Search PubMed⌕ Search

Biomedical subjects

W M Thomson

Publications and source records attributed to W M Thomson.

At least 37 records · Page 2Linked to original sources
PubMed2002

Medications taken by 26-year-olds.

BACKGROUND: Most descriptive pharmacoepidemiological reports are from studies of older people, and little is known about medication use by younger adults. AIMS: The aim of the present study was to examine the prevalence of medication usage in the previous 2 weeks among young adults. METHODS: Detailed information was collected on medications taken by 26-year-old participants in the longstanding Dunedin Multidisciplinary Health and Development Study. RESULTS: At age 26, 980 (96.2%) of the surviving cohort participated; medication data were available for 978 individuals, of whom 78.1% had taken one or more prescribed or over-the-counter medications. Medication use was higher among females. The most prevalent drug categories were analgesics (taken by 22.8% of the sample), hormonal contraceptives (21.9%; 44.7% of females), nutrient supplements (17.6%) and anti-asthma drugs (11.1%). CONCLUSIONS: The prevalence and pattern of medication use among younger adults differ from those reported for older age groups. Asthma appears to be the most prevalent chronic medical condition requiring pharmacological intervention (and for which medical care has been sought) among younger adults. The low rates of use of antidepressants and anxiolytics suggest that common psychiatric disorders may currently go unrecognized or untreated among young adults, and the high prevalence of 'third generation' oral contraceptive use among females is of particular concern.

Adult↗
PubMed2002

Were NZ's structural changes to the welfare state in the early 1990s associated with a measurable increase in oral health inequalities among children?

OBJECTIVE: To test the hypothesis that the 1990-91 social and economic policy changes in New Zealand were associated with a subsequent increase in socioeconomic and ethnic inequalities in the dental caries experience of five-year-old children. METHOD: Dental caries data from the School Dental Service treating the greater Wellington area were analysed for the period 1995-2000. Multivariate models were developed for deciduous caries prevalence (logistic regression) and severity (negative binomial regression). RESULTS: In the years 1995, 1996, 1997, 1998, 1999 and 2000, complete data were available for 2,627, 3,335, 4,404, 4,155, 3,154 and 2,804 children, respectively. Ethnic and socio-economic differences in caries prevalence and severity were substantial and persistent during the observation period. Where caries severity was concerned, there was a significant interaction between time and Maori ethnicity, indicating that (on average) the oral health of Maori children deteriorated in comparison to their European counterparts. CONCLUSIONS: The early-1990s social and economic policy changes were associated with an apparent widening of ethnic inequalities in caries severity among five-year-old children. IMPLICATIONS: Economic rationalism appears to have oral health disadvantages for non-European children. Before implementation of proposed major social and economic policy changes, policymakers should consider their health implications.

Child↗
PubMed2002

Risk indicators for tooth wear in New Zealand school children.

AIM: To investigate the prevalence and severity of tooth wear in the primary dentition of a representative sample of New Zealand school children and relate these to possible risk factors. DESIGN: A cross-sectional study. SETTING: Primary schools in Dunedin, New Zealand. PARTICIPANTS: 104 children of both sexes, aged between 5 and 8 years, randomly selected. METHODS: Clinical examinations of the buccal, occlusal/incisal and lingual surfaces of deciduous canines and molars. MAIN OUTCOME MEASURE: Degree of wear and the presence of dentinal cupping of teeth. Information on weaning and consumption of fruit-based drinks at bed time, frequency of consumption of fruits, yoghurt, pickled foods, fizzy and fruit-based drinks. RESULTS: The prevalence of tooth wear was similar in boys and girls and there were no significant differences between sides of the arches. A high percentage (82%) of children had at least one primary tooth with dentine exposed. While maxillary canines showed the greatest prevalence of dentine exposed, maxillary molars displayed the greatest prevalence of cupping. Severe tooth wear was less prevalent among children weaned after 12 months (14.3%) than those weaned earlier (27.9% P < 0.01). There were no statistically significant associations between wear and the consumption of fruit, yoghurt, pickled foods, fizzy drinks or fruit-based drinks. CONCLUSIONS: Tooth wear associated with dentine exposure is common in 5-8 year old children. This is not significantly associated with dietary factors, but appears to be related to early weaning from the breast.

Beverages↗
PubMed2002

Partial- or full-mouth approaches to assessing the prevalence of and risk factors for periodontal disease in young adults.

BACKGROUND: While partial-mouth recording is often used in epidemiological studies of periodontal disease because of the efficiencies afforded in data collection, there has been no investigation of the extent to which information is lost in studies of young adults using the combined attachment loss (CAL) approach. METHODS: A random sample of 25- and 26-year-olds was periodontally examined at 3 sites per tooth in all 4 quadrants. The analysis obtained full-mouth prevalence estimates for gingival recession (GR), probing depth (PD), and CAL. The half-mouth analyses took 3 forms: 1) estimates from each of the left and right sides were obtained and compared; 2) estimates were obtained separately and compared for quadrants 1 and 3 (upper right and lower left), and quadrants 2 and 4 (upper left and lower right); and 3) estimates were obtained from a diagonal half-mouth count, whereby quadrants 1 and 3 were analyzed for study participants whose identification number was odd, and quadrants 2 and 4 were analyzed for the remainder. The utility of the half-mouth and full-mouth approaches in analytical epidemiology was examined by estimating the strength of the association between periodontitis prevalence and smoking, male gender, and episodic use of dental care. RESULTS: Of the 169 participants examined, 100 (59.2%) were female, 54 (32.0%) were smokers, and 78 (46.2%) were episodic dental visitors. The difference in prevalence estimates obtained from the different methods was considerably greater for GR than for PD and CAL. The unadjusted odds ratio (OR) for the prevalence of 1 or more teeth with > or = mm of CAL among smokers was 2.3 (95% confidence interval [CI] 1.0, 5.3) using the full data set and 2.4 (95% CI 0.9, 6.1) using the diagonal half-mouth approach. Similarly close odds ratios were observed for males and, to a lesser extent, for episodic dental visitors. CONCLUSIONS: Wherever possible, full-mouth data should be collected for descriptive epidemiological studies of periodontal disease, but where resource and time constraints mean that half-mouth examinations must be used, analytical studies of periodontitis should not be unduly affected by the loss of information. However, where the primary focus of the latter is upon gingival recession, the full-mouth design should be used in order to capture all relevant information, and attention should be directed to making economies in other areas of the data collection process.

Adult↗
PubMed2001

Determinants of early- vs late-onset dental fear in a longitudinal-epidemiological study.

A longitudinal investigation of risk factors for early- and late-onset dental fear was conducted. Early-onset dental fear was related to conditioning experiences (indexed via caries level and tooth loss), service use patterns, stress reactive personality and specific beliefs about health professionals. Late-onset dental fear was related to aversive conditioning experiences, irregular service use and an external locus of control. In contrast to recent findings for dental anxiety, personality factors were not strongly related to the onset of dental fear in young adulthood. The key role played by conditioning events in the development of both early- and late-onset dental fear was confirmed. Conditioning events appear to play a different role in the development of dental fear vs dental anxiety. This may reflect important, but largely ignored differences between these two closely-related constructs. Interventions for early-onset dental fear should aim to modify both the dental fear and the personality vulnerabilities that may contribute to the development of dental fear early in the life-course.

Adolescent↗
PubMed2001

Smoking in adolescence as a predictor of early loss of periodontal attachment.

OBJECTIVES: On the basis of information from studies of older adults, smoking is considered to be an important risk factor for periodontal disease. Examining periodontal loss of attachment among younger adults means a lower contribution from cumulative exposure to other environmental risk factors. The aim of this study was to examine the role of chronic exposure to cigarette smoking as a risk factor for greater prevalence and extent of periodontal loss of attachment among 26-year-old participants in a longstanding prospective cohort study. METHODS: Loss of attachment (LOA) was measured at three sites per tooth in two randomly selected contralateral quadrants (one upper, one lower). Cigarette smoking history was obtained at ages 15, 18, 21 and 26, and used to categorise participants as "never-smokers", "ever-smokers", "long-term smokers" or "very longterm smokers". RESULTS: Periodontal data were available for 914 Study members, among whom the prevalence of LOA of 4+mm was 19.4%. Among those who smoked at ages 15, 18, 21 and 26, it was 33.6%, and, after controlling for sex, selfcare and dental visiting, they were nearly three times as likely to have one or more sites with 4+mm LOA. CONCLUSIONS: Chronic exposure to smoking is a strong predictor of periodontal disease prevalence in young adults.

Adolescent↗
PubMed2001

Psychological disorders and dental anxiety in a young adult population.

OBJECTIVES: It has been suggested that some individuals who are fearful or anxious about dental treatment have a constitutional vulnerability to anxiety disorders as evidenced by the presence of multiple fears, generalized anxiety or panic disorders. This paper compares the prevalence of psychological disorders among dentally anxious and non-anxious groups drawn from the general population. METHODS: Data were obtained as part of a birth cohort study when study members were aged 18 years. They were assessed using the Dental Anxiety Scale (DAS) and the Diagnostic Interview Schedule (DIS). The disorders diagnosed by the DIS were major depressive episode, dysthymia, generalized anxiety disorder, panic disorder, agoraphobia, social phobia, simple phobia, obsessive compulsive disorder, conduct disorder, cannabis and alcohol dependence. RESULTS: Overall, 12.5% of study members had DAS scores of 13 or more and were considered to be dentally anxious. Those who were dentally anxious were more likely than the non-anxious to be diagnosed with one or more psychological disorders (55.0% vs. 42.3%). However, those with DAS scores of 13 or 14 (moderately dentally anxious) were broadly similar to the non-anxious in terms of their psychological profile. This excess prevalence of psychological disorder was largely accounted for by high rates of disorder among those with DAS scores of 15 or more (highly dentally anxious). The highly anxious were more likely than the non-anxious to have a diagnosis of conduct disorder, agoraphobia, social phobia, simple phobia or alcohol dependence. Odds ratios ranged from 2.8 to 5.0 after controlling for the effects of gender. The data also suggested that dentally anxious individuals with psychological disorders were more likely to maintain their anxiety over time. CONCLUSIONS: In this population of young adults, high rates of psychological disorder were characteristic of those with high levels of dental anxiety. Psychological disorder was related to the maintenance of dental anxiety over time.

Adolescent↗
PubMed2001

Third molar outcomes from age 18 to 26: findings from a population-based New Zealand longitudinal study.

OBJECTIVE: The purpose of this study was to describe the presence and impaction status of people's third molars at age 18 years, as well as the observed changes in their clinical status between ages 18 and 26 years. STUDY DESIGN: Eight hundred twenty-one participants in a prospective cohort study were dentally examined at ages 18 and 26 years, and panoramic radiographs were taken at age 18 years but not at 26 years. For each tooth, its radiographic impaction status at age 18 years was compared with the clinical status by age 26 years. RESULTS: Of the 2857 third molars assessed at age 18 years, 92.8% were able to be followed up clinically at age 26 years. Approximately 54.9% of the teeth that were not impacted by age 18 had erupted by 26 years. Of the teeth that were impacted by age 18, 33.7% had fully erupted by age 26, 31.4% had been extracted, and 13.1% remained unerupted. Of the maxillary teeth that were categorized as "impacted" at age 18 years, 36.2% had fully erupted by age 26, whereas only 25.6% of the mandibular teeth had done so (P <.01). Fewer mandibular teeth than maxillary teeth remained unerupted by the time the patient was 26 years old (27.4% and 41.4%, respectively; P <.01), but there was no significant difference between the jaws in the proportion of impacted teeth at age 18 years that had been extracted by age 26 years (29.6% and 30.3%, respectively). For mesioangularly impacted third molars, 39.3% of maxillary teeth and 20.4% of mandibular teeth had fully erupted by age 26. Of the third molars that were mesioangularly impacted at age 18 years, 39.3% of maxillary teeth and 20.4% of mandibular teeth had fully erupted by age 26 years, whereas almost one-third of each had been extracted. Of the distoangularly impacted third molars, 20.4% of the maxillary teeth and one-third of the mandibular teeth had erupted by age 26, with 21.6% of the maxillary teeth and 31.6% of the mandibular teeth having been extracted. CONCLUSION: Other than horizontally impacted third molars, a substantial proportion of other impaction types do erupt fully, and radiographically apparent impaction in late adolescence should not be sufficient grounds for their prophylactic removal in the absence of other clinical indications.

Adolescent↗
PubMed2001

One-year prospective evaluation of the early loading of unsplinted conical Brånemark fixtures with mandibular overdentures immediately following surgery.

BACKGROUND: Prospective evaluation of the early loading of unsplinted Brånemark implants with mandibular overdentures opposing conventional dentures is not evident in the implant-related literature. PURPOSE: To clinically evaluate progressive and early loading of 20 unsplinted conical Brånemark implants in edentulous mandibles with overdentures. MATERIALS AND METHODS: Ten edentulous patients all had two conical Brånemark implants placed in the anterior mandible with mandatory primary stability with bicortical anchorage. Ball abutment connection was performed simultaneously. Previously constructed conventional mandibular dentures were temporarily relined with tissue conditioner postoperatively and worn with moderation for the first 2 weeks to allow progressive loading. Early loading of the implants followed after 2 weeks, with inclusion of the respective matrices in the mandibular dentures, using a definitive reline procedure. RESULTS: All patients successfully functioned with their mandibular implant overdentures from 2 to 52 weeks postoperatively. Mean marginal bone loss was within established criteria for success: 0.22 mm (SD = 0.48 mm) mesially and 0.30 mm (SD = 0.39 mm) distally on the conical implants. Mobility tests using the Periotest instrument became more negative, although not at statistically significant levels. Difficulties in the management of the peri-implant mucosa between surgery and loading at 2 weeks were observed in 40% of the patients. CONCLUSIONS: These preliminary 1-year results show that successful early loading of unsplinted conical Brånemark implants with mandibular overdentures is possible.

Aged↗
PubMed2001

One-stage operative procedure using two different implant systems: a prospective study on implant overdentures in the edentulous mandible.

BACKGROUND: Evidence-based reports are needed to support the application of a one-stage surgical protocol for unsplinted implants supporting mandibular overdentures. PURPOSE: To examine the feasibility and success of using two different dental implant systems (originally designed for two-stage operative technique) using a one-stage operative procedure in patients being rehabilitated with implant mandibular overdentures. MATERIALS AND METHODS: The study sample involved 24 edentulous subjects (aged 55-80 yr) randomly allocated to two different implant systems, one with a machined titanium implant surface (Steri-Oss, Nobel Biocare, Göteborg, Sweden) and the other with a roughened titanium surface (Southern Implants, Ltd., Irene, South Africa). Two unsplinted implants to support implant overdentures were placed in the anterior mandible of all patients, using a standardized one-stage surgical and prosthodontic procedure. Primary stability and bicortical anchorage of the implants was mandatory before healing abutments were connected at the time of implant placement. Implant overdentures and their respective matrices were inserted following a standard 12-week healing period. Data relating to mobility tests, radiographs, and peri-implant parameters were documented at 12, 16, and 52 weeks after surgery. RESULTS: A success rate of 95.8% for the Steri-Oss and 100% for the Southern Implants was found, without any statistically significant differences in the marginal bone loss. Significant changes in Periotest values were observed for both types between 12 and 52 weeks (p < .001). Minor changes were observed in the peri-implant parameters evaluated. CONCLUSIONS: These preliminary findings show a successful application of this one-stage approach for unsplinted implants supporting mandibular overdentures with Steri-Oss and Southern Implant Systems.

Aged↗
PubMed2001

Psychological disorder, conditioning experiences, and the onset of dental anxiety in early adulthood.

Most studies examining the origins of dental fear and anxiety have relied on cross-sectional data. These are subject to several problems, such as recall and uncertainty concerning temporal relationships. This paper uses longitudinal data from the Dunedin Multidisciplinary Health and Development Study to assess risk factors for the development of dental anxiety in persons between the ages of 18 and 26 years. It was hypothesized that psychological factors would be as important as conditioning experiences in the genesis of dental anxiety over this period. The eight-year incidence of dental anxiety was 16.5%. Five variables entered models predicting onset: multiple fears, symptoms of substance dependence, previous experience of invasive dental treatment, dental visiting pattern, and the extraction of one or more teeth. Separate analyses for those avoiding and those using dental services resulted in different explanatory models. These results indicated that both psychological and conditioning variables contributed to the development of dental anxiety in this population of young adults.

Adolescent↗
PubMed2001

IL-1 genotype and adult periodontitis among young New Zealanders.

Several recent studies have investigated the association between interleukin-1 genotype and periodontitis in clinical samples, where generalizability is an issue. The aim of this study was to investigate the association between adult periodontitis and IL-1 genotype in a population-based sample of 26-year-olds. Based on probing depth (PD) measurements, participants were divided into three disease groups: "Severe" (1+ teeth with 5+mm PD; N = 25), "Moderate" (2+ teeth with 4+mm PD; N = 36), and "Controls" (the remainder; N = 800). The "periodontitis-associated genotype" (PAG; Kornman et al., 1997) was present in 20.0% of the "Severe" group and in 34.8% of "Controls", whereas the IL-1A(+4845) [1,1]/IL-1B(+3953) [2,2] genotype was present in 12.0% and 0.9%, respectively. After controlling for sex, smoking status, and plaque levels, we found that those with IL-1B(+3953) [1,1]/IL-1A(+4845) [2,2] had 12.3 times the odds of being in the "Severe" group. Analysis of these data suggests that the IL-1A(+4845) [1,1]/IL-1B(+3953) [2,2] genotype is associated with periodontal disease in this young population. Future periodontal data collections as this cohort ages are required to confirm the predictive value of that genotype.

Adult↗
PubMed2001

Onset of and patterns of change in dental anxiety in adolescence and early adulthood: a birth cohort study.

OBJECTIVE: To assess the onset of and patterns of change in dental anxiety during adolescence and early adulthood. DESIGN: A birth cohort study of 1,037 individuals born in Queen Mary Hospital, Dunedin, New Zealand between 1 April 1972 and 31 March 1973. Data were collected from these individuals at birth, every two years between the ages of 3 and 15 and at 18, 21 and 26 years. STUDY MEMBERS: Data on dental anxiety were obtained at the 15, 18 and 26-year assessments from 678 study members. OUTCOMES: Dental anxiety was assessed using the Dental Anxiety Scale. Study members with a score of 13 or over were classified as being dentally anxious. RESULTS: The prevalence of dental anxiety increased from 10.6% at age 15 years to 13.3% at 18 years and 21.1% at 26 years. Of the 31.2% who were anxious at one or more data collection periods, approximately one third were anxious by the age of 15, one third became anxious between 16 and 18 years and one third between 18 and 26 years. High rates of remission were observed. Of 72 study members who were dentally anxious at 15 years, 22% were persistent cases, anxious at all three data collection points; 24% were recurrent cases, anxious at 26 but not anxious at 18 years; and 54% were remitted cases, no longer anxious at 26 years. There were no gender differences in the onset and course of dental anxiety over the developmental periods observed. CONCLUSIONS: The period of observation was one of instability with respect to anxiety about dental treatment. Early adulthood in particular appeared to be a life stage during which this population was vulnerable to the onset of dental anxiety. This may be related to dental disease and treatment factors, or changing psychological states during significant life transitions.

Adolescent↗
PubMed2001

Use of dental services by 26-year-old New Zealanders.

The use of dental services and its oral-health associations were investigated in a birth cohort of 26-year-olds in order to examine the oral health and health-care effects of the change in entitlement to State assistance for dental care which occurs when the eighteenth birthday is reached. Fewer than half were routine users, and this proportion was greater among females. More of those who were episodic users at age 26 rated their oral health poorly, and more than one in six had had a tooth extracted since age 18 because of caries. Those who used dental services only when they had a problem not only had greater caries experience by the age of 26, but also their caries increment over the previous 8 years was also greater. Visiting the dentist for routine check-ups was associated with better long-term oral-health consequences than only going when there was a problem.

Adolescent↗
PubMed2001

The readiness of New Zealand general dental practitioners for medical emergencies.

A risk of medical emergency accompanies every dental procedure, but little is known of general dental practitioners' readiness for such events. The few previous studies have shown that nearly all dentists have received training in medical emergencies at some time, most of this training being postgraduate. Up to 20 percent of dentists have reported feeling inadequately prepared for medical emergencies, and most are receptive to the idea of receiving further medical emergency-related training. We conducted a postal survey of 314 dentists concerning their readiness for, and experience of, medical emergencies within general dental practice; 199 dentists (63.4 percent) responded. Medical emergencies had occurred in 129 practices (65.2 percent) within the previous 10 years, at a mean rate of 2.0 events per 10,000 patients treated under local analgesia, other forms of pain control, or sedation. Vaso-vagal events had occurred in 121 (61.1 percent) practices within the previous year, the mean rate being 6.9 events per 10,000 patients treated using the same modes. More than half the respondents were dissatisfied with the training they had received for medical emergencies as undergraduate students, and 28 (14.1 percent) currently felt inadequately prepared for an emergency in practice. When asked how their preparedness could be improved, 165 (83.3 percent) opted for hands-on courses, 15 (7.5 percent) opted for lectures alone, and 5 (2.5 percent) opted for other courses alone. One in 20 felt no need for further training. Further training in the management of medical emergencies should be made available to New Zealand's dentists.

Cardiopulmonary Resuscitation↗
PubMed2000

Nutritional supplement use among 26-year-olds.

AIMS: To estimate the prevalence of use of nutritional supplements among young adults, to examine the source of those supplements and to investigate sex differences in usage. METHODS: Participants in the age-26 years assessments of the Dunedin Multidisciplinary Health and Development Study were asked to bring containers for any medication (including supplements) taken in the previous two weeks. Medication data (including prescription source) were recorded and analysed for 978 of 980 Study members. RESULTS: The prevalence of supplement use was 16.6%; 20.4% among females and 13.3% for males (p<0.01). Multivitamin preparations were the most widely consumed, followed by water-soluble vitamin supplements (such as folate and vitamin C). Folate use was higher among females and was taken by 35.7% of pregnant females. Most supplements were self-prescribed, although a doctor had prescribed over one-third of the mineral supplements. Most supplements had been taken for weeks or months, rather than years. CONCLUSIONS: Nutritional supplement usage among young adults is reasonably common, and involves a wide range of preparations. The extent of use among younger people suggests a need for regulation of their manufacture, sale and usage, and research to examine their efficacy.

Adult↗
PubMed2000

Further testing of the xerostomia inventory.

OBJECTIVE: To examine the concurrent validity and temporal stability of the xerostomia inventory (XI), an 11-item summated rating scale that was developed to enable measurement of the severity of dry mouth symptoms in epidemiologic and clinical studies. STUDY DESIGN: A prospective cohort study design was used. Measurements of the severity of dry-mouth symptoms were made with the use of the XI and a standard dry-mouth question ("How often does your mouth feel dry?") on 2 groups of people at baseline, 2, 4, and 6 months. The 2 groups were chosen for their differing symptom trajectories: the onset group (N = 57) comprised patients who were about to undergo radiotherapy for head and neck cancer; and the normal group (N = 55) was a convenience sample of middle-aged and older individuals who were not expected to undergo changes in mouth dryness over the study period. RESULTS: The sex distributions of the 2 groups were similar, but the onset group was younger than the normal group overall. Baseline XI scores were higher among the onset group. The mean XI scores of the normal group did not differ over the observation period, indicating acceptable temporal stability of the XI. The scores of the onset group showed a substantial increase between baseline and 2 months, after which the 2-month level was sustained over the remainder of the study period. That these patterns were mirrored in the percentage responding "frequently" or "always" to the standard question provided further evidence for the concurrent validity of the XI. Linear regression was used to estimate the difference between the final scores after adjusting for age, sex, and initial difference in scores between the 2 groups. This was found to be 9.17 (95% CI 6.24, 12.10) and confirmed that undergoing radiotherapy for head/neck cancer was associated with a substantial increase in the severity of xerostomia symptoms. CONCLUSION: The xerostomia inventory appears to be a valid multi-item method for measuring the severity of the symptoms of dry mouth in clinical and epidemiologic studies.

Adult↗