Helen V Worthington

Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review.

Abstract Objective To review systematically the evidence for an effect of long chain and shorter chain omega 3 fatty acids on total mortality, cardiovascular events, and cancer. Data sources Electronic databases searched to February 2002; authors contacted and bibliographies of randomised controlled trials (RCTs) checked to locate studies. Review methods Review of RCTs of omega 3 intake for 3 6 months in adults (with or without risk factors for cardiovascular disease) with data on a relevant outcome. Cohort studies that estimated omega 3 intake and related this to clinical outcome during at least 6 months were also included. Application of inclusion criteria, data extraction, and quality assessments were performed independently in duplicate. Results Of 15 159 titles and abstracts assessed, 48 RCTs (36 913 participants) and 41 cohort studies were analysed. The trial results were inconsistent. The pooled estimate showed no strong evidence of reduced risk of total mortality (relative risk 0.87, 95% confidence interval 0.73 to 1.03) or combined cardiovascular events (0.95, 0.82 to 1.12) in participants taking additional omega 3 fats. The few studies at low risk of bias were more consistent, but they showed no effect of omega 3 on total mortality (0.98, 0.70 to 1.36) or cardiovascular events (1.09, 0.87 to 1.37). When data from the subgroup of studies of long chain omega 3 fats were analysed separately, total mortality (0.86, 0.70 to 1.04; 138 events) and cardiovascular events (0.93, 0.79 to 1.11) were not clearly reduced. Neither RCTs nor cohort studies suggested increased risk of cancer with a higher intake of omega 3 (trials: 1.07, 0.88 to 1.30; cohort studies: 1.02, 0.87 to 1.19), but clinically important harm could not be excluded. Conclusion Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.

The efficacy of horizontal and vertical bone augmentation procedures for dental implants - a Cochrane systematic review.

BACKGROUND dental implants require sufficient bone to be adequately stabilised. For some patients implant treatment would not be an option without horizontal or vertical bone augmentation. A variety of materials and surgical techniques are available for bone augmentation. OBJECTIVES to test whether and when augmentation procedures are necessary and which is the most effective technique for horizontal and vertical bone augmentation. SEARCH METHODS the Cochrane Oral Health Groups Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. Several dental journals were hand searched. The bibliographies of review articles were checked, and personal references were searched. More than 55 implant manufacturing companies were also contacted. The last electronic search was conducted on 11 June 2009. SELECTION CRITERIA randomised controlled trials (RCTs) of different techniques and materials for augmenting bone horizontally and/or vertically for implant treatment that reported the outcome of implant therapy at least to abutment connection. Trials were divided into two broad categories: horizontal augmentation and vertical augmentation techniques. DATA COLLECTION AND ANALYSIS screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and odds ratios (OR) for dichotomous outcomes with 95% confidence intervals (CI). The statistical unit of the analysis was the patient. RESULTS 13 RCTs out of 18 potentially eligible trials were suitable for inclusion. Three RCTs (106 patients) dealt with horizontal and 10 trials (218 patients) with vertical augmentation. Since different techniques were evaluated in different trials, only one meta-analysis could be performed. When comparing whether vertical augmentation procedures were more advantageous than short implants, a meta-analysis of two trials resulted in more implant failures OR = 5.74 (95% CI 0.92 to 35.82; borderline significance, P = 0.06) and statistically significantly more complications OR = 4.97 (95% CI 1.10 to 22.40) in the vertically augmented group. When comparing various horizontal augmentation techniques (three trials) no statistically significant differences were observed. When comparing various vertical bone augmentation techniques (eight trials) no statistically significant differences were observed except for three trials which showed that more vertical bone gain could be obtained with osteodistraction than with inlay autogenous grafts (mean difference 3.25 mm; 95% CI 1.66 to 4.84), and with bone substitutes rather than autogenous bone in guided bone regeneration (mean difference 0.60 mm; 95% CI 0.21 to 0.99) in posterior atrophic mandibles, and that patients preferred a bone substitute block over a block of autogenous bone taken from the iliac crest (OR = 0.03; 95% CI 0.00 to 0.64; P = 0.02). CONCLUSIONS conclusions are based on few trials including few patients, sometimes having a short follow-up, and often being judged to be at high risk of bias. Various techniques can augment bone horizontally and vertically, but it is unclear which are the most efficient. Short implants appear to be a better alternative to vertical bone grafting of resorbed mandibles. Complications, especially for vertical augmentation, are common. Some bone substitutes could be a preferable alternative to autogenous bone. Osteodistraction osteogenesis allows for more vertical bone augmentation than other techniques, which, on the other hand, can allow for horizontal augmentation at the same time. Titanium screws may be preferable to resorbable screws to fixate onlay bone grafts.

The design and analysis of split‐mouth studies: What statisticians and clinicians should know

The split-mouth design is a popular design in oral health research. In the most common split-mouth study, each of two treatments are randomly assigned to either the right or left halves of the dentition. The attractiveness of the design is that it removes a lot of inter-individual variability from the estimates of the treatment effect. However, already about 20 years ago the pitfalls of the design have been reported in the oral health literature. Yet, many clinicians are not aware of the potential problems with the split-mouth design. Further, it is our experience that most statisticians are not even aware of the existence of this design. Since most of the critical remarks appeared in the oral health literature, we argue that it is necessary to introduce the split-mouth design to a statistical audience, so that both clinicians and statisticians clearly understand the advantages, limitations, statistical considerations, and implications of its use in clinical trials and advise them on its use in practice.

Cochrane Reviews on the Benefits/Risks of Fluoride Toothpastes:

This concise review presents two Cochrane Reviews undertaken to determine: (1) the relative effectiveness of fluoride toothpastes of different concentrations in preventing dental caries in children and adolescents; and (2) the relationship between the use of topical fluorides in young children and their risk of developing dental fluorosis. To determine the relative effectiveness of fluoride toothpastes of different concentrations, we undertook a network meta-analysis utilizing both direct and indirect comparisons from randomized controlled trials (RCTs). The review examining fluorosis included evidence from experimental and observational studies. The findings of the reviews confirm the benefits of using fluoride toothpaste, when compared with placebo, in preventing caries in children and adolescents, but only significantly for fluoride concentrations of 1000 ppm and above. The relative caries-preventive effects of fluoride toothpastes of different concentrations increase with higher fluoride concentration. However, there is weak, unreliable evidence that starting the use of fluoride toothpaste in children under 12 months of age may be associated with an increased risk of fluorosis. The decision of what fluoride levels to use for children under 6 years should be balanced between the risk of developing dental caries and that of mild fluorosis.

Early treatment for Class II Division 1 malocclusion with the Twin-block appliance: a multi-center, randomized, controlled trial.

INTRODUCTION The aim of this study was to evaluate the effectiveness of early orthodontic treatment with the Twin-block appliance for the treatment of Class II Division 1 malocclusion. This was a multi-center, randomized, controlled trial with subjects from 14 orthodontic clinics in the United Kingdom. METHODS The study included 174 children aged 8 to 10 years with Class II Division 1 malocclusion; they were randomly allocated to receive treatment with a Twin-block appliance or to an initially untreated control group. The subjects were then followed until all orthodontic treatment was completed. Final skeletal pattern, number of attendances, duration of orthodontic treatment, extraction rate, cost of treatment, and the childs self-concept were considered. RESULTS At the end of the 10-year study, 141 patients either completed treatment or accepted their occlusion. Data analysis showed that there was no differences between those who received early Twin-block treatment and those who had 1 course of treatment in adolescence with respect to skeletal pattern, extraction rate, and self-esteem. Those who had early treatment had more attendances, received treatment for longer times, and incurred more costs than the adolescent treatment group. They also had significantly poorer final dental occlusion. CONCLUSIONS Twin-block treatment when a child is 8 to 9 years old has no advantages over treatment started at an average age of 12.4 years. However, the cost of early treatment to the patient in terms of attendances and length of appliance wear is increased.

A Cluster-randomized Controlled Trial: Fluoride Varnish in School Children

We conducted a school-based parallel cluster randomized controlled trial with 36-month follow-up of children aged 7 to 8 years. Primary schools were randomly assigned to 2 groups: 3 applications of fluoride varnish (22,600 ppm) each year or no intervention. The primary outcome was DFS increment in the first permanent molars, with the hypothesis that 9 applications of varnish over 3 years would result in a lower increment in the test group. Follow-up measurements were recorded by examiners blind to the allocation. Ninety-five schools were randomized to the test and 95 to the reference groups; 1473 (test) and 1494 (reference) children participated in the trial. An intention-to-treat analysis was carried out with random effects models. The DFS increment was 0.65 (SD 2.15) in the test and 0.67 (SD 2.10) in the reference groups, respectively. There was no statistically significant difference between the groups. We were unable to demonstrate an effect for fluoride varnish when it was used as a public health intervention to prevent caries in the first permanent molar teeth (Inter-national Standard Randomized Controlled Trial Registration: ISRCTN: #72589426)

Pharyngeal flap and sphincterplasty for velopharyngeal insufficiency have equal outcome at 1 year postoperatively: Results of a randomized trial

Objective The aim of this trial was to compare the relative effectiveness (efficacy and morbidity) of two surgical procedures for correcting velopharyngeal insufficiency (VPI). Design This was an international multicenter randomized trial to study the outcome of two surgical procedures (flap and sphincter pharyngoplasty) for speech, incidence of sleep apnea, and surgical complications. Method Ninety-seven patients 3 to 25 years old with repaired cleft palate and previously identified VPI were enrolled from five centers in the United States, Norway, and the U.K. Data were collected at presurgery, 3 months postsurgery, and 12 months postsurgery for subsequent analysis blind to the procedure. Main outcome measures included perceptual speech parameters, sleep apnea, nasalance measures, endoscopic features, and surgical complications. Results Groups for both surgical procedures achieved a high level of clinical improvement. At 3 months postsurgery, elimination of hypernasal resonance was achieved in twice as many patients after the flap procedure. This reached significance. However, at 12 months postsurgery, no statistically significant difference in outcomes remained between the two procedures for resonance, nasalance, endoscopic outcomes, or surgical complications. Flap and sphincter pharyngoplasty rarely resulted in clinically significant sleep apnea, and no difference was detected between the two procedures in the long-term incidence of sleep apnea. Conclusions Despite strongly held views in the literature concerning the relative effectiveness and safety of flap and sphincter pharyngoplasty, no significant differences were detected 1 year postoperatively.

Orofacial pain: just another chronic pain? Results from a population-based survey

&NA; Features of somatisation have been shown to predict the onset of widespread body pain. This study aims to determine to what extent persons with orofacial pain syndromes share these features and to what extent they are uniquely related to oral mechanical factors. We have conducted a population‐based cross‐sectional survey in the South‐East Cheshire area of the United Kingdom involving 2504 individuals aged 18–65 years. All participants completed a postal questionnaire which enquired about the occurrence of both orofacial pain and widespread body pain. It also enquired about potential risk factors for one or both conditions. In total, 473 subjects (23%) reported orofacial pain only, 123 (6%) widespread pain only, while 85 (4%) reported both. The number reporting both was significantly higher than would be expected if the symptoms were independent (P<0.001). Several oral mechanical factors were significantly associated with both orofacial pain and widespread body pain (grinding teeth, clicking jaw, missing teeth), while two (facial trauma, locking jaw) were specifically related to orofacial pain. Both pain syndromes were associated equally with high levels of psychological distress, indicators of somatisation and maladaptive response to illness. These results suggest that orofacial pain syndromes may commonly be a manifestation of the process of somatisation and the excess reporting of some local mechanical factors amongst persons with these symptoms, may not be uniquely associated with pain in the orofacial region.

Water fluoridation, poverty and tooth decay in 12-year-old children

AIM To examine the influence of water fluoridation, and socio-economic deprivation on tooth decay in the permanent dentition of 12 year old children. SETTING The North of England, fluoridated Newcastle and non-fluoridated Liverpool. A total of 6,638 children were examined. OUTCOME MEASURES Multiple Regression analysis of fluoride status, mean electoral ward DMFT in 1992/93 and ward Townsend Scores from the 1991 census. RESULTS Social deprivation and tooth decay were significantly correlated in areas with and without water fluoridation. Multiple linear regression showed a statistically significant interaction between ward Townsend score, mean DMFT and water fluoridation, showing that the more deprived the area the greater the reduction in tooth decay. At a Townsend score of zero (the English average) there was a predicted 37% reduction in decay in 12-year-olds in fluoridated wards. CONCLUSIONS Tooth decay is strongly associated with social deprivation. The findings confirm that the implementation of water fluoridation has markedly reduced tooth decay in 12-year-old children and that socio-economic dental health inequalities are reduced.

Orthodontic retention: A systematic review

Objective To evaluate the effectiveness of different retention strategies used to maintain tooth position after treatment by orthodontic appliances. Data sources The search strategy was carried out according to the standard Cochrane systematic review methodology. The following databases were searched for randomized clinical trials (RCT) or controlled clinical trials (CCT): Cochrane Oral Health Group Trials Register, Cochrane Clinical Trials Register, MEDLINE and EMBASE. No language restrictions were applied. Authors of trials were contacted to identify unpublished trials. Inclusion and exclusion criteria were applied when considering the studies to be included and a quality assessment made for each paper. Data selection The primary outcome was the amount of relapse. Secondary outcomes were survival of retainers, adverse effects on oral health and patient satisfaction. Data extraction Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two reviewers. Five studies (2 RCTs and 3 CCTs) fulfilled the inclusion criteria. Data synthesis There was evidence, based on data from one trial, that there was a statistically significant increase in stability in both the mandibular (P<0.001) and maxillary anterior segments (P<0.001) when the CSF (circumferential supracrestal fiberotomy) was used in conjunction with a Hawley retainer, compared with a Hawley retainer alone. However, this evidence may be unreliable due to flaws in the study design. There was also weak, unreliable evidence that teeth settle quicker with a Hawley retainer than with a clear overlay retainer after 3 months. Conclusions There is currently insufficient evidence on which to base the clinical practice of orthodontic retention.