Assessment of perineural spread in advanced cutaneous squamous cell carcinomas treated with immunotherapy

BACKGROUND

Cutaneous squamous cell carcinoma (CSCC) has a propensity for perineural spread (PNS) which is associated with poorer treatment outcomes. Immunotherapy is the new standard of care treatment for advanced CSCC resulting in durable responses. PNS is not captured by traditional response assessment criteria used in clinical trials, e.g. RECIST 1.1, and there is limited literature documenting radiological PNS responses to immunotherapy. In this study we assess PNS responses to immunotherapy using a modified grading system.

METHODS

This is an Australian single-center retrospective review of patients with advanced CSCC who were treated with immunotherapy between April 2018 and February 2022 who had evidence of PNS on pre-treatment magnetic-resonance imaging (MRI). The primary outcome was blinded overall radiological response in PNS using graded radiological criteria, post-commencement of immunotherapy. Three defined timepoints (< 5 months, 5-10 months, > 10 months) were reviewed. Secondary outcomes included a correlation between RECIST 1.1 and PNS assessments and the assessment of PNS on fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT).

RESULTS

Twenty CSCC patients treated with immunotherapy were identified. Median age was 75.7 years and 75% (n = 15) were male. All patients had locoregionally advanced disease and no distant metastases. Median follow-up was 18.5 months (range: 2-59). 70% (n = 14) demonstrated a PNS response by 5 months. Three patients experienced pseudoprogression. One patient had PNS progression by the end of study follow up. RECIST 1.1 and PNS responses were largely concordant at > 10 months (Cohen's Kappa 0.62). 5/14 cases had features suspicious for PNS on FDG-PET/CT.

CONCLUSIONS

PNS response to immunotherapy can be documented on MRI using graded radiological criteria. High response rates were seen in PNS with the use of immunotherapy in this cohort and these responses were largely concordant with RECIST 1.1 assessments. FDG-PET/CT demonstrated limited sensitivity in the detection of PNS.

Bladder leiomyoma and the utility of 18F-Fluorodeoxyglucose-Positron Emission Tomography - a Case Report

Bladder leiomyomas are rare neoplasms and various diagnostic methods are available to assist in confirming diagnosis preoperatively. Presented here is a case of bladder leiomyoma in a 41-year-old female who presented with urinary symptoms and right thigh pain. Imaging revealed a soft tissue density mass in the bladder wall. However concerns of a leiomyosarcoma remained. An 18F-fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) demonstrated low FDG uptake and absence of metastatic lesions. In combination with operative findings, the tumor allowed for localized resection instead of more invasive partial cystectomy. Therefore, FDG-PET might be used to support the diagnosis of leiomyoma and potentially facilitate a less aggressive surgical management.

Microbial Indicators of Dental Health, Dysbiosis, and Early Childhood Caries

Dental caries lesions are a clinical manifestation of disease, preceded by microbial dysbiosis, which is poorly characterized and thought to be associated with saccharolytic taxa. Here, we assessed the associations between the oral microbiome of children and various caries risk factors such as demographics and behavioral and clinical data across early childhood and characterized over time the salivary and dental plaque microbiome of children before clinical diagnosis of caries lesions. Children (N = 266) were examined clinically at ~1, 2.5, 4, and 6.5 y of age. The microbiome samples were collected at 1, 2.5, and 4 y. Caries groups consisted of children who remained caries free (International Caries Detection and Assessment System [ICDAS] = 0) at all time points (CFAT) (n = 50); children diagnosed with caries (ICDAS ≥ 1) at 6.5 y (C6.5), 4 y (C4), or 2.5 y of age (C2.5); and children with early caries or advanced caries lesions at specific time points. Microbial community analyses were performed on zero-radius operational taxonomic units (zOTUs) obtained from V4 of 16S ribosomal RNA gene amplicon sequences. The oral microbiome of the children was affected by various factors, including antibiotic use, demographics, and dietary habits of the children and their caregivers. At all time points, various risk factors explained more of the variation in the dental plaque microbiome than in saliva. At 1 y, composition of saliva of the C4 group differed from that of the CFAT group, while at 2.5 y, this difference was observed only in plaque. At 4 y, multiple salivary and plaque zOTUs of genera Prevotella and Leptotrichia were significantly higher in samples of the C6.5 group than those of the CFAT group. In conclusion, up to 3 y prior to clinical caries detection, the oral microbial communities were already in a state of dysbiosis that was dominated by proteolytic taxa. Plaque discriminated dysbiotic oral ecosystems from healthy ones better than saliva.

Concurrent validity of the short-form Family Impact Scale (FIS-8) in 4-year-old US children

Background

US data on the validity and reliability of the short-form Family Impact Scale (FIS-8; a scale for measuring the impact of a child’s oral condition on his/her family) are lacking.

Methods

Cross-sectional analysis of data on four-year-old US children taking part in a multi-center cohort study. For child-caregiver dyads recruited at child age 12 months, the impact of the child’s oral condition on the family was assessed at age 48 months using the FIS-8, with a subsample of 422 caregivers (from 686 who were approached). Internal consistency reliability was assessed using Cronbach’s α, with concurrent validity assessed against a global family impact item (“How much are your family’s daily lives affected by your child’s teeth, lips, jaws or mouth?”) and a global oral health item (“How would you describe the health of your child’s teeth and mouth?”).

Results

Cronbach’s alpha was 0.83. Although gradients in mean scores across ordinal response categories of the global family impact item were inconsistent, there were marked, consistent gradients across the ordinal categories of the global item on the child’s oral health, with scores highest for those rating their child’s oral health as ‘Poor’.

Conclusions

While the findings provide some evidence for the utility of the FIS in a US child sample, the study’s replication in samples of preschoolers with greater disease experience would be useful.

Do magnetic resonance imaging abnormalities of the non-dominant wrist correlate with ulnar-sided wrist pain in elite tennis players?

OBJECTIVE

Ulnar-sided injuries of the non-dominant wrist are common in elite tennis players that use the double-handed backhand technique. This study aimed to define the relationship between ulnar-sided wrist pain in symptomatic and asymptomatic elite tennis players, and the presence of abnormalities on magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Fourteen symptomatic tennis players, 14 asymptomatic tennis players, and 12 healthy controls who did not play tennis, were analyzed prospectively, after undergoing MRI of their non-dominant wrist. Five anatomical regions were analyzed, thought to relate to ulnar-sided wrist pain. These consisted of the triangular fibrocartilage complex (TFCC), ulnar collateral ligament (UCL), extensor carpi ulnaris tendon (ECU), osseous-articular structures, and ganglia. Images were independently reviewed by two blinded musculoskeletal radiologists.

RESULTS

Non-dominant, ulnar-sided, wrist pain in elite tennis players was not statistically significantly associated with an increased number of MRI abnormalities when compared with asymptomatic tennis players (p > 0.05). However, some evidence of statistical association was seen with an increased prevalence of ECU tendon abnormalities (OR = 8.0, 95% CI = (0.74, 20.00), p = 0.07). A statistically significant increase in MRI abnormalities of osseous structures (OR = 15.1, 95% CI = (1.56, 656.05), p = 0.02) and the dorsal radioulnar ligament (DRUL) (OR = 12.5, 95% CI = (2.15, 111.11), p = 0.03), was observed in symptomatic players compared with controls.

CONCLUSIONS

Non-dominant, ulnar-sided, wrist pain in a subgroup of elite tennis players using a double-handed backhand technique is not associated with a statistically significant increased prevalence of MRI abnormalities when compared with asymptomatic tennis players, other than some evidence of statistical association with ECU tendon abnormalities. Therefore, significance of MRI abnormalities should be interpreted in the context of clinical findings.

Decline in Dental Fluorosis Severity during Adolescence: A Cohort Study

Dental fluorosis occurs from overingestion of fluoride during tooth formation. However, there is little evidence in the literature on whether or how fluorosis prevalence and severity change over time after tooth eruption. Permanent dentition dental examinations were conducted at ages 9, 13, 17, and 23 as part of the Iowa Fluoride Study, which has followed a cohort from birth. Fluorosis was assessed using the Fluorosis Risk Index (FRI) and Russell's criteria for differential diagnosis. Measures of fluorosis severity at the person and tooth level were calculated: second highest FRI score at the person level (the maximum FRI score for each tooth was determined and the tooth with the second highest maximum FRI score was used) and highest FRI score at the tooth level. At both the person and tooth levels, a decline in mild to moderate fluorosis severity was observed across adolescence and young adulthood. Across each pair of adjacent examinations at the person level, for participants with a baseline second highest FRI of 0, most participants stayed at 0 (82% to 91%). Many participants with a baseline second highest FRI of 1 had a follow-up score of 0 (47% to 54%), while about a third had a follow-up score of 1 (34% to 38%), and a lower percentage had an increase to a score of 2 (9% to 15%). For participants with baseline second highest FRI score of 2, between 25% and 44% of participants had follow-up FRI scores each of 0, 1, and 2. Similar patterns were observed at the tooth level. These results were consistent with most of the existing, limited literature. Overall, fluorosis severity, which was initially mild to moderate, tended to decline during adolescence and young adulthood. Additional study of how this trend affects esthetic perceptions of fluorosis is warranted.

Maturation of the Oral Microbiome in Caries-Free Toddlers: A Longitudinal Study

Understanding the development of the oral microbiota in healthy children is of great importance to oral and general health. However, limited data exist on a healthy maturation of the oral microbial ecosystem in children. Moreover, the data are biased by mislabeling “caries-free” populations. Therefore, we aimed to characterize the healthy salivary and dental plaque microbiome in young children. Caries-free (ICDAS [International Caries Detection and Assessment System] score 0) children (n = 119) and their primary caregivers were followed from 1 until 4 y of child age. Salivary and dental plaque samples were collected from the children at 3 time points (T1, ~1 y old; T2, ~2.5 y old; and T3, ~4 y old). Only saliva samples were collected from the caregivers. Bacterial V4 16S ribosomal DNA amplicons were sequenced using Illumina MiSeq. The reads were denoised and mapped to the zero-radius operational taxonomic units (zOTUs). Taxonomy was assigned using HOMD. The microbial profiles of children showed significant differences (P = 0.0001) over time. Various taxa increased, including Fusobacterium, Actinomyces, and Corynebacterium, while others showed significant decreases (e.g., Alloprevotella and Capnocytophaga) in their relative abundances over time. Microbial diversity and child-caregiver similarity increased most between 1 and 2.5 y of age while still not reaching the complexity of the caregivers at 4 y of age. The microbiome at 1 y of age differed the most from those at later time points. A single zOTU (Streptococcus) was present in all samples (n = 925) of the study. A large variation in the proportion of shared zOTUs was observed within an individual child over time (2% to 42% of zOTUs in saliva; 2.5% to 38% in dental plaque). These findings indicate that the oral ecosystem of caries-free toddlers is highly heterogeneous and dynamic with substantial changes in microbial composition over time and only few taxa persisting across the 3 y of the study. The salivary microbiome of 4-y-old children is still distinct from that of their caregivers.

Modulation of Immunity by Lymphatic Dysfunction in Lymphedema

The debilitating condition known as secondary lymphedema frequently occurs after lymphadenectomy and/or radiotherapy for the treatment of cancer. These therapies can damage lymphatic vessels leading to edema, fibrosis, inflammation and dysregulated adipogenesis, which result in profound swelling of an affected limb. Importantly, lymphedema patients often exhibit impaired immune function which predisposes them to a variety of infections. It is known that lymphadenectomy can compromise the acquisition of adaptive immune responses and antibody production; however the cellular mechanisms involved are poorly understood. Here we discuss recent progress in revealing the cellular and molecular mechanisms underlying poor immune function in secondary lymphedema, which has indicated a key role for regulatory T cells in immunosuppression in this disease. Furthermore, the interaction of CD4⁺ T cells and macrophages has been shown to play a role in driving proliferation of lymphatic endothelial cells and aberrant lymphangiogenesis, which contribute to interstitial fluid accumulation in lymphedema. These new insights into the interplay between lymphatic vessels and the immune system in lymphedema will likely provide opportunities for novel therapeutic approaches designed to improve clinical outcomes in this problematic disease.

Fluoride Use in Health Care Settings: Association with Children's Caries Risk

Expanded partnership with the medical community is an important strategy for reducing dental caries disparities. The purpose of this study was to assess the relationship between fluoride (F) "in office" (drops/tablets and/or varnish), as prescribed or applied by a health care professional by age 1 y, and 1) caries development and 2) presence of other caries risk factors or mediators (e.g., socioeconomic status). Child-primary caregiver (PCG) pairs ( N = 1,325) were recruited in Indiana, Iowa, and North Carolina as part of a longitudinal cohort study to validate a caries risk tool for primary health care settings. PCGs completed a caries risk questionnaire, while children received caries examinations per the criteria of the International Caries Detection and Assessment System at ages 1, 2.5, and 4 y. Baseline responses regarding children's history of F in office were tested for association with other caries risk variables and caries experience at ages 2.5 and 4 y via generalized estimating equation models applied to logistic regression. The sample was 48% female, and many children (61%) were Medicaid enrolled. The prevalence of cavitated caries lesions increased from 7% at age 2.5 y to 25% by age 4 y. Children who received F in office were likely deemed at higher caries risk and indeed were significantly ( P < 0.01) more likely to develop cavitated caries lesions by ages 2.5 and 4 y, even after F application (odds ratios: 3.5 and 2.3, respectively). Factors significantly associated with receiving F included the following: child being Medicaid enrolled, not having an employed adult in the household, child and PCG often consuming sugary drinks and snacks, and PCG having recent caries experience. Increased F in office from a health care provider by age 1 y was associated with known caries risk factors. Most (69%) children had never been to the dentist, suggesting that risk factors could be alerting medical providers and/or parents, thereby affecting in-office F recommendations. Differences among states could also be related to state-specific F-varnish reimbursement policies (ClinicalTrials.gov NCT01707797).

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.

Divergent lymphatic drainage routes from the heel to the inguinal region: anatomic study and clinical implications

PURPOSE

To determine routes of lymphatic drainage from the heel to the inguinal lymph nodes to assist in the clinical management of lower limb lymphatic disorders.

METHODS

Six lower limbs from three unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect lymphatic vessels on the medial and lateral sides of the heel. The lymphatic vessel on either side was then injected with a radio-opaque mixture. The lymphatic vessels were traced, photographed, and radiographed to demonstrate the lymphatic pathways from the heel to the inguinal lymph nodes. The final results were transferred to computer for digital image analysis.

RESULTS

Two groups of lymph collecting vessels were identified. The medial group, arising from the skin between the medial malleolus and the Achilles tendon, coursed along the medial side of the leg and thigh to the inguinal lymph nodes. The lateral group, arising from the skin between the lateral malleolus and the Achilles tendon, coursed along the postero-lateral side of the leg to the popliteal fossa. Alternative routes were then identified from the popliteal fossa to the inguinal lymph nodes. The number, size, type, and distribution of lymph vessels and nodes were variable from person to person.

CONCLUSION

Two different lymphatic routes from the heel to the inguinal lymph nodes have been described. This information upgrades current anatomical knowledge and the results will be of benefit for the clinical management of lower limb trauma and malignancy.

Radiologic Manifestations of Senile Lymph Nodes in the Popliteal Fossa

PURPOSE

To determine the radiologic manifestations of senile lymph nodes in the popliteal fossa for radiologic and clinical application.

METHODS

A total of six lower extremities from four unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect the lymphatic vessels commencing from the foot and leg. A 30-gauge needle was inserted into the vessels and injected with a radio-opaque lead oxide mixture. The specimens were radiographed and photographed to demonstrate the lymph nodes in the popliteal fossa. The final results were transferred to the computer for image analysis.

RESULTS

An average of two lymph nodes (range 1 to 3) were found in the popliteal fossa of the lower extremity. They were divided into superficial and deep popliteal groups. The superficial group was located in the superficial layer of the popliteal fossa around the small saphenous vein (SSV). The deep group was close to the popliteal surface of the femur and always located next to the popliteal vein. All lymph nodes were transparent in appearance and contained coiled lymphatic tubules. The size and density of the tubules varied.

CONCLUSION

The radiologic manifestations of senile lymph nodes in the popliteal fossa have been presented and discussed to upgrade our radiologic and anatomical knowledge. This will be of benefit for radiologic and clinical applications.

Genetic Association of MPPED2 and ACTN2 with Dental Caries

The first genome-wide association study of dental caries focused on primary teeth in children aged 3 to 12 yr and nominated several novel genes: ACTN2, EDARADD, EPHA7, LPO, MPPED2, MTR, and ZMPSTE24. Here we interrogated 156 single-nucleotide polymorphisms (SNPs) within these candidate genes for evidence of association with dental caries experience in 13 race- and age-stratified samples from 6 independent studies (n = 3600). Analysis was performed separately for each sample, and results were combined across samples via meta-analysis. MPPED2 was significantly associated with caries via meta-analysis across the 5 childhood samples, with 4 SNPs showing significant associations after gene-wise adjustment for multiple comparisons (p < .0026). These results corroborate the previous genome-wide association study, although the functional role of MPPED2 in caries etiology remains unknown. ACTN2 also showed significant association via meta-analysis across childhood samples (p = .0014). Moreover, in adults, genetic association was observed for ACTN2 SNPs in individual samples (p < .0025), but no single SNP was significant via meta-analysis across all 8 adult samples. Given its compelling biological role in organizing ameloblasts during amelogenesis, this study strengthens the hypothesis that ACTN2 influences caries risk. Results for the other candidate genes neither proved nor precluded their associations with dental caries.

Effects of life-long fluoride intake on bone measures of adolescents: a prospective cohort study

Controversy persists concerning the impact of community water fluoridation on bone health in adults, and few studies have assessed relationships with bone at younger ages. Ecological studies of fluoride's effects showed some increase in bone mineral density of adolescents and young adults in areas with fluoridated water compared with non-fluoridated areas. However, none had individual fluoride exposure measures. To avoid ecological fallacy and reduce bias, we assessed associations of average daily fluoride intake from birth to age 15 yr for Iowa Bone Development Study cohort members with age 15 yr dual-energy x-ray absorptiometry (DXA) bone outcomes (whole body, lumbar spine, and hip), controlling for known determinants (including daily calcium intake, average daily time spent in moderate-to-vigorous intensity physical activity, and physical maturity). Mean (SD) daily fluoride intake was 0.66 mg (0.24) for females and 0.78 mg (0.30) for males. We found no significant relationships between daily fluoride intake and adolescents' bone measures in adjusted models (for 183 females, all p values ≥ .10 and all partial R(2) ≤ 0.02; for 175 males, all p values ≥ .34 and all partial R(2) ≤ 0.01). The findings suggest that fluoride exposures at the typical levels for most US adolescents in fluoridated areas do not have significant effects on bone mineral measures.

Genome-wide association study of primary dentition pit-and-fissure and smooth surface caries

Dental caries continues to be the most common chronic disease in children today. Despite the substantial involvement of genetics in the process of caries development, the specific genes contributing to dental caries remain largely unknown. We performed separate genome-wide association studies of smooth and pit-and-fissure tooth surface caries experience in the primary dentitions of self-reported white children in two samples from Iowa and rural Appalachia. In total, 1,006 children (ages 3-12 years) were included for smooth surface analysis, and 979 children (ages 4-14 years) for pit-and-fissure surface analysis. Associations were tested for more than 1.2 million single nucleotide polymorphisms, either genotyped or imputed. We detected genome-wide significant signals in KPNA4 (p value = 2.0E-9), and suggestive signals in ITGAL (p value = 2.1E-7) and PLUNC family genes (p value = 2.0E-6), thus nominating these novel loci as putative caries susceptibility genes. We also replicated associations observed in previous studies for MPPED2 (p value = 6.9E-6), AJAP1 (p value = 1.6E-6) and RPS6KA2 (p value = 7.3E-6). Replication of these associations in additional samples, as well as experimental studies to determine the biological functions of associated genetic variants, are warranted. Ultimately, efforts such as this may lead to a better understanding of caries etiology, and could eventually facilitate the development of new interventions and preventive measures.

Alternative lymphatic drainage routes from the lateral heel to the inguinal lymph nodes: anatomic study and clinical implications

BACKGROUND

The route of lymphatic drainage from the heel to the inguinal lymph nodes is required to be accurately evaluated for clinical needs.

METHODS

Seven lower limbs from four unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect the lymphatic vessel on the lateral side of the heel. The vessel was then injected with a radio-opaque lead oxide mixture. The vessel was traced, photographed and radiographed to demonstrate the lymphatic pathways from the lateral heel to the inguinal lymph nodes. The final results were transferred to the computer for image analysis.

RESULTS

The lymph collecting vessel arising from the skin of the fossa between the lateral malleolus and the Achilles tendon ran along the posterolateral side of the leg, deep to the superficial fascia. From the popliteal fossa to the inguinal lymph nodes, three lymphatic routes were found: (i) via the superficial tissue of the medial side of the thigh; (ii) running with the superficial femoral blood vessels; (iii) running between the sciatic nerve and the profunda femoral vessels. The number and type of lymph nodes found in the popliteal fossa and femoral triangle were different from person to person.

CONCLUSION

Actual and accurate lymphatic routes from the skin above the posterolateral heel to the inguinal lymph nodes have been described. This information upgrades our anatomical knowledge and the results will be of benefit for the clinical management of trauma and malignancies in the lower limb.

Genome-wide association scan for childhood caries implicates novel genes

Dental caries is the most common chronic disease in children and a major public health concern due to its increasing incidence, serious health and social co-morbidities, and socio-demographic disparities in disease burden. We performed the first genome-wide association scan for dental caries to identify associated genetic loci and nominate candidate genes affecting tooth decay in 1305 US children ages 3-12 yrs. Affection status was defined as 1 or more primary teeth with evidence of decay based on intra-oral examination. No associations met strict criteria for genome-wide significance (p < 10E-7); however, several loci (ACTN2, MTR, and EDARADD, MPPED2, and LPO) with plausible biological roles in dental caries exhibited suggestive evidence for association. Analyses stratified by home fluoride level yielded additional suggestive loci, including TFIP11 in the low-fluoride group, and EPHA7 and ZMPSTE24 in the sufficient-fluoride group. Suggestive loci were tested but not significantly replicated in an independent sample (N = 1695, ages 2-7 yrs) after adjustment for multiple comparisons. This study reinforces the complexity of dental caries, suggesting that numerous loci, mostly having small effects, are involved in cariogenesis. Verification/replication of suggestive loci may highlight biological mechanisms and/or pathways leading to a fuller understanding of the genetic risks for dental caries.

Streptococcus mutans strains recovered from caries-active or caries-free individuals differ in sensitivity to host antimicrobial peptides

Antimicrobial peptides (AMPs) are among the repertoire of host innate immune defenses. In the oral cavity, several AMPs are present in saliva and have antimicrobial activities against oral bacteria, including Streptococcus mutans, a primary etiological agent of dental caries. In this study, we hypothesized that unique S. mutans strains, as determined by DNA fingerprinting from sixty 13-year-old subjects with or without experience of caries, would have different susceptibilities to α-defensins-1-3 (HNP-1-3), β-defensins-2-3 (HBD-2-3) and LL-37. The salivary levels of these peptides in subjects were also measured by enzyme-linked immunosorbent assays. We found that S. mutans strains from children with active caries showed greater resistance to salivary HNP-1-2, HBD-2-3 and LL-37 at varying concentrations than those from caries-free subjects. In addition, combinations of these peptides increased their antimicrobial activity against S. mutans either additively or synergistically. The salivary levels of these peptides were highly variable among subjects with no correlation to host caries experience. However, the levels of a number of these peptides in saliva appeared to be positively correlated within an individual. Our findings suggest that the relative ability of S. mutans to resist host salivary AMPs may be considered a potential virulence factor for this species such that S. mutans strains that are more resistant to these peptides may have an ecological advantage to preferentially colonize within dental plaque and increase the risk of dental caries.

Development of gold standard ion-selective electrode-based methods for fluoride analysis

BACKGROUND/AIMS

Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research.

METHODS

A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode.

RESULTS

Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies.

CONCLUSION

The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values.

Association between enamel hypoplasia and dental caries in primary second molars: a cohort study

The purpose of this study was to assess the longitudinal relationships between enamel hypoplasia and caries experience of primary second molars. The study sample was 491 subjects who received dental examinations at both age 5 and 9 by the calibrated examiners. Four primary second molars (n = 1,892) were scored for the presence of enamel hypoplasia for each participant. Caries presence and number of decayed and filled surfaces (dfs) were determined at age 5 and 9. The relationships between enamel hypoplasia and caries experience were assessed. Among primary second molars, 3.9% of children and 1.7% of primary second molars had enamel hypoplasia. At age 5, 36.8% of children with hypoplasia had caries, while 16.9% of children without enamel hypoplasia had caries. At age 9, the corresponding numbers were 52.6% for children with hypoplasia and 34.5% for children without hypoplasia, respectively. At the tooth level, for age 5, 28.1% of teeth with hypoplasia had caries (mean dfs = 0.40), and 7.6% of teeth without hypoplasia had caries (mean dfs = 0.11). At age 9, the corresponding numbers were 41.9% (mean dfs = 0.76) for teeth with hypoplasia and 18.3% (mean dfs = 0.34) for teeth without hypoplasia. In multivariable logistic regression analyses, teeth of subjects with enamel hypoplasia had a significantly higher risk for caries at age 5 and 9 after controlling for other risk factors. Enamel hypoplasia appears to be a significant risk factor for caries and should be considered in caries risk assessment.

The larval midgut of Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae): light and electron microscopy studies of the epithelial cells

The morphology of the midgut epithelium cells of Anticarsia gemmatalis (Hübner) larvae is described by light and transmission electron microscopy. The midgut of A. gemmatalis is the largest portion of the digestive tract, with three distinct regions: proximal, media and distal. Its wall is formed by pseudostratified columnar epithelial tissue having four cell types: columnar, goblet, regenerative, and endocrine cells. The columnar cells are numerous and long, with the apical portion showing many lengthy microvilli and the basal portion invaginations forming a basal labyrinth. The goblet cells have a large goblet-shaped central cavity delimited by cytoplasmic projections filled with mitochondria. The regenerative cells present electron-dense cytoplasm and few organelles. The endocrine cells are characterized by electron-dense secretory granules, usually concentrated in the cytoplasm basal region.

Angiosomes of the brachial plexus: an anatomical study

This anatomical study analyzed the neurovascular relationships of the brachial plexus. Ten fresh cadaveric brachial plexuses were examined after injection of the arterial system. The vascular anatomical features of the brachial plexus were documented with microdissection after lead oxide/gelatin injection. The specimens were analyzed by using radiography (including digital subtraction techniques) and light-microscopic, macroscopic, and digital photography. Four angiosomes, based on the subclavian, axillary, vertebral, and dorsal scapular arteries, were observed. As noted in previous angiosome studies, connections between angiosome territories lay within tissues, in this case, nerve trunks. Nutrient vessels penetrated nerve trunks at points of branching within the brachial plexus, with a Y-shaped mode of division on entry. The vascular supply was markedly rich, often with true anastomotic connections occurring within the nerves. There was much variation in supply, depending on the vascular anatomical features of the subclavian artery.

Socio-demographic features and fluoride technologies contributing to higher fluorosis scores in permanent teeth of Canadian children

OBJECTIVE

To examine levels of fluorosis among children in two Canadian communities exposed to fluoride.

BACKGROUND

One community had discontinued fluoride, the other had maintained it. Water supplies, however, were fluoridated for all the children when their esthetically important teeth were mineralized.

METHODS

We examined 8,277 children to assess Thystrup-Fejerskov Index (TFI) scores. Multivariate Poisson regression models were used to identify the relationship between TFI and water fluoride status, age, gender, SES, and dietary and fluoride exposure histories (supplements, rinses, toothpaste amount, tooth brushing frequency, and tooth brushing starting age). Parent(s) completed questionnaires.

RESULTS

Overall, levels of fluorosis were low to mild, with residents of the fluoridation-ended communities having marginally higher TFI scores than those of the still-fluoridated community. Females had higher TFI scores than males. Children aged 10 years or more had higher TFI scores than younger children. Consuming bottled water between birth and 6 months of age was protective. Exposure to fluoridation technologies was consistently associated with fluorosis experience. Children who began brushing with fluoride toothpaste between their first and second birthdays had higher TFI scores than those who began between their second and third birthdays, regardless of daily brushing frequency. Children who regularly used supplements had higher TFI scores than those who did not. Children with a college-educated father had higher TFI scores than those whose fathers had less education.

CONCLUSIONS

Higher fluoride exposure slightly increased the likelihood that a child had a higher TFI score, especially when more fluoridation technologies were used at home.

Fluoride, beverages and dental caries in the primary dentition

Knowledge concerning risk factors for primary dentition caries in young children is incomplete. Models are presented for caries development using longitudinally gathered fluoride exposure and dietary intake data in the Iowa Fluoride Study. Primary tooth caries examinations were conducted at age 5. Dietary (beverage) and fluoride exposure data were gathered longitudinally from age 6 weeks through 4 years (n = 291); 23% had decayed or filled surfaces. Logistic regression revealed that beverage components and toothbrushing made unique contributions to caries experience. Water consumption (36-48 months), milk consumption (24-36 months), and fluoridated toothpaste brushings (36-48 months) were negatively associated with caries; sugared beverages and milk (6 weeks to 12 months) were positively associated. Although fluoride exposure is important, sugared beverages contribute substantially to caries risk, while water and milk consumption and frequent toothbrushing early can have protective effects.

Functional specialization within the cat red nucleus

Magnocellular (RNm) and parvicellular (RNp) divisions of the cat red nucleus (RN) project to the cervical spinal cord. RNp projects more heavily to upper cervical levels and RNm projects more heavily to lower levels. The cells in RN are active during reaching and grasping, and the differences in termination suggest that the divisions influence different musculature during this behavior. However, the spinal termination may not reflect function because most rubrospinal terminations are to interneuronal regions, which can influence motor neurons at other spinal levels. To test for functional differences between RNm and RNp, we selectively stimulated RNm and RNp as well as the efferent fibers from each region. Electromyographic activity was recorded from seven muscles of the cat forelimb during reaching. The activity from each muscle was averaged over several thousand stimuli to detect influences of stimulation on muscle activity. Stimulation within the RN produced a characteristic pattern of poststimulus effects. The digit dorsiflexor, extensor digitorum communis (edc), was most likely to show facilitation, and several other muscles showed suppression. The pattern of activation did not differ between RNm and RNp. In contrast, stimulation of RNp fibers favored facilitation of shoulder muscles (spinodeltoideus and supraspinatus), and stimulation of RNm fibers favored facilitation of digit and wrist muscles (edc, palmaris longus, and extensor carpi ulnaris). Fiber stimulation produced few instances of poststimulus suppression. The results from fiber stimulation indicate that the physiological actions of RNm and RNp match their levels of spinal termination. The complex pattern of facilitation and suppression seen with RN stimulation may reflect synaptic actions within the nucleus.

A pilot study of dental students' esthetic perceptions of computer-generated mild dental fluorosis compared to other conditions

OBJECTIVES

Few studies have considered people's opinions about the esthetics of dental fluorosis. Assessments of fluorosis esthetics can be confounded by differences in a number of clinical factors, including tooth shape, color, contour, and gingival status. This pilot study compared esthetic perceptions of mild fluorosis and other conditions using computer-generated images made from a base set of normal appearing teeth.

METHODS

Entering dental students (n = 61) completed questionnaires about four sets of paired photographs. Three sets consisted of fluorotic teeth (very mild to mild) versus other conditions (diastema, isolated enamel opacity, "normal"/control) and the other pair compared two presentations of mild fluorosis (generalized versus limited to incisal one-third). Six questions, both qualitative and quantitative, were asked about each pair of photographs.

RESULTS

Mild fluorosis was assessed less favorably than normal/control, midline diastema was less favorable than mild fluorosis, and mild fluorosis was less favorable than isolated opacity.

CONCLUSIONS

This approach allows fluorosis to be better compared with other oral conditions because the images are standardized. Additional research with this method is warranted, including more variations in conditions, more comparisons, and other study populations.

Prevalence of dental fluorosis in the primary dentition

OBJECTIVES

This paper presents data on the prevalence of primary tooth fluorosis among children residing in Iowa, and the relationships between fluorosis prevalence and selected measures of fluoride exposures.

METHODS

Children in the study cohort were followed prospectively during the first year of life. This study assessed their home water fluoride concentrations and use of fluoride dentifrice or dietary fluoride supplements. A total of 637 children (320 females and 317 males) were examined for fluorosis using a modification of the TSIF index at age 4 1/2 to 5 years, with 90.4 percent having intact primary dentitions.

RESULTS

74 children (11.6%) had fluorosis present on one or more of their primary teeth, and 71 children (11.1%) had two or more teeth affected. Nearly all fluorosis was mild, with the primary second molar teeth most commonly affected. Fluorosis was significantly associated with higher water fluoride concentration, but not with the use of dentifrice or fluoride supplements.

CONCLUSIONS

The results of this study show that primary tooth fluorosis is relatively uncommon, but is most frequently seen on the posterior teeth, particularly the primary second molars, which form at later stages of development. This finding suggests that primary tooth fluorosis is mostly a postnatal phenomenon, and is associated with higher water fluoride levels.

Patterns of fluoride intake from birth to 36 months

OBJECTIVES

Dental fluorosis prevalence has increased in the United States, Canada, and other nations due to the widespread availability of fluoride in many forms, with fluoride ingestion during the first three years of life appearing most critical in fluorosis etiology. With few contemporary studies of fluoride ingestion in this age group, the purpose of this paper is to describe patterns of estimated fluoride ingestion from birth to 36 months of age from water, dentifrice, and dietary fluoride supplements and combined.

METHODS

Repeated responses to separate series of questions about water intake, use of fluoride dentifrice, and use of fluoride supplements were collected by questionnaire as part of the longitudinal Iowa Fluoride Study and used to estimate fluoride intake. Estimated intake is reported by source and combined at different ages. Effects of subject age and other covariates on fluoride intake were assessed using regression methods appropriate for the analysis of correlated data.

RESULTS

For most children, water fluoride intake was the predominant source, especially through age 12 months. Combined daily fluoride intake increased through 9 months, was lower at 12 and 16 months, and increased again thereafter. Mean intake per unit body weight (bw) was about 0.075 mg F/kg bw through 3 months of age, 0.06 mg F/kg bw at 6 and 9 months, 0.035 mg F/kg bw at 12 and 16 months, and 0.043 mg F/kg bw from 20-36 months. Depending on the threshold chosen (e.g., 0.05 or 0.07 mg F/kg bw), variable percentages of the children exceeded the levels, with percentages greatest during the first 9 months. Regression analyses showed fluoride intake (mg F/kg bw) from 1.5-9 months to decrease with increasing child's age, mother's age, and mother's education, with a complex three-way interaction among these factors. From 12-20 months, fluoride intake increased with increasing child age and decreased with increasing mother's age. No statistically significant relationships were found for fluoride intake from 24-36 months.

CONCLUSIONS

There is considerable variation in fluoride intake across ages and among individuals. Longitudinal studies may be necessary to fully understand the relationships between fluoride ingestion over time and development of fluorosis.

Physical activity and bone measures in young children: the Iowa bone development study

OBJECTIVES

Physical activity has a beneficial effect on bone development in circumpubertal children, although its effect on younger children is uncertain. In this cross-sectional study, we examined associations between physical activity and bone measures in 368 preschool children (mean age: 5.2 years, range: 4-6 years).

DESIGN

Physical activity was measured using 4-day accelerometry readings, parental report of children's usual physical activity, and parental report of children's hours of daily television viewing. Total body and site-specific bone mineral content and area bone mineral density (BMD) were measured by dual energy radiograph absorptiometry.

RESULTS

After adjustment for age and body size, accelerometry measures of physical activity and parental report of usual physical activity were consistently and positively associated with bone mineral content and BMD in both boys and girls (r = 0.15-0.28). Television viewing was inversely associated with hip BMD in girls (r = -0.15). The proportion of variance in bone measures explained by physical activity in linear regression models ranged from r(2) = 1.5% to 9.0%. In all of these models except total body BMD, at least 1 and often several of the physical activity variables entered as independent predictors. Activity variables most likely to enter the regression models were vigorous physical activity (as determined by accelerometry) and parental ranking of child's usual physical activity.

CONCLUSIONS

Findings indicate that there are statistically significant and, perhaps important, associations between physical activity and bone measures during early childhood, well ahead of the onset of peak bone mass. This would suggest that intervention strategies to increase physical activity in young children could contribute to optimal bone development.

Pacifier use and the occurrence of otitis media in the first year of life

PURPOSE

The purpose of this study was to assess pacifier use as a risk factor for otitis media during the first year of life.

METHODS

A volunteer cohort of 1,375 infants was recruited from eight hospital postpartum units in Iowa. Parents were asked to provide detailed information on their child's health at 6 weeks, 3, 6, 9 and 12 months of age. Questions were posed concerning occurrence of specific childhood illnesses, including otitis media, at each time point, as well as other factors.

RESULTS

Over 70% of children were reported to have experienced one or more episodes of otitis media during their first year of life, with its occurrence much more common during the second six months. Multivariate analyses using Generalized Estimating Equations assessed factors associated with otitis media during the entire 12-month period. These analyses showed that pacifier use, age, male sex, greater number of childcare days, and higher family incomes were significantly associated with occurrence of otitis media.

CONCLUSIONS

Multivariate analyses found that the occurrence of otitis media was associated with pacifier use, one of few modifiable risk factors for otitis media.

Tooth-surface progression and reversal changes in fluoridated and no-longer-fluoridated communities over a 3-year period

OBJECTIVE

To compare permanent tooth surface-specific progression/reversal changes between fluoridation-ended (F-E) and still-fluoridated (S-F) communities in British Columbia, Canada, over a 3-year period.

METHODS

D1D2MFS examinations were contrasted for 2,964 schoolchildren in 1993/94 (grades 2, 3, 8 and 9) and 1996/97 (grades 5, 6, 11 and 12). Generalized Estimating Equation (GEE) models explored the relation between progression/reversal changes and fluoridation status, age, gender, socioeconomic status, and dietary/fluoride histories.

RESULTS

Within a scenario of low levels of caries overall, few children had multiple surfaces progressing. At least one smooth surface progressed in 31.4% of subjects; at least one pit-and-fissure (PF) surface progressed in 43.1% of subjects. At least one smooth surface reverted in 89% of subjects who had reversible stages; at least one PF surface reverted in 23.8% of subjects who had reversible stages. GEE (smooth) indicated that odds ratios of progression were twice as large in the F-E site compared to the S-F site, and slightly increased in older participants and in participants exposed to more fluoride technologies. GEE (PF) also indicated that progression was slightly more common in the F-E site; more frequent snacking and lower parental educational attainment had modest associations with increased progression in PF surfaces. For the two types of surfaces, GEE models demonstrated that unerupted surfaces were less likely to progress than sound surfaces. No associations were found between reversals and independent variables.

CONCLUSION

Progressions were found to be weakly linked to socio-demographic factors; baseline surface statuses were better predictors of progression. Using the current definitions for disease transitions, F-E communities had more frequent progressions than a S-F community.

Patterns of dental caries following the cessation of water fluoridation

OBJECTIVES

To compare prevalence and incidence of caries between fluoridation-ended and still-fluoridated communities in British Columbia, Canada, from a baseline survey and after three years.

METHODS

At the baseline (1993/4 academic year) and follow-up (1996/7) surveys, children were examined at their schools. Data were collected on snacking, oral hygiene, exposure to fluoride technologies, and socio-economic level. These variables were used together with D1D2MFS indices in multiple regression models.

RESULTS

The prevalence of caries (assessed in 5,927 children, grades 2, 3, 8, 9) decreased over time in the fluoridation-ended community while remaining unchanged in the fluoridated community. While numbers of filled surfaces did not vary between surveys, sealed surfaces increased at both study sites. Caries incidence (assessed in 2,994 life-long residents, grades 5, 6, 11, 12) expressed in terms of D1D2MFS was not different between the still-fluoridating and fluoridation-ended communities. There were, however, differences in caries experienced when D1D2MFS components and surfaces at risk were investigated in detail. Regression models did not identify specific variables markedly affecting changes in the incidence of dental decay.

CONCLUSIONS

Our results suggest a complicated pattern of disease following cessation of fluoridation. Multiple sources of fluoride besides water fluoridation have made it more difficult to detect changes in the epidemiological profile of a population with generally low caries experience, and living in an affluent setting with widely accessible dental services. There are, however, subtle differences in caries and caries treatment experience between children living in fluoridated and fluoridation-ended areas.

Prevalence of enamel hypoplasia and isolated opacities in the primary dentition

PURPOSE

Enamel hypoplasia is of interest to both the clinician and the basic scientist because it may indicate an increased risk for caries and can contribute to the understanding of enamel development. The purpose of this paper is to report the prevalence of enamel hypoplasia and isolated enamel opacities in a cohort of healthy, well-nourished children in Iowa.

METHODS

The study sample consisted of 698 children examined at 4-5 years of age. Individual tooth surfaces were scored for the presence of enamel hypoplasia (EH) and isolated enamel opacities. Prevalence of EH and isolated opacities were determined by tooth type and by gender.

RESULTS

Six percent of the children examined had at least one tooth with EH; 27% had at least one tooth with isolated enamel opacities. There was no difference in the prevalence of EH between boys and girls, but significantly more boys than girls had enamel opacities.

CONCLUSIONS

The prevalence of enamel defects in this study group is comparable to that seen in other studies of normally developed children except that in this study, the primary tooth types most commonly affected with enamel hypoplasia or isolated opacities were mandibular second molars and maxillary second molars, respectively.

A prospective study of antibiotic use and associated infections in young children

This study examines antibiotic usage and associated infections in infants and young children in Iowa. Longitudinal data were collected using a cohort recruited at birth from eight hospitals in eastern Iowa. Parents of recruited children were mailed questionnaires at 6 weeks, and 3, 6, 9, 12, 16, and 20 months of age. The cumulative incidence of antibiotic use and associated infections was determined using Kaplan-Meier survival analysis. There were data on 1,368 children. Antibiotic use was common in our cohort and increased with age. Beginning at age 3 months, approximately 50% of the cohort was exposed to an antibiotic during each reporting period. Otitis media was the most common indication and was responsible for 67.3% of antibiotic use. Children were most frequently treated with amoxicillin, followed by the cephalosporins and sulphonamides. By 12 and 20 months of age 79.0% and 92.5% of the children, respectively, had been treated with at least one course of antibiotics. Children received antibiotics for a median of 43 days by 20 months of age. Males were more likely to experience any antibiotic exposure than females (hazard ratio = 1.18) and showed a trend for more days of use (P = 0.052). There was a small but significant variation in antibiotic usage in the different recruitment communities (P = 0.02).

Detecting symptoms of alcohol abuse in primary care settings

BACKGROUND

Studies on alcohol abuse are frequently based on patients who meet minimum diagnostic criteria, thus ignoring patients with individual symptoms of harmful or hazardous use. Consequently, we are unable to characterize alcohol-abusing patients with sufficient clarity to effectively focus screening for primary prevention.

OBJECTIVE

To determine the prevalence of harmful and hazardous use of alcohol, assess screening instruments for detecting alcohol abuse or dependence, and assess the impact of alcohol use on other diagnoses treated in outpatient settings.

DESIGN

Survey (cross-sectional study).

SETTING

Hospital-based outpatient clinic.

PARTICIPANTS

Three hundred randomly selected adults (aged 18 years and older).

MAIN OUTCOME MEASURE

Diagnosis of alcohol abuse or dependence based on the Diagnostic Interview Schedule (DIS).

RESULTS

About 18% met DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) criteria of abuse or dependence while almost 50% had at least one symptom of harmful or hazardous use. The T-ACE questionnaire, a modified version of the CAGE questionnaire, was the most effective screening instrument for both men and women. Selected diagnoses, personal characteristics such as family history of alcohol abuse, and self-reported patterns of alcohol use could identify patients likely to meet diagnostic criteria.

CONCLUSIONS

Many symptoms of substance use disorders are not adequately addressed in outpatient practice. Little is known about how alcohol use in varying quantities affects health care utilization and treatment of conditions commonly seen in outpatient medicine. Consequently, we lack a full appreciation of the burden of disease borne by alcohol use and have yet to achieve a universally accepted method of approaching primary and secondary prevention of alcohol-related problems.

Factors affecting dentifrice use and ingestion among a sample of U.S. preschoolers

PURPOSE

This study was performed to assess the actual amount of dentifrice used and ingested and factors associated with use/ingestion among 28 U.S. preschoolers aged 40 to 48 months.

METHODS

Using their regular dentifrice brands/flavors and small child-sized toothbrushes (Oral -B 5), the participants or their parents placed dentifrice on toothbrushes three times to assess the quantity used and its consistency. Their brushing behaviors were observed and the amounts of dentifrice ingested were indirectly measured. Afterward, the parents and children placed a "pea-sized" amount of dentifrice on their toothbrushes.

RESULTS

The participants were generally consistent in quantity applied, averaging 0.256 g (range 0.035 g-0.620 g; standard deviation 0.177 g) of dentifrice per brushing. Children, either alone or with parental assistance, placed more dentifrice than either mother or father alone (P = 0.007). The estimated mean ingested fluoride was 0.17 mg F per brushing, an average of 62% of the amount of dentifrice used (range up to 98%). Amount of ingested fluoride was positively associated (P < 0.05) with the amount of dentifrice used, and negatively associated with parental assistance in brushing. When asked to apply a pea-sized quantity, the mean quantity applied was 0.314 g (range 0.064 g-0.521 g).

CONCLUSIONS

This study further supports the use of small amounts of dentifrice in young children, because they ingest substantial proportions of dentifrice.

A comparison of sealant placement techniques and 12-month retention rates

OBJECTIVE

This study compared time required and 12-month retention for two methods of sealant placement: traditional acid-etch technique and air-abrasion technique without acid etch.

METHODS

Sealants were placed on the permanent first molars of 84 children in grades 1-4 who were randomly assigned to treatment groups. All sealants were placed in a school setting by the same clinician. Chair time required for sealant placement was recorded, and retention rates were determined for each technique 12 months after placement.

RESULTS

Mean chair time for placement of sealants on four first molars using the air-abrasion technique was significantly less than for the acid-etch technique (7:36 minutes vs 10:56 minutes). Fifty-eight children were available at 12-month follow-up; an examiner not involved in sealant placement and masked as to the technique used determined retention. Rates of complete retention for occlusal surfaces were not significantly different for the two techniques, although the rate for acid etch was higher than that for air abrasion (95% vs 87%). The complete retention rates for the acid-etch technique were significantly higher than air abrasion for buccal and distolingual surfaces. These rates were 65 percent and 58 percent, respectively, for acid etch and 6 percent and 28 percent, respectively, for air abrasion.

CONCLUSION

Although more research is needed to improve air-abrasion applications, it does not appear that air abrasion without acid etching offers a significant advantage over traditional sealant placement methods and, in fact, appears to be inferior to the acid-etch technique for use in public health settings.

Factors related to decisions to extract or retain at-risk teeth

OBJECTIVES

Decisions to extract a tooth may be among the most critical in dentistry. The aim of this study was to prospectively investigate both clinical and nonclinical factors related to decisions to extract or retain teeth in private general dental practice.

METHODS

A convenience sample of 196 Iowa dentists in private general dental practice reported on 549 cases where decisions were made to extract or retain teeth as they occurred in their practices during a one-month period in May 1997. Bivariate and multivariate analyses were used to identify factors that differentiated between cases where a tooth (or teeth) was extracted and cases where an at-risk tooth was retained.

RESULTS

Of the 549 cases, 67 percent involved extraction, while the remainder involved alternatives to extraction. In comparing extraction cases to alternative treatment cases, we excluded 150 extraction cases because dentists reported that no alternative to extraction was available. Using Generalized Estimating Equations (GEE), we identified cost of treatment, presence of tooth mobility, poor prognosis of alternative treatment, and presence of gross caries as significant factors associated with extraction, while previous treatment of the tooth and concerns with patients' health were significantly associated with alternatives to extraction.

CONCLUSIONS

For teeth at risk for extraction, cost, substantial periodontal disease, and several clinical factors were predictive of extraction.

Non-nutritive sucking behaviors in preschool children: a longitudinal study

PURPOSE

Prolonged duration of non-nutritive sucking behaviors may have consequences in regard to the developing orofacial structures and occlusion. Little is known as to why some children have prolonged sucking habits beyond the first 2 to 3 years of life. This paper reports on non-nutritive sucking patterns among a large cohort of healthy children from birth to 36 months of age and older, and identifies factors predictive of prolonged non-nutritive sucking habits.

METHODS

Over 600 children were followed from birth to at least 36 months of age using mailed questionnaires sent when children reached the ages of 6 weeks, and 3, 6, 9, 12, 16, and 24 months, and then yearly thereafter. Parents answered questions concerning non-nutritive sucking behaviors including use of pacifier and digit sucking. The study categorized children who maintained habits to 36 months of age or older as having prolonged habits, and using multivariate analyses, compared them to children without prolonged habits on various sociodemographic variables.

RESULTS

The study found that for over 20% of the children, a non-nutritive sucking habit was prolonged to 36 months of age or older. Factors associated with prolonged sucking habits included older maternal age, higher maternal education level, and having no older siblings.

CONCLUSIONS

Identifying factors related to prolonged non-nutritive sucking habits may be important in developing and targeting recommendations regarding such behaviors in an effort to prevent malocclusions that result from prolonged sucking habits.

Total fluoride intake and implications for dietary fluoride supplementation

This paper reviews the history and validity of recommended "optimal" levels of systemic fluoride intake and the available information on levels of fluoride intake in young children from foods and beverages (including water), dentifrices, dietary fluoride supplements, mouthrinses, and gels. Most of the studies emphasize the substantial variation in ingestion among individuals. Often, a substantial proportion of individuals received fluoride well beyond the mean exposure reported in the study. Limitations in the existing data make it difficult to determine the total distribution of fluoride intake from all sources. Therefore, hypothetical combinations of possible daily fluoride intake from the three main sources (diet, dentifrices, and supplements) are presented for those aged 6, 12, 24, and 36 months, with associated mean intake per kg body weight. Findings suggest that some children exceed the "optimal" level of fluoride intake from single sources alone, while others can from a combination of sources. Moreover, if current recommended "optimal" levels, which have been derived on an empirical basis, are actually lower than what has been quoted in the literature, then more children could be ingesting excessive amounts of fluoride, which could increase their risk of developing objectionable dental fluorosis. The variation and complexity of fluoride ingestion from all sources should be considered in the evaluation of recommendations for use of dietary fluoride supplements.

Assessing fluoride levels of carbonated soft drinks

BACKGROUND

Dental fluorosis occurs as a result of excessive total fluoride intake during tooth development. Some children may receive substantial intake from soft drinks, but few studies have reported fluoride levels in soft drinks. The authors examined the fluoride concentrations of 332 soft drinks.

METHODS

Soft drinks were purchased from Iowa grocery stores. To identify production sites, the authors recorded product details and batch numbers. After decarbonating the drinks, the authors assayed samples for fluoride content using a fluoride ion-specific electrode, and reported the results in parts per million, or ppm, using appropriate standards and duplicate assessments. Descriptive statistics were used to summarize the findings.

RESULTS

The fluoride levels of the products ranged from 0.02 to 1.28 ppm, with a mean level of 0.72 ppm. Fluoride levels exceeded 0.60 ppm for 71 percent of the products. Results varied substantially by production site, even within the same company and for the same product. There were no substantial differences between flavors or between diet and regular soft drinks.

CONCLUSIONS

The majority of soft drinks had fluoride levels exceeding 0.60 ppm. Variation in fluoride levels probably is due largely to the different water sources used in production.

CLINICAL IMPLICATIONS

With no fluoride levels marked on the soft drink products or easily available from the manufacturers, it is not possible for clinicians or consumers to directly estimate fluoride ingestion from carbonated beverages. Therefore, to reduce the risk of dental fluorosis, dental and medical practitioners should be cautious about prescribing dietary fluoride supplements to preschool-aged children in nonfluoridated areas who consume large quantities of carbonated soft drinks.

Systemic fluoride. Sources, amounts, and effects of ingestion

Fluoride may be ingested from a variety of sources, including many foods and beverages. Fluoride intake varies greatly among individuals and is dependent on dietary constituents and use of fluoride products. Although ingestion of toxic amounts of fluoride is rare, the prevalence of dental fluorosis has increased in North America, suggesting that the levels of fluoride ingestion need to be closely monitored. Care should be taken to avoid excessive ingestion of fluoride dentifrice by preschool-aged children by placement of a small, pea-sized quantity on the tooth-brush. Dietary fluoride supplements should be considered a targeted, preventive procedure only for those at elevated caries risk, and before prescribing them, careful consideration should be given to other fluoride sources, including home and child-care water supplies, foods, and beverages.

A review of fluoride dentifrice related to dental fluorosis

Introduced to the commercial market 40 years ago, fluoride dentifrice now accounts for nearly all dentifrice purchased in the United States. During this same time, the prevalence and severity of dental caries has declined while dental fluorosis prevalence has increased. While the caries decline can be largely attributed to widespread fluoride dentifrice use, as well as many other sources of fluoride, several recent studies have attributed much of the increase in fluorosis prevalence to early use of fluoride dentifrice. This paper reviews these studies, as well as the efficacy of fluoride dentifrices with lower fluoride concentrations. Finally, recommendations regarding fluoride dentifrice to maintain caries prevention and reduce the risk of dental fluorosis are presented.

Patterns of dietary fluoride supplement use during infancy

OBJECTIVES

This paper reports on patterns of dietary fluoride supplement use during infancy.

METHODS

Data were collected by mail for a birth cohort (n = 1,072) studied at 6 weeks and 3, 6, 9, and 12 months of age.

RESULTS

Percentages using supplements were 13.7 at 6 weeks, 13.4 at 3 months, 16.5 at 6 months, 13.0 at 9 months, and 12.1 at 12 months. Among those receiving supplements, mean proportions of weeks that supplements were received during the different time periods varied from 0.59 to 0.80. Number of days per week receiving supplements averaged 4.8 to 5.0. Mean fluoride dosages when supplements were received were 0.22 mg to 0.24 mg. Estimated average daily fluoride ingestion per day (among those receiving supplements during that time period and factoring in those days and weeks that supplements were not received) was 0.11 mg at 6 weeks, 0.15 mg at 3 months, 0.12 mg at 6 months, 0.11 mg at 9 months, and 0.14 mg at 12 months. Among the subset of 129 children with complete data at all time points who used supplements sometime during their first year of life, mean annual daily supplement dosage was 0.07 mg fluoride, with 75 percent having less than or equal to 0.10 mg. Those infants with mothers and fathers with more education were more likely to receive supplements.

CONCLUSIONS

Group average use of fluoride supplements was fairly consistent over the 12 months; however, individual patterns varied substantially. Estimated actual mean daily fluoride intake when including days that supplements were not received was substantially less than the recommended 0.25 mg per day.

Fluorosis of the primary dentition: what does it mean for permanent teeth?

BACKGROUND

The prevalence of fluorosis of the permanent teeth has increased during the past few decades in the United States and Canada. However, primary-tooth fluorosis has been largely overlooked, because it is often difficult to recognize. This article describes primary-tooth fluorosis, both as characterized in the literature and as seen clinically.

METHODS

The authors review and summarize previous studies of primary-tooth fluorosis and discuss its etiology. In addition, the authors describe the condition, based on findings from the literature, and their own experiences in characterizing it as part of a longitudinal investigation of fluoride exposures, dental fluorosis and dental caries.

RESULTS

Several studies indicate that primary-tooth fluorosis can be prevalent and severe in areas of very high water fluoride concentrations. In these areas, primary-tooth fluorosis is likely the result of both pre- and postnatal exposures. Studies have documented that primary-tooth fluorosis does occur in areas with optimal or suboptimal water fluoride concentrations, and that in these settings primary-tooth fluorosis is most likely caused by postnatal exposures and is seen most commonly in the primary molars. Primary-tooth fluorosis, however, is often more difficult to identify than fluorosis in permanent teeth, and clinicians may be unfamiliar with its characteristics and may not recognize its somewhat subtle appearance.

CONCLUSIONS

Primary-tooth fluorosis may be related to occurrence of fluorosis in the permanent dentition, so that its recognition by the clinician should raise awareness of possible increased risk for the permanent dentition.

CLINICAL IMPLICATIONS

The detection of primary-tooth fluorosis in a young child should prompt the clinician to carefully review the child's past fluoride exposures and current fluoride practices, as well as those of any younger siblings.

The accuracy of tooth loss data collected by nurses

This paper reports on the accuracy of tooth counts conducted in 22 subjects by 10 trained nurses as part of a large longitudinal study of a pharmacological agent. These nurses participated in a training course consisting of seminars, discussion, demonstrations, and practice examinations. Each of the nurses then counted the teeth of 22 subjects and recorded their findings independently. The counts of the nurses were compared with those of the dentists to assess the accuracy of the nurses' counts. We found that nurses and dentists were in perfect agreement for 86% of the patient counts conducted. Individual nurses' levels of agreement with dentists ranged from 73% to 100%, with pairwise kappa statistic values ranging from 0.70 to 1.00. In addition, both Pearson correlation and interclass correlation measures exceeded 0.98 for every comparison of dentist and nurse counts. The results of this study suggest that training nondental health care workers may be an accurate and low-cost way of obtaining tooth loss data and other oral health measures, particularly when oral health data are collected as part of larger, multi-disciplinary studies.