Sagittal plane walking biomechanics in individuals with knee osteoarthritis after quadriceps strengthening.

OBJECTIVE: To compare sagittal walking gait biomechanics between participants with knee osteoarthritis (KOA) who increased quadriceps strength following a lower-extremity strengthening intervention (responders) and those who did not increase strength following the same strengthening protocol (non-responders) both at baseline and following the lower extremity strengthening protocol. DESIGN: Fifty-three participants with radiographic KOA (47% female, 62.3 ± 7.1 years, BMI = 28.5 ± 3.9 kg/m2) were enrolled in 10 sessions of lower extremity strengthening over a 28-day period. Maximum isometric quadriceps strength and walking gait biomechanics were collected on the involved limb at baseline and 4-weeks following the strengthening intervention. Responders were classified as individuals who increased quadriceps strength greater than the upper limit of the 95% confidence interval (CI) for the minimal detectable change (MDC) in quadriceps strength (29 Nm) determined in a previous study. 2 × 2 functional analyses of variance were used to evaluate the effects of group (responders and non-responders) and time (baseline and 4-weeks) on time-normalized waveforms for knee flexion angle (KFA), vertical ground reaction force (vGRF), and internal knee extension moment (KEM). RESULTS: A significant group x time interaction for KFA demonstrated greater KFA in the first half of stance at baseline and greater knee extension in the second half of stance at 4-weeks in responders compared to non-responders. There was no significant group x time interaction for vGRF or internal KEM. CONCLUSIONS: Quadriceps strengthening may be used to stimulate small changes in KFA in individuals with KOA.

Can the gastrointestinal microbiota be modulated by dietary fibre to treat obesity?

Recent research suggests that the human gastrointestinal microbiota is greatly involved in yielding, storing and expending energy from the diet; therefore, it may be a further factor in linking diet to obesity. The gut microbial composition is affected by diet throughout the human lifespan, and is highly dynamic and efficient in response to dietary alterations in particular to dietary fibre intake. Short-chained fatty acids (SCFA) are the bi-product of fibre fermentation and have both obesogenic and anti-obesogenic properties. The production of specific forms of SCFAs depends on the microbes available in the gut and the type of fibre ingested. The gut microbiome associated with healthy lean individuals has a higher microbial biodiversity and a greater Bacteroidete to Firmicute ratio compared to the obese individuals associated with microbiome. These gut microbial associations are similar to those seen in individuals with high and low dietary fibre intakes, respectively. Metabolites generated by Bacteroidetes and Firmicutes include the three main SCFA related to obesity, namely butyrate, acetate and propionate. However, neither Bacteroidetes nor Firmicutes is purely causative or purely preventative of obesity. More research is crucial in linking the various types of fibre with particular SCFA production and the microbiome it promotes before suggesting that dietary fibre modulation of the gut microbiome can treat obesity. However, the long-term dietary trend plays the principal role in assembling the diversity and abundance of gut microbes; thus, a sustained diet high in fibre may help prevent obesity by promoting a microbiome associated with a lean phenotype.

Genetic parameters for lamb birth weight, survival and death risk traits.

This paper reports genetic parameters for lamb survival and mortality traits on sheep farms in New Zealand. Lamb survival and mortality records were obtained from 38 flocks (103,357 lambs) from 5 yr of lambing data (2007 to 2011) and include many breeds and their crosses (predominantly Romney, Perendale, Coopworth, and Texel). A number of models were tested, all including environmental weather effects and investigating the random environmental effect of dam and litter (dam/year) as well as logit transformation for binary traits. Total heritability (direct + maternal) estimates were low for lamb viability at birth (0.01), lamb death risk to dystocia (0.01), and lamb death risk to starvation exposure (0.01) from birth to 3 d of age in an analysis accounting for direct and maternal genetic effects and the maternal environmental effects. Lamb survival heritabilities reported are very low (total heritabilities range from 0.02 to 0.06). The total heritabilities for the lamb death risk traits are lower than reported estimates of survival to 3 d of age or to weaning suggesting selection for the postmortem traits are not warranted at this time within these flocks. The total heritability for lamb birth weight was moderate (0.38) and the genetic correlations with the lamb death risk traits suggested that directional selection on lamb birth weight would have an effect on survival, although it is likely to have a nonlinear effect and therefore an optimum birth weight at which survival is maximized. This study has also shown that the total heritabilities may be overestimated when not accounting for maternal genetic and environment effects and in particular not accounting for the random environmental effect of litter (dam/year).

Gender differences in diastolic function among youth.

BACKGROUND: Youth were studied to determine the influence of gender on diastolic function, which has been shown to express abnormalities early in the course of congestive heart failure. METHODS: The study participants were 121 normotensive individuals (53 girls, 68 boys) ages 14 to 18 years. Demographics, hemodynamics, and Doppler-derived indices of diastolic function were collected. Dependent measures of diastolic function were the ratio of early (E) to late (A) peak filling velocities and the isovolumetric relaxation time (IVRT). RESULTS: The girls had a higher relative wall thickness (RWT) (36.58% +/- 4.59% vs 34.60% +/- 4.01%; p < 0.02), higher A (48.40 +/- 8.47 cm/s vs 42.36 +/- 10.43 cm/s; p < 0.001), a lower E/A ratio (1.96 +/- 0.40 vs 2.38 +/- 0.68; p < 0.01), and a shorter IVRT (51.80 +/- 11.14 ms vs 59.00 +/- 14.36 ms; p < 0.01) than the boys. The differences in deceleration time were not significant (181.30 +/- 81.33 ms vs 170.30 +/- 31.06 ms). Hierarchical stepwise regression analysis predicting E/A ratio found gender (male > female) to be the best predictor (R (2 )= 0.09) followed by heart rate (R (2) increase = 0.07; total R (2 )= 0.15; p < 0.01) and by RWT (R (2) increase = 0.05; total R (2 )= 0.21; p < 0.015). For IVRT prediction, gender (male > female) was the best predictor (R (2 )= 0.11), followed by total peripheral resistance (R (2) increase = 0.06; total R (2 )= 0.17; p < 0.017). CONCLUSION: The study data indicate that gender differences in diastolic function exist already in youth. Girls show a higher RWT, a lower E/A ratio, and a shorter IVRT. The implications of these differences for cardiovascular morbidity and mortality of the two genders require attention.

Family history of hypertension and left ventricular mass in youth: possible mediating parameters.

Whether positive family history (FH) of essential hypertension (EH) in normotensive youth is associated with increased left ventricular mass (LVM) and hemodynamic, anthropometric, and demographic parameters previously associated with increased LVM in adults is unknown. To examine these issues, 323 healthy youth (mean age, 13.6 +/- 1.3 years), 194 with positive FH of EH (61% African Americans, 39% whites) and 129 with negative FH of EH (33% African Americans, 67% whites) were evaluated. Hemodynamics were measured at rest and during four stressors (ie, postural change, car driving simulation, video game, forehead cold). Echocardiographic-derived measures of LVM were indexed separately to body surface area and height(2.7). Controlling for age and race differences (ie, 74% of African Americans v 47% of whites had positive FH), the positive FH group exhibited greater LVM/height(2.7), LVM/body surface area, higher systolic (SBP) and diastolic blood pressures (DBP), and total peripheral resistance index (TPRI) and lower cardiac index at rest (P < .05 for all). The positive FH group also displayed higher peak SBP or DBP and higher TPRI increases to each stressor and came from lower socioeconomic status backgrounds (P < .05 for all). Regression analyses indicated that FH of EH was not a significant determinant of LVM/height(2.7) after accounting for contributions of gender (greater in men), general adiposity, resting cardiac index and blood pressure (BP), and TPRI responsivity to video game and cold stimulation (P < .05 for all). Thus, greater LVM index in positive FH of EH youth appears in part related to their greater BP and TPRI at rest and during stress.

Prompting methods affect the accuracy of children's school lunch recalls.

OBJECTIVES: To evaluate the feasibility of implementing 3 specific prompting methods among students in the first and fourth grades (mean age = 7.2 and 10.1 years, respectively), to validate recall accuracy of first- and fourth-grade students against observation, to develop a single measure of inaccuracy that cumulated errors in reporting food items and amounts without allowing underreporting and overreporting to cancel each other, and to establish information regarding the measure of inaccuracy for use in future studies. DESIGN: Children were interviewed the morning after they were observed eating lunch provided by the school. Interviews included free recall, nonsuggestive prompted recall, and specific prompted recall (either preference, food category, or visual). SUBJECTS/SETTING: Ninety-six children (48 students per grade) were studied--32 per the specific prompting method--stratified by grade, sex, and ethnicity (African-American or white). Specific prompting method was randomly assigned to children within strata. STATISTICAL ANALYSIS: Food items were categorized and weighted as: combination entree = 2, condiments = 1/3, and other = 1. To calculate inaccuracy of recall, absolute differences between amounts reported and observed eaten were calculated for each item and then multiplied by each item's weight; these values were then summed across all items for each child. Inaccuracy of recall was determined before specific prompting and after specific prompting and for the difference (inaccuracy after specific prompting minus inaccuracy before specific prompting). RESULTS: Before specific prompting, median inaccuracy was 2.7 servings for the 48 first-grade students and 1.7 servings for the 48 fourth-grade students. The median difference in inaccuracy from before to after specific prompting was 0 for both grades. Specific prompting increased recall accuracy for 9 first-graders and 12 fourth-graders, but decreased recall accuracy for 21 first-graders and 7 fourth-graders, and did not change recall accuracy for 18 first-graders and 29 fourth-graders. Among children whose recall accuracy increased after specific prompting, 5 first-graders and 8 fourth-graders received prompting for food category. APPLICATIONS/CONCLUSIONS: Among first-grade students, specific prompting (either preference, food category, or visual) may hurt more than help recall accuracy. Among fourth-grade students, prompting for food category yields small gains in recall accuracy with minimal losses. Validation studies are needed with larger sample sizes to determine prompting methods that produce more accurate dietary recalls from children of various socioeconomic status groups, other racial/ethnic groups, and at other meals.

Hemodynamic function at rest, during acute stress, and in the field: predictors of cardiac structure and function 2 years later in youth.

Left ventricular hypertrophy is an independent predictor of cardiovascular morbidity and mortality. However, predictors of cardiac structure and function in youth are not completely understood. On 2 occasions (2.3 years apart), we examined 146 youth aged initially 10 to 19 years (mean age, 14.2+/-1.8 years). On the initial visit, hemodynamic function was assessed at rest, during laboratory stress (ie, orthostasis, car-driving simulation, video game, and forehead cold), and in the field (ie, ambulatory blood pressure). Quantitative M-mode echocardiograms were obtained on both visits. On both visits, black compared with white youth had higher resting laboratory systolic blood pressure (P<0.02), greater relative wall thickness (P<0.003), greater left ventricular mass indexed by either body surface area or height(2.7) (P<0.01 for both), and lower midwall fractional shortening ratio (P<0.05). Hierarchical stepwise regression analysis indicated that significant independent predictors of follow-up left ventricular mass/height(2. 7) were the initial evaluation of left ventricular mass/height(2.7), body mass index, gender (males more than females), and supine resting total peripheral resistance (final model R(2)=0.53). Left ventricular mass/body surface area was predicted by initial left ventricular mass/body surface area, weight, gender, mean supine resting total peripheral resistance, and systolic pressure response to car-driving simulation (final model R(2)=0.48). Midwall fractional shortening was predicted by initial midwall fractional shortening, race (white more than black), and lower mean supine total peripheral resistance (final model R(2)=0.13). The clinical significance of these findings and their implications for improved prevention of cardiovascular diseases are yet to be determined.

Children's dietary recalls: the salience of entree and liking for foods on accuracy and order of reporting.

This study investigated the impact of entree and liking for foods on the accuracy and order of reporting on children's school lunch recalls. Data were collected during a series of studies to investigate children's lunch recalls from a cognitive processing approach to understand better how children remember what they have eaten. Fourth-grade children from four schools were randomly selected, observed eating lunch, and interviewed the same (n = 89) or next (n = 148) day. Foods were classified as matches (observed and reported eaten), omissions (observed but not reported eaten), or phantoms (not observed but reported eaten), and corresponding rates were calculated. Statistical analyses included z tests and permutation tests. For same- and next-day recalls, children were more likely to report entree than other meal components earlier in the interview. For next-day recalls, the phantom rate for the remaining items was lower for children who reported entrees accurately versus inaccurately. For items liked "a lot" compared with items "not liked a lot," match rates were higher for next-day recalls, and phantom rates were lower for both same- and next-day recalls. Because entree and liking for foods appear to play salient roles in children's dietary recalls, these results provide guidance regarding the development of specific prompts to increase the accuracy of children's dietary recalls.

Assessment of self-reported anger expression in youth.

Internal consistency, temporal stability, and principal components structures of two self-report anger expression scales used in pediatric health research were examined in 415 youth (216 White, 199 Black; 191 boys, 224 girls; mean age 14.7 years). Participants completed the Anger Expression Scale (AXS) and the Pediatric Anger Expression Scale (PAES) on two occasions separated by approximately 1 year. Psychometric properties of the two scales were examined and compared with those reported by the scale authors. For both the AXS and the PAES, estimates of internal consistency (Cronbach s alpha) were acceptable and comparable to values reported by scale authors. Temporal stability of both scales was significant over 1 year. Principal components structures for both scales were similar to those reported by scale authors. Results were generally consistent for age groupings (<13, 13 years), ethnicity, and gender. It is concluded that further research using the AXS and PAES is warranted. The stability of anger expression over time and the assessment of anger suppression is discussed.

Impact of gender, ethnicity, meal component, and time interval between eating and reporting on accuracy of fourth-graders' self-reports of school lunch.

OBJECTIVE: To validate fourth-graders' self-reports of school lunch by comparing their reports to lunch observations, and to determine the impact on accuracy of gender, ethnicity, meal component, and time interval between eating and reporting. DESIGN: Students were randomly selected, observed eating lunch, and interviewed the same day, next day, or Monday regarding Friday's lunch. Accuracy of reporting items was determined by tallying matched foods (items reported and observed), phantom foods (items reported but not observed), and omitted foods (items not reported but observed). Accuracy of reporting amount eaten was determined by calculating absolute and arithmetic differences. SUBJECTS: Subjects were 260 students: 89 same-day, 148 next-day, and 23 Monday recalls; 59 whites (30 boys) and 201 blacks (103 boys) from four schools. STATISTICAL ANALYSES: Rates for matched, phantom, and omitted foods; analysis of variance; Friedman's nonparametric analog of analysis of variance; Student-Newman-Keuls' post hoc comparisons. RESULTS: In regard to reporting items, the respective rates for matched, phantom, and omitted foods were 84%, 5%, and 16% for same-day recalls; 68%, 13%, and 32% for next-day recalls; and 38%, 48%, and 62% for Monday recalls. Rates for omitted and phantom foods were higher for Monday recalls than for next-day recalls, which were higher than for same-day recalls (P < .05 for all). In regard to reporting amounts, analysis by gender, ethnicity, and time interval failed to yield significant main or interaction effects. When children correctly reported items eaten, they were quite accurate in reporting amounts eaten. Omitted food rates were lowest for beverage, followed by entree, and highest for miscellaneous and condiment. APPLICATIONS: Even under the best conditions (ie, reporting within 90 minutes after eating school lunch), children have difficulty accurately reporting what they have eaten. As the time interval between eating and reporting increases, accuracy decreases markedly. Techniques that improve reporting of items eaten should result in improved accuracy of reporting amounts eaten.

Ventilator management of infants before extracorporeal membrane oxygenation.

The aim of this project was to review the course of infants referred for consideration of extracorporeal membrane oxygenation (ECMO) to identify maximal ventilator settings that, when exceeded, did not provide clinical benefit to the patient. These settings might then be used in defining failure of conventional mechanical ventilation. We reviewed referral records and hospital charts of all infants treated for severe respiratory failure due to meconium aspiration syndrome during the 52.5 month period from March 15, 1985, to August 1, 1989. At an inspiratory pressure > 35 cm H2O, 75% (43/57) of patients eventually required ECMO, and 28% (4/14) of the infants who did not receive ECMO died. When the inspiratory pressure was > or = 40 cm H2O, 39/49 patients required ECMO, and 30% (3/10) of those not treated with ECMO died. Once the inspiratory pressure was > 45 cm H2O, 91% (29/32) of patients required ECMO, and only one third of those not treated with ECMO survived. Although the limitations for conventional therapy suggested in this paper may be helpful to clinicians, each center needs to establish guidelines for maximal conventional ventilator support. If these guidelines are clearly defined, alternative methods of therapy can be used once these criteria are achieved.

"How do you remember you ate...?": a Delphi technique study to identify retrieval categories from fourth-grade children.

OBJECTIVE: To develop and validate a consensus set of retrieval categories for how children remember what they have eaten, and to relate retrieval categories to accuracy of reporting items eaten during school lunch. DESIGN: A Delphi technique study was conducted using 10 psychologists. The subject matter consisted of responses transcribed from interviews conducted with 89 randomly selected fourth graders within 90 minutes of eating. Retrieval categories were evaluated for accuracy by comparing students' self-reported lunch intake with observation. STATISTICAL ANALYSES: For round 1, a centroid hierarchical cluster analysis was used to identify common sets of rating pairs to propose categories for reaching consensus. For rounds 2 and 3, percent of agreement was calculated. Accuracy was tabulated across meal items and student use by retrieval category. RESULTS: After round 3, we found that 23 "near-consensus" categories were used by at least eight raters. Six categories were used 60% of the time, 4 were used 20% of the time, and 5 were used 15% of the time. Less frequently used categories were combined with similar, more frequently used categories for a total of 16 categories. Students used a large variety of retrieval categories when accurately reporting consumption. Of the 16 categories, 12 were used similarly by both accurate and inaccurate students. Where there were differences in accuracy by retrieval category, the more accurate students used "taste/smell/texture" and "visual" in deference to "order items consumed" and "oral cue still present." APPLICATIONS: These categories provide insight into the broad range of retrieval categories that children use and provide direction for researchers to design and study specific cues to enhance the accuracy of children's self-reports of diet.

A measure of stages of change in fruit and vegetable consumption among fourth- and fifth-grade school children: reliability and validity.

OBJECTIVE: We developed, pilot-tested, and field-applied a stages of change questionnaire regarding fruit and vegetable (F&V) consumption among fourth- and fifth-grade students. METHODS: The design included cross-sectional assessment of internal consistency and construct validity, and 2-week and 7-week longitudinal assessment of test-retest reliability. Subjects included 134 students from one school for pilot-testing and 252 from two schools for field application. Thirty-two questions from McConnaughy et al's stages of change questionnaire were adapted and pilot-tested; minor revisions were made for field application. Statistical analyses included principal components analysis to identify subscales; cluster analysis to identify subgroups within students; Cronbach's alpha coefficient to assess internal consistencies; Pearson product-moment correlations to assess test-retest reliabilities; and oneway ANOVA's by F&V stages of change clusters with actual F&V consumption, F&V self-efficacy subscales, F&V preferences, and F&V outcome expectations subscales to determine construct validity. RESULTS: Principal components analysis from the field application indicated two subscales (precontemplation and beyond precontemplation) accounting for 39.5% of variance. Cluster analysis indicated 6 interpretable clusters; 2 (n = 63) provided responses inconsistent with the stages of change theory and 4 (n = 189) provided responses consistent with the theory. Internal consistencies and test-retest reliabilities were acceptable. Students in the "beyond precontemplation" clusters had higher levels of self-efficacy and outcome expectations regarding eating F&V. CONCLUSIONS: Measuring stages of change other than the precontemplation stage in F&V consumption among elementary school children is problematic. Perhaps the theoretical concept does not apply to children, or elementary school children lack the ability to comprehend the questions measuring the concept, or the approach used was not entirely appropriate.

A comparative investigation in dogs: 2-year morphometric results of the dental implant--bone interface.

One hundred twenty titanium and ceramic root-form and titanium blade implants were placed into 30 dog mandibles. Twenty-four implants in six control dogs (in situ for 5 months) did not receive prostheses. Ninety-six implants in 24 dogs supported prostheses for 6, 12, 18, or 24 months. Computerized morphometry data presented the percent of the implant surface apposed directly by bone. A three-way factorial analysis of variance was used to assess significance. Individual implant means ranged from 0% (mobile implant) to 71% bone adaptation. From these data, two-stage titanium root-form implants were shown to be apposed by more bone than the other five systems, and overall, titanium implant systems were apposed by more bone than ceramic systems. Between 41% and 50% of the surface of integrated ceramic implants were apposed by bone, whereas between 50% and 65% of the surfaces of titanium implants were apposed by bone. Also, two-stage surgery for blade implants appears important for implant success. Furthermore, the use of Nomarski differential illumination appears to be useful for examining the quality of interfacial bone to correlate with the amount of bone quantified by morphometric protocols.

Dentists' perceptions of the variety of dental services provided for children.

The purpose of this project was to describe the variety of dental services provided to child patients by general dentists and pediatric dentists. A survey was mailed to a random sample of 2000 general dentists and 1000 pediatric dentists requesting information about the dental services provided to children. Six hundred sixty-two general dentists (33 percent) and 492 pediatric dentists (49 percent) responded. Pediatric dentists reported more frequently obtaining informed consent (p < .0001), placing strip crowns (p < .0001), steel crowns (p < .0001) and pulp treatment procedures (p < .0001). Sealant use in both groups was high but the general dentists reported more frequently sealing occlusal surfaces with incipient caries (p < .001). There were differences in the reported provision of orthodontic services. The general dentists were more likely to refer children for treatment while the pediatric dentists reported they performed limited or comprehensive orthodontic treatment (p < .0001). The results of the survey demonstrate that pediatric dentists perceive that they provide a broader scope of restorative and orthodontic services.

Dentists' perceptions of selected characteristics of their child patients.

The purpose of this project was to examine the perceptions of both general and pediatric dentists regarding selected characteristics of the children they treat. A survey including questions on patients' ages, caries activity estimates, and types of patients treated was mailed once to a national random sample of 2,000 general and 1,000 pediatric dentists. The respondents provided a reasonable distribution by age and location, with the majority (69%) in practice more than 10 years. The pediatric dentists who responded perceive that they treat a younger population of child patients with more caries activity (P < 0.001), except in those patients older than 12 years. They also perceive that their patients pools include a larger percentage of patients with handicapping conditions (P < 0.01), behavior problems (P < 0.001) and patients who require treatment with general anesthesia (P < 0.001) than do the general dentists.

A predictive model for the polymerization of photo-activated resin composites.

This study investigated the relative significance of irradiation duration (20, 40, 60, or 80 seconds) and intensity; filler type (Silux Plus, a microfill or P-50, a hybrid); and shade (Universal or Gray) on the polymerization of resin composite within the depth of a simulated photopolymerized restoration. From the data, a mathematical model that predicts the extent of resin polymerization based upon the above stated variables was generated. The monomer conversion of specimens was determined by infrared spectroscopy. The results are of great clinical use and indicate that the most significant factor influencing resin composite polymerization is thickness of overlying resin composite. Both duration of exposure and light intensity demonstrate high and equal impact. Color and filler type have only minimal influence. The predictive model for resin composite polymerization provided a very good fit (r2 = .949).

The use of behavior management techniques by dentists across practitioner type, age, and geographic region.

The purpose of this project was to describe the behavior management procedures employed for child dental patients based on practitioner type (general dentist vs. pediatric dentist), age, and geographic location. A survey of practice characteristics, which included questions relating to child behavior management, was mailed once to a national random sample of 3000 dentists--2000 general dentists and 1000 pediatric dentists. The pediatric dentists who responded employed a broader spectrum of management techniques than did the general dentists. Significant regional and practitioner age differences were reported in the use of behavior management techniques. The use of sedation and general anesthesia was reported more frequently in the western regions. Of the five age groups, the 40- to 49-year-old age group reported using the broadest spectrum of behavior management techniques. The survey revealed practitioner type, age, and regional differences in the child behavior management procedures employed by dentists.

Factors affecting cure at depths within light-activated resin composites.

When confronted with all the variables that are influential in maximizing the cure in light-activated resin composites, a practitioner may require information that ranks the relative importance of these parameters, so that clinical time can be best utilized. The purpose of this study was to determine simultaneously the relative impact of filler type (hybrid or microfill), composite shade (universal or gray), exposure duration (20, 40, 60 and 80 seconds) and source intensity (800, 578, 400 and 233 mW/cm2) on the extent of cure in light-activated composite at selected depths (top surface, 1, 2, and 3 mm) of a simulated restoration. Thin wafers of composite (P-50 and Silux Plus) were made between a cured composite underlay and varying thicknesses of cured overlay to obtain a wafer that reproduced the curing environment within a cylinder of composite. The monomer conversion of each specimen was obtained by infrared spectroscopic techniques. Analysis of variance was used to determine the significance of factors contributing to the cure of composite at each thickness of overlay used. At the surface, filler type, exposure duration and resin shade predominated as the most influential factors respectively. At 1 mm depth, the order of influential factors were exposure duration, filler type and source intensity. At depths of 2 mm and more, the overwhelming influences on cure were related solely to source intensity and exposure duration. Resin shade and filler type exerted minimal influence at these depths.

Gender differences in the characteristics of dental services provided for children.

The purpose of this project was to describe the differences and similarities in the practice of dentistry for children by male and female dentists. A once-mailed survey with a series of questions regarding the characteristics of their dental practices was sent to a random sample of 3,000 dentists. There were 1,154 useable responses (39 percent). Approximately 8 percent of the respondents were women, which is representative of the percentage of female dentists practicing in the United States. Chi square analysis was employed. There were differences in the practice characteristics of the male and female dentists responding to this survey. The female respondents were: significantly younger; had been in practice for a shorter period of time; more likely to be employees rather than solo practitioners; more likely to treat younger patients; less likely to do comprehensive orthodontic treatment and more likely to use physical restraints than their male counterparts.