P. Finbarr Allen

Interpreting oral health-related quality of life data

The most common way of presenting data from studies using quality of life or patient-based outcome (PBO) measures is in terms of mean scores along with testing the statistical significance of differences in means. We argue that this is insufficient in and of itself and call for a more comprehensive and thoughtful approach to the reporting and interpretation of data. PBO scores (and their means for that matter) are intrinsically meaningless, and differences in means between groups mask important and potentially different patterns in response within groups. More importantly, they are difficult to interpret because of the absence of a meaningful benchmark. The minimally important difference (MID) provides that benchmark to assist interpretability. This commentary discusses different approaches (distribution-based and anchor-based) and specific methods for assessing the MID in both longitudinal and cross-sectional studies, and suggests minimum standards for reporting and interpreting PBO measures in an oral health context.

A cross-national comparison of income gradients in oral health quality-of-life in four welfare states: application of the Korpi and Palme typology

Background: The extent to which welfare states may influence health outcomes has not been explored. It was hypothesised that policies which target the poor are associated with greater income inequality in oral health quality of life than those that provide earnings-related benefits to all citizens. Methods: Data were from nationally representative surveys in the UK (n = 4064), Finland (n = 5078), Germany (n = 1454) and Australia (n = 2292) conducted from 1998 to 2002. The typology of Korpi and Palme classifies these countries into four different welfare states. In each survey, subjects completed the Oral Health Impact Profile (OHIP-14) questionnaire, which evaluates the adverse consequence of dental conditions on quality of life. For each country, survey estimation commands were used to create linear regression models that estimated the slope of the gradient between four quartiles of income and OHIP-14 severity scores. Parameter estimates for income gradients were contrasted across countries using Wald χ2 tests specifying a critical p value of 0.008, equivalent to a Bonferroni correction of p<0.05 for the six pairwise tests. Results: Statistically significant income gradients in OHIP-14 severity scores were found in all countries except Germany. A global test confirmed significant cross-national differences in the magnitude of income gradients. In Australia, where a flat rate of benefits targeted the poor, the mean OHIP-14 severity score reduced by 1.7 units (95% CI −2.15 to −1.34) with each increasing quartile of household income, a significantly steeper gradient than in other countries. Conclusion: The coverage and generosity of welfare state benefits appear to influence levels of inequality in population oral health quality of life.

Determining the minimally important difference for the Oral Health Impact Profile‐20

In the context of clinical trials, measurement of change is critical. The aim of this study was to determine the minimally important difference (MID) for the Oral Health Impact Profile-20 (OHIP-20) when used with partially dentate patients undergoing treatment that included the provision of removable partial dentures. In a prospective clinical trial, 51 consecutive patients were provided with removable partial dentures. In addition to demographic and dental status data, patients completed an OHIP-20 prior to treatment. One month postoperatively, patients completed a post-treatment OHIP-20 and a global transition scale. Domains assessed in the global transition scale were appearance, ability to chew food, oral comfort, and speech. The MID for the OHIP-20 was calculated using the anchor-based approach. From the initial sample of 51 patients, 44 completed post-treatment questionnaires and were included in the analysis. Change scores in the four transition domains indicated that new dentures had a positive impact in the majority of subjects, especially in perceived impact on chewing and appearance. The study provided a guideline as to what constitutes the MID for the OHIP-20. This benchmark can be used when interpreting the impact of clinical intervention for replacing missing teeth and for power calculation in statistical analyses.

The impact of rehabilitation using removable partial dentures and functionally orientated treatment on oral health-related quality of life: a randomised controlled clinical trial.

OBJECTIVES This study aimed to compare two different tooth replacement strategies for partially dentate older patients; namely functionally orientated treatment according to the principles of the shortened dental arch (SDA) and conventional treatment using removable partial dentures (RPDs) using a randomised controlled clinical trial. The primary outcome measure for this study was impact on oral health-related quality of life (OHRQoL) measured using the short form of the oral health impact profile (OHIP-14). METHODS Patients aged 65 years and older were randomly allocated to two different treatment groups: the RPD group and the SDA group. For the RPD group each patient was restored to complete arches with cobalt-chromium RPDs used to replace missing teeth. For the SDA group, patients were restored to a premolar occlusion of 10 occluding pairs of natural and replacement teeth using resin bonded bridgework (RBB). OHRQoL was measured using the OHIP-14 questionnaire administered at baseline, 1 month, 6 months and 12 months after treatment intervention. RESULTS In total, 89 patients completed the RCT: 44 from the RPD group and 45 from the SDA group. Analysis using a mixed model of covariance (ANCOVA) illustrated that treatment according to the SDA concept resulted in significantly better mean OHIP-14 scores compared with RPD treatment (p<0.05). This result was replicated in both treatment centres used in the study. CONCLUSIONS In terms of impact on OHRQoL, treatment based on the SDA concept achieved significantly better results than that based on RPDs 12 months after treatment intervention (trial registration no. ISRCTN26302774). CLINICAL SIGNIFICANCE Functionally orientated treatment delivery resulted in significantly better outcomes compared to removable dentures in terms of impact on OHRQoL.

Two-year survival of ART restorations placed in elderly patients: A randomised controlled clinical trial

OBJECTIVES Older dentate adults are a high caries risk group who could potentially benefit from the use of the atraumatic restorative treatment (ART). This study aimed to compare the survival of ART and a conventional restorative technique (CT) using rotary instruments and a resin-modified glass-ionomer for restoring carious lesions as part of a preventive and restorative programme for older adults after 2 years. METHODS In this randomised controlled clinical trial, 99 independently living adults (65-90 years) with carious lesions were randomly allocated to receive either ART or conventional restorations. The survival of restorations was assessed by an independent and blinded examiner 6 months, 1 year and 2 years after restoration placement. RESULTS Ninety-six (67.6%) and 121 (76.6%) restorations were assessed in the ART and CT groups, respectively, after 2 years. The cumulative restoration survival percentages after 2 years were 85.4% in the ART and 90.9% in the CT group. No statistically significant between group differences were detected (p=0.2050, logistic regression analysis). CONCLUSIONS In terms of restoration survival, ART was as effective as a conventional restorative approach to treat older adults after 2 years. This technique could be a useful tool to provide dental care for older adults particularly in the non-clinical setting. ( TRIAL REGISTRATION NUMBER ISRCTN 76299321). CLINICAL SIGNIFICANCE The results of this study show that ART presented survival rates similar to conventional restorations in older adults. ART appears to be a cost-effective way to provide dental care to elderly patients, particularly in out of surgery facilities, such as nursing homes.

Failure rates of class V restorations in the management of root caries in adults – a systematic review

OBJECTIVE The aim of this systematic review was to compare cumulative failure rates of different restorative materials in carious class V lesions on the root surfaces of adult patients. BACKGROUND The prevalence of root caries is set to increase in the coming years as a result of ageing of the population and a concomitant reduction in levels of edentulousness. Evidence is needed to assist practitioners to select the most appropriate restorative material for use in these lesions. METHODS A search of the literature was undertaken using the electronic databases of PubMed, Embase, CENTRAL and OpenSIGLE using keywords relevant to the search question. Two review authors conducted the electronic search independently, and any conflict was resolved by discussion. The references quoted in the full text articles extracted were hand searched for any further eligible studies. RESULTS Sixty non-duplicate citations were screened. Following review of the titles, abstracts, texts and application of the pre-determined inclusion/exclusion criteria, five studies remained. CONCLUSION There is a need for more research in this area as many of the studies identified in this systematic review treated post-radiation, xerostomic patients which are not typical of the general population. Increased adherence to CONSORT guidelines for reporting is also advised to facilitate future systematic review and meta-analysis in this area.

Comparison of functionally orientated tooth replacement and removable partial dentures on the nutritional status of partially dentate older patients: A randomised controlled clinical trial

OBJECTIVES The aims of this study were to conduct a randomised controlled clinical trial (RCT) of partially dentate older adults comparing functionally orientated treatment based on the SDA concept with conventional treatment using RPDs to replace missing natural teeth. The two treatment strategies were evaluated according to their impact on nutritional status measured using haematological biomarkers. METHODS A randomised controlled clinical trial (RCT) was conducted of partially dentate patients aged 65 years and older (Trial Registration no. ISRCTN26302774). Each patient provided haematological samples which were screened for biochemical markers of nutritional status. Each sample was tested in Cork University Hospital for serum Albumin, serum Cholesterol, Ferritin, Folate, Vitamin B12 and 25-hydroxycholecalciferol (Vitamin D). RESULTS A mixed model analysis of covariance (ANCOVA) indicated that for Vitamin B12 (p=0.9392), serum Folate (p=0.5827), Ferritin (p=0.6964), Albumin (p=0.8179), Serum Total Cholesterol (p=0.3670) and Vitamin D (p=0.7666) there were no statistically significant differences recorded between the two treatment groups. According to the mixed model analysis of covariance (ANCOVA) for Vitamin D there was a significant difference between levels recorded at post-operative time points after treatment intervention (p=0.0470). There was an increase of 7% in 25-hydroxycholecalciferol levels recorded at 6 months compared to baseline (p=0.0172). There was no further change in recorded levels at 12 months (p=0.6482) and these increases were similar within the two treatment groups (p>0.05). CONCLUSIONS The only measure which illustrated consistent significant improvements in nutritional status for either group were Vitamin D levels. However no significant difference was recorded between the two treatment groups. CLINICAL SIGNIFICANCE Functionally orientated prosthodontic rehabilitation for partially dentate older patients was no worse than conventional removable partial dentures in terms of impact on nutritional status.

Impact of resin bonded bridgework on quality of life of patients with hypodontia

OBJECTIVES To determine the impact of hypodontia on the quality of life of adolescent and young adult patients, and, to assess the impact of restoring tooth spaces with resin bonded bridgework on quality of life of patients with hypodontia. METHODS In a prospective study, 82 patients with a confirmed diagnosis of hypodontia participated. The primary outcome was oral health related quality of life (OHRQoL) and this was measured using the OHIP-49 prior to treatment. The pre-treatment sample was then divided into two groups: the test group (n=40 patients) who had completed orthodontic treatment and had tooth spaces restored with resin bonded bridgework, and, a control group (n=42 patients) who were still in the process of orthodontic treatment. All patients completed a follow-up OHIP-49, and between and within group comparisons made. RESULTS The pre-treatment sample included 43 females and 39 males, age ranged from 16 to 34 years (median age 19). Forty-three patients had more than 4 congenitally missing teeth and thirty-nine had ≤ 4 congenitally missing teeth. There were no differences between the groups prior to treatment. For the test group, there was a significant improvement in median OHIP summary scores (p<0.001) after treatment. OHIP scores deteriorated to a significant degree for control subjects (p=0.002). The effect sizes for the pre-post treatment change in both groups were moderate to large. CONCLUSIONS Hypodontia has a significant impact on oral health related quality of life. Provision of resin bonded bridges has a positive impact on oral health related quality of life of patients with hypodontia.