Disability days in Canada associated with dental problems: a pilot study.

OBJECTIVE: The aim of this study was to explore disability days, or bed days and cut-down days, associated with dental problems in Canada. METHODS: Data were collected through a national telephone interview survey of 1005 Canadians aged 18 years and over using random digit dialling. Participants were asked to enumerate the number of disability days associated with dental problems in the previous 2-week period. Descriptive and bivariate logistic regression analyses were undertaken. RESULTS: In the previous 2-week period, 33 people, or 3.3% of the sample, reported spending a day in bed because of a dental problem. Of these, 22 people also reported having to cut down on their normal activity because of the dental problem. It appears that younger age groups, those with the lowest incomes, college educations, no dental insurance, oral pain and a history of visiting a hospital emergency room for a dental problem, were all more likely to report a dental disability day. CONCLUSIONS: These data demonstrate the potential economic impacts of dental problems in Canada, yet they must be interpreted with caution because of the very low prevalence of the main outcome measure, the potential for selection bias and the relative inconsistency with existing historical estimates.

Rm62, a DEAD-box RNA helicase, complexes with DSP1 in Drosophila embryos.

Two main classes of proteins, Polycomb group (PcG) and Trithorax group (TrxG), play a key role in the regulation of homeotic genes. These proteins act in multimeric complexes to remodel chromatin. A third class of proteins named Enhancers of Trithorax and Polycomb (ETP) modulates the activity of TrxG and PcG, but their role remains largely unknown. We previously identified an HMGB-like protein, DSP1 (Dorsal Switch Protein 1), which was classified as an ETP. Preliminary studies have revealed that DSP1 is involved in multimeric complexes. Here we identify a DEAD-box RNA helicase, Rm62, as partner of DSP1 in a 250-kDa complex. Coimmunoprecipitation assays performed on embryo extracts indicate that DSP1 and Rm62 are associated in 3- to 12-h embryos. Furthermore, DSP1 and Rm62 colocalize on polytene chromosomes. Consistent with these results, a mutation in Rm62 enhances a null mutation of dsp1 and also mutations of trxG or PcG, suggesting that Rm62 has characteristics of an ETP. We show here for the first time that an RNA helicase is involved in the maintenance of homeotic genes.

Dental health state utility values associated with tooth loss in two contrasting cultures.

The study aimed to assess the value placed on oral health states by measuring the utility of mouths in which teeth had been lost and to explore variations in utility values within and between two contrasting cultures, UK and Iran. One hundred and fifty eight patients, 84 from UK and 74 from Iran, were recruited from clinics at University-based faculties of dentistry. All had experienced tooth loss and had restored or unrestored dental spaces. They were presented with 19 different scenarios of mouths with missing teeth. Fourteen involved the loss of one tooth and five involved shortened dental arches (SDAs) with varying numbers of missing posterior teeth. Each written description was accompanied by a verbal explanation and digital pictures of mouth models. Participants were asked to indicate on a standardized Visual Analogue Scale how they would value the health of their mouth if they had lost the tooth/teeth described and the resulting space was left unrestored. With a utility value of 0.0 representing the worst possible health state for a mouth and 1.0 representing the best, the mouth with the upper central incisor missing attracted the lowest utility value in both samples (UK = 0.16; Iran = 0.06), while the one with a missing upper second molar the highest utility values (0.42, 0.39 respectively). In both countries the utility value increased as the tooth in the scenario moved from the anterior towards the posterior aspect of the mouth. There were significant differences in utility values between UK and Iranian samples for four scenarios all involving the loss of anterior teeth. These differences remained after controlling for gender, age and the state of the dentition. With respect to the SDA scenarios, a mouth with a SDA with only the second molar teeth missing in all quadrants attracted the highest utility values, while a mouth with an extreme SDA with both missing molar and premolar teeth in all quadrants attracted the lowest utility values. The study provided further evidence of the validity of the scaling approach to utility measurement in mouths with missing teeth. Some cross-cultural variations in values were observed but these should be viewed with due caution because the magnitude of the differences was small.

Epidemiological evaluation of short-form versions of the Child Perception Questionnaire.

The objective of the study was to compare the performance of four short-form versions of the Child Perceptions Questionnaire (CPQ(11-14)) with that of the long-form version in a random population sample of 12- and 13-yr-old children from New Zealand in order to determine which short-form version was the most valid. Children (n = 430, participation rate 74.1%) completed the 37-item CPQ(11-14). Two separate 8- and 16-item short-form versions were previously developed using (a) item impact and (b) regression methods. The four different short-form scales were compared with the full CPQ(11-14) on their construct validity. The children were examined for malocclusion (using the Dental Aesthetic Index) and for dental caries by a single examiner (L.F.P.). All short-form versions revealed substantial variability in overall oral health-related quality of life (OHRQoL). Cronbach's alpha ranged from 0.73 (Regression Short Form [RSF]-8) to 0.86 (RSF-16). For all short-form versions, mean scores were positively associated with self-rated oral health and overall wellbeing; associations with the latter were stronger. All short-form versions detected OHRQoL gradients, as hypothesized, across ascending categories of caries and malocclusion. These findings suggest that the short-form versions of the CPQ(11-14) all show acceptable properties, but that the 16-item versions perform better (and are essentially equivalent); however, the stronger theoretical underpinning of the item-impact-derived 16-item short-form version suggests that it shows the most promise.

Comparison of two methods in deriving a short version of oral health-related quality of life measure.

OBJECTIVE: To compare two methods of developing short forms of the Malaysian Oral Health Impact Profile (OHIP-M) measure. METHOD: Cross sectional data obtained using the long form of the OHIP-M was used to produce two types of OHIP-M short forms, derived using two different methods; namely regression and item frequency methods. The short version derived using a regression method is known as Reg-SOHIP(M) and that derived using a frequency method is known as Freq-SOHIP(M). Both short forms contained 14 items. These two forms were then compared in terms of their content, scores, reliability, validity and the ability to distinguish between groups. RESULTS: Out of 14 items, only four were in common. The form derived from the frequency method contained more high prevalence items and higher scores than the form derived from the regression method. Both methods produced a reliable and valid measure. However, the frequency method produced a measure, which was slightly better in terms of distinguishing between groups. CONCLUSION: Regardless of the method used to produce the measures, both forms performed equally well when tested for their cross-sectional psychometric properties.

Canadian dental students' perceptions of stress and social support.

This study explored the relationship between dental school stress and social support reported by undergraduate students in a Canadian dental school. Students completed questionnaires comprised of Dental Environment Scale stress items, social support measures evaluating perceived contact and two proxy measures of social support (marital status and living arrangement). Sixty-two per cent of undergraduate students in all four academic years participated in the study conducted in March--April 2005. Second-year students living with parents had significantly higher adjusted total stress scores (P < 0.001), whilst fourth-year students living with roommates had significantly lower total adjusted stress scores (P = 0.008). Social support systems utilised by students included teacher, parental, student and relationship support. Students who received more support from teachers and from students inside and outside dental school had lower adjusted total stress scores. Multiple regression analysis assessing the effect of social support on total adjusted stress scores identified two significant variables after adjustment: second-year students living with parents (P < 0.001) and low teacher support (P = 0.032). This study identified social support and proxy measures as significant predictors of dental school stress in Canadian dental students. Further studies are needed to elucidate the role of social support and proxy measures as potential dental school stress alleviators.

Cross-cultural adaptation of the Oral Health Impact Profile (OHIP) for the Malaysian adult population.

OBJECTIVE: The aim of this project was to develop an oral health related-quality of life measure for the Malaysian adult population aged 18 and above by the cross-cultural adaption the Oral Health Impact Profile (OHIP). METHOD: The adaptation of the OHIP was based on the framework proposed by Herdman et al (1998). The OHIP was translated into the Malay language using a forward-backward translation technique. Thirty-six patients were interviewed to assess the conceptual equivalence and relevancy of each item. Based on the translation process and interview results a Malaysian version of the OHIP questionnaire was produced that contained 45 items. It was designated as the OHIP(M). This questionnaire was pre-tested on 20 patients to assess its face validity. A short 14-item version of the questionnaire was completed by 171 patients to assess the suitability of the Likert-type response format. Field-testing was conducted in order to assess the suitability of two modes of administration (mail and interview) and to establish the psychometric properties of the adapted measure. RESULTS: The pre-testing revealed that the OHIP(M) has good face validity. It was found that the five-point frequency Likert scale could be used for the Malaysian population. The OHIP(M) was reliable, where the scale Cronbach's alpha was 0.95 and the ICC value for test-retest reliability was 0.79. Three out four construct validity hypotheses tested were confirmed. OHIP(M) works equally well as the English version. CONCLUSION: OHIP(M) was found to be reliable and valid regardless of the mode of administration. However, this study only provides initial evidence for the reliability and validity of the measure. Further study is recommended to collect more evidence to support these results.

HMG boxes of DSP1 protein interact with the rel homology domain of transcription factors.

Formation of the dorsoventral axis in Drosophila melanogaster is mediated through control of the expression of several genes by the morphogen Dorsal. In the ventral part of the embryo Dorsal activates twist and represses zen amongst others. Recently, several proteins have been shown to assist Dorsal in the repression of zen, one of which is DSP1, a HMG box protein that was isolated as a putative co-repressor of Dorsal. In this report we used a DSP1 null mutant to ascertain in vivo the involvement of DSP1 in Dorsal-mediated repression of zen but not in the activation of twist. We show that Dorsal has the ability to interact with DSP1 in vitro as well as with rat HMG1. Using truncated versions of the proteins we located the domains of interaction as being the HMG boxes for DSP1 and HMG1 and the Rel domain for Dorsal. Finally, studies of the zen DNA binding properties of Dorsal and another related Rel protein (Gambif1 from Anopheles gambiae) revealed that their DNA binding affinities were increased in the presence of DSP1 and HMG1.

Associations between xerostomia and health status indicators in the elderly.

AIMS: This study investigated the associations between xerostomia (dry mouth) (low, moderate and high) with other categorical variables (e.g. demographic and health status indicators). This paper aims to report on the severity of xerostomia in the elderly population and investigate the relationship with other aspects of perceived health. METHOD: Data were obtained from a cross-sectional survey of 225 elderly people from a large multilevel geriatric care centre. The centre consists of three levels of care: an apartment building in which residents live more or less independently, a home for the aged, and a chronic care hospital. Participants in the study were recruited when they attended the dental care facility. Data were collected by means of a personal interview conducted either at the dental care facility or the participant's residence. RESULTS: The mean age was 83 years. Most were females (72%) and almost all (99%) reported one or more chronic medical conditions; 88% had physical disabilities. Xerostomia was recorded on a seven-point scale. Scores were categorised as low, medium or high and the proportions were 49.3%, 30.3% and 20.4% respectively Bivariate analysis showed no association between dry mouth and sex, age, general health change or life satisfaction. However, when the high xerostomia group was separated out and odds ratios calculated they were 2.3 to 4.9 times more likely to experience a negative impact on health than the low group. Xerostomia did not have a significant impact on chewing capacity, morale or stress, although it contributed to the variability of the oral health-related quality of life measures. It was the only variable with a significant effect (OR 2.55) for the Oral Health Impact Profile-14 and displayed a higher odds ratio (2.76) for the Geriatric Oral Health Assessment Index. Self-reported xerostomia in the elderly population can be categorised into a severity scale. Those suffering most from xerostomia are more likely to experience a negative impact on general health. CONCLUSION: The key finding in this study is that xerostomia has a significant and negative impact on the quality of life of elderly individuals, though oral function may be less affected.

The impact of oral conditions on the quality of life of the Malaysian adult population: preliminary results.

The aim of this paper is to describe the impact of oral conditions on the quality of life of the adult population of Malaysia. The adapted Malaysian Oral Health Impact Profile (L-OHIP-M) questionnaire was used. A total of two hundred and twenty respondents completed the L-OHIP(M). Overall, slightly more than 50% of the sample had at least one impact reported as either "very often" or "often". The younger age group, Indian ethnic and those who had tertiary education reported more impacts. The preliminary results revealed that a substantial proportion of the sample included in this study experienced frequent psychosocial impacts associated with oral conditions.

HMG1 protein inhibits the translesion synthesis of the major DNA cisplatin adduct by cell extracts.

When situated in a fork-like synthetic DNA replication substrate, the 1,2-intrastrand crosslink at the d(GpG) site, the most frequent adduct formed in the reaction between DNA and the anticancer drug cisplatin (cis-diamminedichloroplatinum (II)), is efficiently bypassed by eukaryotic cell extracts. We show here that the rat high-mobility-group protein 1 (HMG1) binds preferentially to the platinated fork-like synthetic DNA and inhibits the translesion synthesis. The same protein, but without the acidic tail, inhibits also the translesion synthesis. These results suggest that HMG proteins might contribute to the sensitivity of cells to cisplatin by directly affecting DNA replication.

Interaction between cisplatin-modified DNA and the HMG boxes of HMG 1: DNase I footprinting and circular dichroism.

The interactions between the two boxes A and B of HMG 1 and cis-diamminedichloroplatinum(II)-modified DNA containing a single intrastrand cross-link at the d(GpG) site were studied by DNase I footprinting and circular dichroism. The DNAase I cleavage patterns of the HMG box-platinated DNA complexes are identical, the two boxes inhibiting the DNase I cutting over at least 15 and 12 nucleotide residues in the platinated strand and the complementary strand, respectively. As judged by circular dichroism, the two boxes have the same alpha-helical content (56%) and they induce the same conformational changes in the platinated DNA.

DSP1, an HMG-like protein, is involved in the regulation of homeotic genes.

The Drosophila dsp1 gene, which encodes an HMG-like protein, was originally identified in a screen for corepressors of Dorsal. Here we report that loss of dsp1 function causes homeotic transformations resembling those associated with loss of function in the homeotic genes Sex combs reduced (Scr), Ultrabithorax (Ubx), and Abdominal-B. The expression pattern of Scr is altered in dsp1 mutant imaginal discs, indicating that dsp1 is required for normal expression of this gene. Genetic interaction studies reveal that a null allele of dsp1 enhances trithorax-group gene (trx-G) mutations and partially suppresses Polycomb-group gene (Pc-G) mutations. On the contrary, overexpression of dsp1 induces an enhancement of the transformation of wings into halteres and of the extra sex comb phenotype of Pc. In addition, dsp1 male mutants exhibit a mild transformation of A4 into A5. Comparison of the chromatin structure at the Mcp locus in wild-type and dsp1 mutant embryos reveals that the 300-bp DNase I hypersensitive region is absent in a dsp1 mutant context. We propose that DSP1 protein is a chromatin remodeling factor, acting as a trx-G or a Pc-G protein depending on the considered function.

Validation of the Child Perceptions Questionnaire (CPQ 11-14).

While the use of adult oral-health-related quality-of-life (OHRQoL) measures in supplementing clinical indicators has increased, that for children has lagged behind, because of the difficulties of developing and validating such measures for children. This study examined the construct validity of the Child Perceptions Questionnaire (CPQ(11-14)) in a random sample of 12- and 13-year-old New Zealanders. It was hypothesized that children with more severe malocclusions or greater caries experience would have higher overall (and subscale domain) CPQ(11-14) scores. Children (N = 430) completed the CPQ(11-14) and were examined for malocclusion (Dental Aesthetic Index) and dental caries. There was a distinct gradient in mean CPQ(11-14) scores by malocclusion severity, but there were differences across the four subscales. Children in the worst 25% of the DMFS distribution had higher CPQ(11-14) scores overall and for each of the 4 subscales. The construct validity of the CPQ(11-14) appears to be acceptable.

An evaluation of the Child Perceptions Questionnaire in the UK.

OBJECTIVE: To assess the reliability and validity of the Child Perceptions Questionnaire (CPQ11-14), an oral health related quality of life measure for 11-14 year old children, for use in the UK. BASIC RESEARCH DESIGN: Cross-sectional questionnaire and clinical analytical study. CLINICAL SETTING: Orthodontic and paediatric dentistry clinics at a dental hospital and one general dental practice. PARTICIPANTS: Eighty-nine children between 11 and 14 years of age attending for an examination. MAIN OUTCOMES MEASURES: The children were invited to complete the CPQ11-14, global oral health and impact on life overall ratings. Clinical data on caries status, malocclusion and presence of dental opacities and gingivitis were collected. CPQ11-14 was summarised as the total score (sum of the item codes) and the number of impacts reported often or every day. RESULTS: The Cronbach's alpha for the total scale was 0.87 and ranged from 0.59 to 0.83 for the subscales indicating acceptable internal consistency. The intraclass correlation coefficient on repeated application of the measure was 0.83 (95% CI = 0.76-0.90) suggesting almost perfect agreement. Summary measures of CPQ11-14 correlated with the global oral health rating indicating acceptable criterion validity. Impact on life overall was related to all summary measures of CPQ11-14. Number of impacts correlated with the total number of missing teeth and missing teeth due to caries. No other relationships between clinical and CPQ11-14 data were apparent. CONCLUSION: The CPQ11-14 shows acceptable reliability, criterion and construct validity in relation to life overall. Relationships with clinical data were more tenuous. If this measure is to be used to compare the impacts of oral diseases in similar settings in the UK a large sample will be required.

Need and demand for sedation or general anesthesia in dentistry: a national survey of the Canadian population.

The aim of this study was to assess the need and demand for sedation or general anesthesia (GA) for dentistry in the Canadian adult population. A national telephone survey of 1101 Canadians found that 9.8% were somewhat afraid of dental treatment, with another 5.5% having a high level of fear. Fear or anxiety was the reason why 7.6% had ever missed, cancelled, or avoided a dental appointment. Of those with high fear, 49.2% had avoided a dental appointment at some point because of fear or anxiety as opposed to only 5.2% from the no or low fear group. Regarding demand, 12.4% were definitely interested in sedation or GA for their dentistry and 42.3% were interested depending on cost. Of those with high fear, 31.1% were definitely interested, with 54.1% interested depending on cost. In a hypothetical situation where endodontics was required because of a severe toothache, 12.7% reported high fear. This decreased to 5.4% if sedation or GA were available. For this procedure, 20.4% were definitely interested in sedation or GA, and another 46.1% were interested depending on cost. The prevalence of, and preference for, sedation or GA was assessed for specific dental procedures. The proportion of the population with a preference for sedation or GA was 7.2% for cleaning, 18% for fillings or crowns, 54.7% for endodontics, 68.2% for periodontal surgery, and 46.5% for extraction. For each procedure, the proportion expressing a preference for sedation or GA was significantly greater than the proportion having received treatment with sedation or GA (P < 0.001). In conclusion, this study demonstrates that there is significant need and demand for sedation and GA in the Canadian adult population.

The Drosophila DSP1 gene encoding an HMG 1-like protein: genomic organization, evolutionary conservation and expression.

The gene that encodes the dorsal switch protein (DSP1) has been isolated from a Drosophila melanogaster cosmid library. It is organized into seven exons and six introns. The relative position of the introns within the region coding for the high mobility group (HMG) domains are identical to those of vertebrate HMG 1/2 genes. The close similarity between DSP1 and HMG 1/2 genes strongly suggests that these genes derived from a common ancestral gene. DSP1 encodes, at least, two distinct mRNAs that differ in the length of their 5'-untranslated region and coding sequence. Detailed sequence analysis shows that alternative splicing of precursor mRNA gives rise to the two isoform mRNAs found in Drosophila cells.

Detection of minor adducts in cisplatin-modified DNA by transcription footprinting.

Two DNA restriction fragments containing either a d(GC)5 or a d(TTGCTTGATTAGTTGTGTT) insert were subjected to reaction with cis-diamminedichloroplatinum(II) and were then used as templates for RNA synthesis by T7 RNA polymerase. Within the d(GC)5 insert, interstrand cross-links are preferentially formed. Within the second insert, the reactivity order of the potential binding sites is d(ApG) > d(GpC/GpC) = d(GpA) > d(GpTpG). In the presence of cyanide ions, the adducts are much less stable at the d(GpA) sites than at the d(GpCpG) sites, in double-stranded DNA.

Detection of antibody secreting hybridomas with diazobenzyloxymethyl paper: an easy, sensitive and versatile assay.

A sensitive and universal assay for the detection of monoclonal antibodies is described. One microliter of each hybrid cell supernatant is transferred to activated diazobenzyloxymethyl paper and, after coating the uncovered activated sites by incubation with bovine serum albumin, the paper is dipped in a solution of 125I-labeled antigen. After incubation to allow for fixation of antigen to antibody present in the supernatants, the paper is rinsed and autoradiographed. As many as 96 wells can be tested on one paper and more than 20 papers can be treated in 1 day (approximately 2000 wells). The sensitivity and reliability of the method were tested with monoclonal antibodies against a subunit of scorpion (Androctonus australis) hemocyanin. Unlike other immunobinding assays the test depends only on antigen-antibody interaction and not on class or subclass of immunoglobulin. It is suitable for a variety of hybridomas.

Health outcomes of oral disorders.

While there is a substantial body of data on patterns of dental disease in both adult and child populations, there is relatively little information concerning the consequences of oral disorders for well-being and the quality of life. In addition, dentistry lacks measures of health outcomes for use in dental health surveys and clinical trials. However, interest in this area is growing and a number of oral-condition specific health status measures have been developed over the last 10 years. The most sophisticated is the Oral Health Impact Profile (OHIP) which is being developed and tested by research teams in Australia, Canada and the US. This consists of 49 items organized into seven sub-scales which address the way in which oral conditions compromise functioning and social and psychological well-being. A study of older adults in Canada which used OHIP found that it had good measurement properties. Nevertheless, there was only a weak association between scores on this measure and clinical indicators of oral disease. Further analysis revealed that social factors were as important as clinical factors in explaining the health outcome of oral disorders. This finding is consistent with contemporary concepts of health and provides some evidence to support the view that the social context in which we live is important in shaping responses to disease and the experience of health and illness.