recently determined 'C'-axis, the growth vector of the dentomaxillary complex, permits an evaluation of any meaningful growth changes thereto by the Frankel II and modified Twin Block functional appliances. Retardation of the velocity of change (mm/year) in length of the 'C'-axis did not occur. The angular relationship of the 'C'-axis to Sella-Nasion (theta) and to the palatal plane (alpha) were not altered in a clinically significant way. Favorable changes observed in the correction of Class II malocclusions are likely because of dentoalveolar alterations buttressed by favorable mandibular growth.     

The benefit of the operating microscope for access cavity preparation by undergraduate students

Although studies show the operating microscope (OM) provides benefits for endodontists, the benefit to undergraduates has not been evaluated as completely as for specialists. The purpose of this study was to determine whether using the OM would improve students' performance in endodontic access cavity preparation and canal identification. Thirty-six dental students prepared access cavities and located canals in extracted maxillary molars, before and after training, which varied according to group. The standard group received a lecture and practice in preparation of access cavities. The microscope group received identical instruction using the OM. The control group received lectures only. All groups received equal content and instruction time (2 hr 20 min). Faculty graded preparations according to a multidimensional 5-point rating scale. Using the OM, the microscope group improved significantly in access cavity preparation (p <0.05) and significantly outperformed both standard and control groups in accuracy of identifying canals (p <0.05).     

Retention of a fluoride-releasing sealant compared with its non-fluoride analogue: interim results of a clinical study after an average of eight months

OBJECTIVE: To compare the retention of a fluoride-releasing sealant with its non-fluoride analogue in a school-based sealant program. METHODOLOGY: A total of 294, second- and third-grade students, in two schools, were divided within school into two sealant groups; those with Delton and those with its fluoride analogue, Delton Plus. Subjects had one or more pit-and-fissure sites on occlusal or buccal-lingual surfaces of six-year molars suitable for sealant application. Two examiners identified sealable sites as those that were sound or had incipient decay, and were sufficiently erupted for sealant application. Dental students sealed identified sites under faculty supervision. The mean follow-up time between sealant placement and interim exams was eight months in both groups. RESULTS: A total of 256 subjects were present for interim exams. Percentages of subjects fully retaining sealants on none of the occlusal sites in the F and non-F groups were 7.0% and 10.8%, and for buccal-lingual sites, 54.6% and 57.0%, respectively. The mean subjectwise proportions of fully retained sealants on occlusal sites were 70.8% for F, and 63.2% for non-F groups; corresponding mean scores for buccal-lingual sites were 28.0% for F, and 27.7% for non-F groups. None of the results of retention by percentage of subjects (Chi-square test) or by mean percent of sites per subject (ANOVA test) was statistically significant at the alpha level of 0.05. CONCLUSION: Interim results comparing fluoride and non-fluoride sealants suggest meaningful and comparable levels of full retention for occlusal sites, whereas for buccal-lingual sites, full retention was poor for both types of sealants. Partially retained sealants, when included in the data analyses, offered mixed interpretation as to outcome of sealant "success" or "failure".     

An evidence-based review of important issues concerning neonatal hyperbilirubinemia

This article is adapted from a published evidence report concerning neonatal hyperbilirubinemia with an added section on the risk of blood exchange transfusion (BET). Based on a summary of multiple case reports that spanned more than 30 years, we conclude that kernicterus, although infrequent, has at least 10% mortality and at least 70% long-term morbidity. It is evident that the preponderance of kernicterus cases occurred in infants with a bilirubin level higher than 20 mg/dL. Given the diversity of conclusions on the relationship between peak bilirubin levels and behavioral and neurodevelopmental outcomes, it is apparent that the use of a single total serum bilirubin level to predict long-term outcomes is inadequate and will lead to conflicting results. Evidence for efficacy of treatments for neonatal hyperbilirubinemia was limited. Overall, the 4 qualifying studies showed that phototherapy had an absolute risk-reduction rate of 10% to 17% for prevention of serum bilirubin levels higher than 20 mg/dL in healthy infants with jaundice. There is no evidence to suggest that phototherapy for neonatal hyperbilirubinemia has any long-term adverse neurodevelopmental effects. Transcutaneous measurements of bilirubin have a linear correlation to total serum bilirubin and may be useful as screening devices to detect clinically significant jaundice and decrease the need for serum bilirubin determinations. Based on our review of the risks associated with BETs from 15 studies consisting mainly of infants born before 1970, we conclude that the mortality within 6 hours of BET ranged from 3 per 1000 to 4 per 1000 exchanged infants who were term and without serious hemolytic diseases. Regardless of the definitions and rates of BET-associated morbidity and the various pre-exchange clinical states of the exchanged infants, in many cases the morbidity was minor (eg, postexchange anemia). Based on the results from the most recent study to report BET morbidity, the overall risk of permanent sequelae in 25 sick infants who survived BET was from 5% to 10%.     

Pharmacokinetics of enfuvirtide in pediatric human immunodeficiency virus 1-infected patients receiving combination therapy

BACKGROUND: Enfuvirtide is the first of a new class of antiretroviral agents, the fusion inhibitors. OBJECTIVES: The primary objective of this analysis was to evaluate the pharmacokinetics of 2.0 mg/kg enfuvirtide in human immunodeficiency virus 1 (HIV-1)-infected children and adolescents when administered in combination with at least 3 other antiretrovirals. METHODS: Twenty-five HIV-1-infected pediatric patients (5-16 years of age) enrolled in an ongoing phase I/II study were included in this analysis. Patients received enfuvirtide 2.0 mg/kg sc twice daily (bid) for at least 7 days. Blood samples were collected on day 7, and plasma concentrations of enfuvirtide and its metabolite were measured by a validated liquid chromatography-tandem mass spectrometry method. Pharmacokinetics measures [Cmax, tmax, Ctrough, and area under the concentration time curve time 0 to 12 hours (AUC12 hours)] were calculated from plasma concentration-time data by standard noncompartmental methods. RESULTS: There was no significant difference between children and adolescents for enfuvirtide Cmax (6.43 versus 5.88 microg/mL), Ctrough (2.87 versus 2.98 microg/mL) and AUC12 hours (56.1 versus 52.7 hours . microg/mL). Similarly no significant differences were found when the pharmacokinetic measures were compared based on sexual maturity stages. A post hoc regression analysis based on AUC12 hours showed that body weight-adjusted dosing of enfuvirtide provides drug exposure that is independent of age group, body weight and body surface area. CONCLUSIONS: Body weight-adjusted dosing of enfuvirtide, at a dose of 2.0 mg/kg sc bid, in HIV-1-infected pediatric patients at least 5 years of age, provides drug exposure comparable with that previously observed in HIV-1-infected adults after 90 mg sc bid dosing. Drug exposure in children and adolescents is independent of age group, body weight, body surface area and sexual maturity stage.     

Analysis of recurrences in 322 Tis, T1, or T2 glottic carcinomas treated by carbon dioxide laser

An endoscopic approach to early glottic carcinoma is considered a sound treatment for both previously untreated lesions and selected recurrent lesions. Between January 1988 and December 2000, we treated 322 patients by CO2 laser at a single institution; 37 had Tis, 191 T1a, 55 T1b, and 39 T2 lesions (mean follow-up, 77 months; range, 6 to 180 months). Kaplan-Meier curves showed a 5-year overall survival rate of 88%, a determinate survival rate of 99%, a disease-free survival rate of 81%, a rate of ultimate local control with laser alone of 91%, and a laryngeal preservation rate of 97%. Univariate and multivariate analysis showed that the only factor that statistically affected endoscopic control was lateral extension of the tumor with involvement of the bottom of the ventricle (hazard risk ratio, 4.0; 95% confidence interval, 1.71 to 9.35). The 58 recurrences were classified according to their location compared with the site of the primary tumor as follows: 14 in the same area (group A), 27 in adjacent subsites with superficial spreading or multifocal distribution (group B), and 17 in adjacent sites by submucosal diffusion to the visceral spaces, cartilaginous framework, or extralaryngeal tissues (group C). For each group, we analyzed the rate of patients who underwent salvage by endoscopic or open neck procedures and the rate of laryngeal preservation. Recurrences in groups A and B were endoscopically treated in 86% and 74% of cases, respectively. By contrast, in group C no patient was endoscopically cured, and there was a low laryngeal preservation rate (47%). The pathways of spread in recurrent carcinoma are therefore the single most important factor in predicting its endoscopic curability.