Phobic anxiety in 11 nations. Part I: Dimensional constancy of the five-factor model

The Fear Survey Schedule-III (FSS-III) was administered to a total of 5491 students in Australia, East Germany, Great Britain, Greece, Guatemala, Hungary, Italy, Japan, Spain, Sweden, and Venezuela, and submitted to the multiple group method of confirmatory analysis (MGM) in order to determine the cross-national dimensional constancy of the five-factor model of self-assessed fears originally established in Dutch, British, and Canadian samples. The model comprises fears of bodily injury-illness-death, agoraphobic fears, social fears, fears of sexual and aggressive scenes, and harmless animals fears. Close correspondence between the factors was demonstrated across national samples. In each country, the corresponding scales were internally consistent, were intercorrelated at magnitudes comparable to those yielded in the original samples, and yielded (in 93% of the total number of 55 comparisons) sex differences in line with the usual finding (higher scores for females). In each country, the relatively largest sex differences were obtained on harmless animals fears. The organization of self-assessed fears is sufficiently similar across nations to warrant the use of the same weight matrix (scoring key) for the FSS-III in the different countries and to make cross-national comparisons feasible. This opens the way to further studies that attempt to predict (on an a priori basis) cross-national variations in fear levels with dimensions of national cultures.

Changes in levels of dental anxiety as a function of dental experience

From the literature, it is increasingly apparent that dentally anxious individuals are not a homogeneous group and that the development and maintenance of dental anxiety are complex phenomena. In this study, individuals who had avoided dental treatment in the past due to fear but were no longer fearful were compared with others who had avoided and were still fearful on a number of demographic, experiential, and attitudinal variables under the assumption that avoidance is likely to prevent the emotional processing of dental anxiety. The groups differed markedly in their experience of dentistry; anxious avoiders were more likely to have experienced more invasive and less noninvasive dental treatment; they feared pain more and were more negative about dentistry than those whose anxiety had remitted. In addition, the remitted avoiders were less likely to claim frightening or embarrassing dental experiences as well as being less reactive to these experiences than the others.

Age of onset of dental anxiety

Little attention has been given to the issue of the age of onset of dental anxiety, even though it may have a bearing on the origins of this type of fear. This study aimed to identify the age of onset of dental anxiety and to identify differences by age of onset with respect to potential etiological factors, such as negative dental experiences, family history of dental anxiety, and general psychological states. Data were collected by means of two mail surveys of a random sample of the adult population. Of 1420 subjects returning questionnaires, 16.4% were dentally anxious. Half, 50.9%, reported onset in childhood, 22.0% in adolescence, and 27.1% in adulthood. Logistic regression analyses indicated that negative dental experiences were predictive of dental fear regardless of age of onset. A family history of dental anxiety was predictive of child onset only. Adolescent-onset subjects were characterized by trait anxiety and adult-onset subjects by multiple severe fears and symptoms indicative of psychiatric problems. The three groups were similar in terms of their physiological, cognitive, and behavioral responses to dental treatment. However, adolescent- and adult-onset subjects were more hostile toward and less trusting of dentists. These results indicate that child-onset subjects were more likely to fall into the exogenous etiological category suggested by Weiner and Sheehan (1990), while adult-onset subjects were more likely to fall into the endogenous category.

Diagnostic categories of dental anxiety: a population-based study

This study aimed to use a population-based sample to assess the psychological validity of the Seattle system for diagnosing dentally anxious individuals. This system consists of four diagnostic types in which such individuals are categorized according to the main source of their fear regarding dental treatment. Subjects were 1420 randomly selected adults aged 18 years and over who took part in a two-stage mail survey. The questionnaires contained measures of dental anxiety and standardized measures of general anxiety and fearfulness. Allocation to the Seattle categories was based on responses to four diagnostic items. Overall, 16.4% of the sample were dentally anxious. Their distribution across the four Seattle types was as follows: type I (simple conditioned phobia)--49.6%; type II (fear of catastrophe)--7.8%; type III (generalized anxiety)--19.4% and type IV (distrust of dentists)--9.9%. The remaining 13.3% could not be categorized. Judging by their scores on measures of dental anxiety, these subjects were borderline cases. Scores on the measures of anxiety and fearfulness indicated that the diagnostic system was valid and identified sub-groups of the dentally anxious population which were internally consistent. However, all subjects indicated extreme fear of dental treatment and were broadly similar in terms of their cognitive and behavioral responses to dental care. Of particular interest was the distribution of diagnoses according to age. Younger subjects were more likely to be categorized as type I, while older subjects were more likely to be categorized as type III. Overall, the results indicate that dental anxiety is a complex fear with a number of components.

Characteristics of early unpleasant dental experiences

There is evidence in the literature that dentally anxious individuals are not a homogeneous group. Various ways of categorizing them have been suggested. These categories have stemmed primarily from clinical experience or psychiatric diagnoses. In addition, Reiss' (1987, 1991) expectancy theory of fear, anxiety and panic appears to fit some of the etiological data. At the simplest level, it is suggested that dental anxiety may result from direct conditioning experiences or from a constitutional vulnerability to develop anxiety-based problems. Taking conditioning theory and Reiss's model as a basis, it was predicted dental events deemed unpleasant would fall under four categories: (a) events relating to dental specific procedures and stimuli, (b) events relating to injuries, (c) events relating to emotional responses and (d) events relating to dental personnel behavior. In addition, it was predicted that individuals who would report high-anxiety sensitivity as measured by the anxiety sensitivity index (ASI) would be more likely to perceive unpleasant incidents relating to injuries, emotional responses and dental personnel behavior than individuals with low-anxiety sensitivity. On the other hand, everyone would be affected by incidents relating to specific dental procedures and stimuli. The participants were 510 university students who were surveyed during class time. The first prediction was supported but the second one was only partially supported, in that, participants who obtained high scores on the ASI differed from the others only regarding injuries.

Determinants of positive and negative attitudes toward dentistry

Previous studies have primarily investigated the determinants of negative attitudes toward dentistry. Little is known about the reasons for positive attitudes. Using a group of university students who were surveyed during 1996, this study therefore examined both positive and negative attitudes to dentistry. It was initially predicted that dentally anxious individuals would be more likely to have negative feelings about dentistry than non-dentally anxious individuals, and would attribute this attitude to specific experiences. The study found that the majority of participating students had a positive attitude toward dentistry, and that participants with low levels of dental anxiety were more likely to have a positive attitude than those with a high level of anxiety. However, highly dentally anxious individuals were just as likely to feel positive toward dentistry as they were to feel negative. A substantial proportion of students claimed to have had painful or distressing experiences at the dentist during their adolescence. However, experiencing a painful or distressing incident was not related to having a negative attitude. The majority of the students who felt negative toward dentistry attributed this attitude to an unspecific experience, although dentally anxious individuals were likely to be more specific than non-dentally anxious individuals. Women participants appeared to have experienced painful or distressing incidents at a younger age than the men. The authors concluded that the factors involved in the development and maintenance of an individual's attitude toward dentistry are complex, and that dentists should be concerned with the promotion of positive attitudes rather than attempting to resolve negative ones.

Gender and age differences in attitudes to dental pain and dental control

In the literature, it is usual to find women and younger subjects reporting higher levels of dental anxiety than men and older subjects. Fear of pain was found to be the most important predictor of dental anxiety and issues of control were also related to such anxiety. Therefore, it was predicted that gender and age differences would be reflected in attitudes to pain and control. Subjects were randomly selected from the voters' list in metropolitan Toronto and mailed a questionnaire with a request for cooperation in a study of their thoughts, feelings, and behaviour regarding dental treatment. The questionnaire included demographic data, measures of dental anxiety and painful experiences as well as the Pain Anxiety Symptoms Scale and the Iowa Dental Control Index. The results supported the main predictions. In addition, attitudes to pain and control were found to be complex phenomena with characteristic gender differences.

Overlap between dental anxiety and blood-injury fears: psychological characteristics and response to dental treatment

The relationship between dental anxiety and blood/body injury (BI) fears was examined in a sample of 1420 adults. Based on their responses to two mail questionnaires, they were classified into one of four groups: Group 1--neither dentally anxious nor BI fearful; Group 2--BI fearful only; Group 3--dentally anxious only; Group 4--both dentally anxious and BI fearful. Overall, only 16% of dentally anxious subjects were BI fearful while 31.6% of those with high levels of BI fears were dentally anxious. While subjects in Group 2 were more fearful of dentistry than those in Group 1, they were substantially less so than subjects in Groups 3 and 4. Moreover, even BI stimuli in the dental setting evoked lower levels of anxiety for subjects in Group 2 compared to Group 3 and 4. However, rates of fainting or near fainting experiences in the dental situation were similar for all three groups. Group 3 and 4 were similar in terms of fear evoking stimuli and patterns of anxiety response. Subjects in Group 4 had more agoraphobic symptoms and social interaction fears and had higher scores on the Anxiety Sensitivity Index and Speilberger Trait Anxiety Index. This suggests that Group 4 is comprised of individuals who are more likely to be multiphobic and exhibit generalized anxiety states. Although BI fears are a significant component of dental anxiety, their overall contribution is relatively small.

Who is dentally anxious? Concordance between measures of dental anxiety

Studies of the prevalence of dental anxiety in general population samples have produced estimates which range from a low of 2.6% to a high of 20.4%. It is not clear whether these reflect real differences among populations or whether they are the result of the use of different measures and different cut-off points. We undertook a large scale mail survey of dental anxiety in a random sample of the adult population living in Metropolitan Toronto designed to assess the performance of and agreement between three measures. These were Corah's DAS, the single item used by Milgrom and colleagues in Seattle and the ten-point fear scale used by Gatchel. These measures and their published cut-off points produced prevalence estimates of 10.9%, 23.4% and 8.2% respectively. While there was a significant association between scores on pairs of measures the agreement between them was far from perfect. Kappa values ranged from 0.37 to 0.56, indicating only fair to moderate agreement beyond chance. There was evidence to indicate that the dentally anxious subjects identified by each measure differed according to certain behavioural and other characteristics. The results of the study suggest the need to revisit the issue of measurement in studies of dental anxiety.

Negative dental experiences and their relationship to dental anxiety

Although negative dental experiences are often cited as the major factor in the development of dental anxiety, very few studies have provided data on their prevalence. The studies that are available used limited samples from which it is not possible to generalise, or confined their enquiries to painful experiences only. In this paper data are provided on negative dental experiences and their relationship to dental anxiety obtained from a large, random sample of the general population. Just over three-quarters reported what are termed as direct negative experiences; 71 per cent had had experiences that were painful, 23 per cent experiences that were frightening and 9 per cent experiences that were embarrassing. Such experiences were not confined to childhood. For 23 per cent, the first experience of this kind happened during adolescence and for 40 per cent in adulthood. The relationship between these experiences and dental anxiety was strong. Subjects reporting all three types of experience were 22.4 times at risk of being dentally anxious than subjects reporting none of them. The data suggested that the nature of these unpleasant experiences was more important than the age at which they occurred in predicting dental anxiety. One third of dentally anxious subjects reported a negative response experience in the form of feeling faint, fainting or having a panic attack while at the dentist. Further research using more appropriate methods is needed to clarify the role of dental experiences in the genesis of dental anxiety.

Disproportionate dental anxiety in the over 50s

Explanations of dental anxiety in terms of either conditioning or personality predispositions alone are not sufficient to account for all individuals presenting with dental anxiety, since they are not a homogenous group. It was hypothesized that individuals, with wide ranging anxiety problems would be more likely to carry dental anxiety into old age. This prediction was supported by a comparison of older dentally anxious individuals with other older individuals who admitted to dental anxiety previously but were no longer dentally anxious. The results were interpreted in terms of Lang's bioinformation model of anxiety.

The 42.5 kDa subunit of the NADH: ubiquinone oxidoreductase (complex I) in higher plants is encoded by the mitochondrial nad7 gene

The N-terminal amino acid sequence of a 42.5 kDa subunit of the NADH: ubiquinone oxidoreductase (complex I) from potato has been determined by direct protein sequencing. The sequence was found to be homologous to that of the nuclear-encoded 49 kDa complex I subunit of bovine and Neurospora mitochondria and to the sequence deduced from the mitochondrial nad7 gene identified in the mitochondrial (mt) DNA of tryp anosomes and the moss Marchantia. An oligonucleotide probe derived from the potato N-terminal protein sequence hybridized only to the plant mtDNA. Immunoprecipitation of in-organello 35S-labelled potato and wheat mitochondrial translation products with an antibody directed against the Neurospora 49 kDa complex I subunit indicates that at least in these plants the NAD7 protein is synthesized within the organelle. Comparisons of genomic, cDNA and protein sequences of the 5' coding region reveal three codons that are changed by RNA-editing and confirm translation of the edited transcripts in plant mitochondria. The NAD7 protein appears to undergo post-translational processing since the N-terminal methionine residue is absent from the mature mitochondrial protein.

Long-term follow-up of treated dental phobics

Behavioural treatment programmes have been shown repeatedly to be effective in alleviating dental anxiety but few studies have provided long-term follow-ups. In this study, dentally anxious Ss who had completed a 4-session behavioural group programme were followed up for periods between 1 and 4 years after successful completion of treatment. It was hypothesized that dental visit satisfaction would be associated with regular dental attendance. 88% of Ss contacted agreed to cooperate; of these, 70% were still maintaining regular check-ups. There were no differences between regular and irregular attenders in terms of age, gender, education, marital status, degree of pre-treatment avoidance or time elapsed since completion of the programme. However, Ss who did not see their dentists regularly were more likely to have shown higher levels of anxiety immediately after completing the programme, less concordance between the subjective and overt behavioural aspects of anxiety and to have experienced more invasive than non-invasive procedures than the others. It was argued that dentally anxious individuals are not a homogeneous group and that a better understanding of their individual differences would lead to the development of more efficacious treatment procedures.

Purification of the NADH:ubiquinone oxidoreductase (complex I) of the respiratory chain from the inner mitochondrial membrane of Solanum tuberosum

The plant NADH:ubiquinone oxidoreductase (or complex I) was isolated from potato (Solanum tuberosum) mitochondria. The multisubunit enzyme was solubilized with detergents, Triton X-100 and 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), out of the inner mitochondrial membranes and purified by hydroxylapatite and gel filtration chromatography. The preparation was found to be virtually free of any ATPase or transhydrogenase contamination. Complex I of potato is composed of at least 32 individual subunits as detected in silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis and has a total molecular mass of about 900 kDa. The enzyme preparation showed an NADH:ubiquinone-2 reductase activity of 11.5 mumol x min-1 x mg-1 and is strongly inhibited by rotenone. Heterologous polyclonal antibodies against the 70- and 49-kDa subunits of the Neurospora crassa complex I and against the wheat NAD9 subunit cross-reacted specifically with the respective potato subunits. Four of the 10 NH2-terminal sequences determined show significant similarities to Neurospora or bovine complex I subunits and allow a tentative assignment of these subunits.

Clinical correlates of dental anxiety among older adults

Most studies of the relationship between dental anxiety and oral health status have used subjective rather than clinical indicators of oral health. In this paper we examine differences between older adults who are and are not dentally anxious using a broad range of clinical measures. The data show that dentally anxious individuals were more likely to be edentulous, and among the dentate, had more missing and fewer filled teeth. As a result, dentally anxious dentate subjects were more likely to need prosthodontic treatment. They were also more likely to need immediate treatment for the relief of pain and infection and periodontal care. There was evidence to suggest differences in patterns of dental treatment between those who were and were not dentally anxious and some evidence consistent with the hypothesis that aging influences the relationship between dental anxiety and oral health status.

Dental visit satisfaction in a group of adults aged 50 years and over

Studies have found that utilization of dental services is generally less common than utilization of medical services, particularly by older persons. Because satisfied dental patients were found to be greater users of the service than nonsatisfied patients, it was decided to investigate the correlates of dental visit satisfaction in older subjects. Predictions that satisfaction would be positively related to regular use of dental services and negatively related to dental anxiety were confirmed. The results also suggested that older dental patients have different expectations of their dentists than younger ones.

Comparison between FSS-II scores of two groups of university students sampled 15 yr apart

Undergraduate students were contacted in classes at Memorial University of Newfoundland during 1975 and asked to complete the FSS-II, on a voluntary basis; 511 students (232 male and 279 female subjects) provided enough data for analyses. In 1990, the same procedure was carried out, resulting in a comparable group of 359 students (161 male and 198 female subjects). Contrary to predictions, the 1990 students were more fearful than the 1975 group and the increase in fearfulness was contributed exclusively by women students. The component of fear contributing most to this increase related to social evaluation and violence.

Dental fear and anxiety in an older adult population

A random sample of 580 people aged between 50 and 89 yr completed a questionnaire containing two measures of dental fear and anxiety. One of these was Corah's Dental Anxiety Scale (DAS) and the other a scale derived from the Structured Interview for Assessing Dental Fear (SIADF). The mean score on the DAS was 7.8, and 8.4% of subjects were classified as dentally anxious. There were no differences in mean DAS scores by sex but significant differences by age, with younger individuals having higher scores (P less than 0.0001). The edentulous had significantly higher scores than the dentate (P less than 0.001). Scores on the SIADF scale were higher among younger individuals (P less than 0.0001), the edentulous (P less than 0.01) and women (P less than 0.05). Older adults who were dentally anxious were less likely to report a regular source of dental care and a dental visit in the previous year and more likely to report having avoided or delayed dental treatment. Possible explanations of higher dental anxiety scores among younger persons and the edentulous are reviewed.

Self-reported fears (FSS-II) of subjects aged 50 years and over

From studies of fears in children and adolescents, it was concluded that fears decrease with age and that girls show more fears than boys at the approach of adolescence. Community studies of adult fears as well as psychopathology have suggested a decrease in fears and phobic and anxiety symptoms with age. However, little is known of the distribution of fears in older adults. In view of this, the FSS-II was administered to a group of individuals aged 50 yr and over, as part of a larger epidemiological investigation of the oral health and treatment needs of older adults within Metropolitan Toronto. The results supported the hypothesis that the gender differences which ermerge at adolescence hold up into old age. The predicted age decrease in fearfulness was also supported.

The effect of concordance in the treatment of clients with dental anxiety

This study followed from an earlier case study in which an agoraphobic client was treated daily for a period of four weeks by in vivo exposure. Ratings of his perceived anxiety responses in the behavioural, cognitive, and physiological systems were monitored throughout treatment. Concordance between these ratings was associated with positive outcome. This study was an attempt to replicate some of these findings. A group programme involving four sessions in which clients were taught anxiety management skills, exposed in imagination to situations relating, to dentistry, and given homework assignments was carried out with clients presenting with disproportionate dental anxiety. The subjects were obtained by means of local newspaper and radio advertisements and randomly assigned to a massed or spaced treatment condition. It was predicted that the massed condition involving shorter intersession intervals would be superior at producing habituation and concordance than the spaced condition. The results failed to show differences between the massed and spaced treatment condition with regard to concordance and outcome. However, it was confirmed, once more, that concordance between the three modes of anxiety responding was positively related to outcome.

What dental phobics say about their dental experiences

Previous surveys have indicated that there is a substantial proportion of dentally anxious individuals in the general population. Many of these individuals avoid contact with dentistry as much as possible, while fearful individuals who present themselves for treatment are probably too uncomfortable or too afraid to make their views known. Consequently, a study of the feelings and attitudes of a group of dental phobics was carried out as part of a larger study of the efficacy of psychological treatments for excessive dental anxiety. The subjects were recruited by means of a newspaper advertisement and asked to complete a questionnaire designed to obtain information regarding their dental experiences and attitudes. Twenty-three individuals provided enough data for analysis. They were distributed widely in terms of age, education, income levels, and general fearfulness. They reported less satisfaction with the level of understanding or acceptance found in the last dentist they had seen than with the dentist's level of technical competence and the diagnostic information they received. Dental phobics who had been to a dentist in the past year were generally more satisfied with their dentist than those who had not. It is suggested that a good dentist-patient relationship based on understanding and acceptance is an important factor in overcoming the avoidance of fearful patients.

Personality characteristics versus medical and dental experiences of dentally anxious children

There is some conflicting evidence in the literature regarding whether dental phobia is a circumscribed fear or an instance of general fearfulness. In an attempt to tease out the effect of general fearfulness from that of aversive dental experiences, mothers of a group of 12 year-old children of both sexes were interviewed regarding their child's temperament and early dental and medical experiences. The results indicated that previous aversive dental experiences were more closely related to dental anxiety than was general fearfulness. Dentally anxious boys appeared to have been influenced by external factors, while the dentally anxious girls' influences appeared to be internal ones. Finally, early behavioral signs of distress in the operatory were predictive of later dental anxiety.

A longitudinal study of the contribution of dental experience to dental anxiety in children between 9 and 12 years of age

Dental records of a group of children of both sexes were examined systematically over a period of 3 years to determine if the quantity and quality of their dental experience would be associated with increases in dental anxiety. The study was a follow-up of an earlier cross-sectional survey in which older children had demonstrated increases in dental anxiety with age. According to the evidence obtained from their dental records, the children were divided into four groups depending on their patterns of attendance (regular/irregular) and whether or not they had received invasive treatment. The results indicated that children who did not receive invasive treatment during the period under scrutiny were significantly more anxious than those who had. On the other hand, the dental anxiety of children who attended regularly and received invasive treatment did not change significantly. This applied to boys and girls alike.

Agoraphobics' understanding of the development and maintenance of their symptoms

A 24-item test was devised to study the degree of understanding a group of agoraphobics had of the etiology and behavioral treatment of their symptoms before and after treatment, whether understanding was related to mode of symptom acquisition and, finally, if increase in understanding was related to treatment outcome. Clients were found to be ill-informed in areas most directly related to realistic exposure strategies, but there was no difference between those who had conditioning as opposed to cognitive acquisition histories. Changes in understanding were found to be related to outcome measures.

Some characteristics of regular and irregular attenders for dental check-ups

Previous surveys of dental care have shown that a substantial proportion of people do not attend dentists regularly. Reasons given for such non-attendance included fear as well as other negative attitudes. Recent studies have attributed fear of dentistry to painful traumatic experiences. The purpose of this study was to compare regular and irregular or non-attenders for dental check-ups on a number of variables, including sex and age, self and family dental anxiety, and previous dental experience. A sample of 531 subjects of both sexes and ranging in age from 16 to 78 years was made available by two large organizations in London and surveyed during office hours. Dental anxiety appeared as a significant factor in non-attendance but there was little support for a simple conditioning hypothesis to explain dental anxiety. Attenders and non-attenders differed markedly in their perception of dentists but there was no difference between the groups as to sex and age.

Patients' perception of dentists' positive and negative attributes

Earlier studies have shown that dental patients concern themselves with the personality characteristics of their dentists as well as with their professional competence. The present study is part of a wider survey which compared the characteristics of regular and irregular or non-attenders for dental check-ups. In this article patients' characteristics such as sex, age, level of dental anxiety and certain previous dental experiences were related to their perceptions of dentists' positive and negative attributes. The results confirmed previous findings that dentists were seen generally by their patients in a favourable light. Respondents who admitted to higher levels of dental anxiety were more likely to choose more negative attributes and less positive ones than respondents who admitted to lower levels; women, younger subjects and the dentally anxious consistently chose unsympathetic and indifferent as the two top negative characteristics of their dentists.