Blood lead level and dental caries in school-age children.

The association between blood lead level and dental caries was evaluated in cross-sectional analyses of baseline data for 543 children 6-10 years old screened for enrollment in the Children's Amalgam Trial, a study designed to assess potential health effects of mercury in silver fillings. Approximately half of the children were recruited from an urban setting (Boston/Cambridge, MA, USA) and approximately half from a rural setting (Farmington, ME, USA). Mean blood lead level was significantly greater among the urban subgroup, as was the mean number of carious tooth surfaces. Blood lead level was positively associated with number of caries among urban children, even with adjustment for demographic and maternal factors and child dental practices. This association was stronger in primary than in permanent dentition and stronger for occlusal, lingual, and buccal tooth surfaces than for mesial or distal surfaces. In general, blood lead was not associated with caries in the rural subgroup. The difference between the strength of the associations in the urban and rural settings might reflect the presence of residual confounding in the former setting, the presence of greater variability in the latter setting in terms of important caries risk factors (e.g., fluoride exposure), or greater exposure misclassification in the rural setting. These findings add to the evidence supporting a weak association between children's lead exposure and caries prevalence. A biologic mechanism for lead cariogenicity has not been identified, however. Our data are also consistent with residual confounding by factors associated with both elevated lead exposure and dental caries

Manipulation or Mobilisation for Neck Pain

Background Manipulation and mobilisation are often used, either alone or combined with other treatment approaches, to treat neck pain. Objectives To assess if manipulation or mobilisation improves pain, function/disability, patient satisfaction, quality of life, and global perceived effect in adults with acute/subacute/chronic neck pain with or without cervicogenic headache or radicular findings. Search strategy CENTRAL (The Cochrane Library 2009, issue 3) and MEDLINE, EMBASE, Manual Alternative and Natural Therapy, CINAHL, and Index to Chiropractic Literature were updated to July 2009. Selection criteria Randomised controlled trials on manipulation or mobilisation. Data collection and analysis Two review authors independently selected studies, abstracted data, and assessed risk of bias. Pooled relative risk and standardised mean differences (SMD) were calculated. Main results We included 27 trials (1522 participants). Cervical Manipulation for subacute/chronic neck pain : Moderate quality evidence suggested manipulation and mobilisation produced similar effects on pain, function and patient satisfaction at intermediate-term follow-up. Low quality evidence showed manipulation alone compared to a control may provide short-term relief following one to four sessions (SMD pooled -0.90 (95% CI: -1.78 to -0.02)) and that nine or 12 sessions were superior to three for pain and disability in cervicogenic headache. Optimal technique and dose need to be determined. Thoracic Manipulation for acute/chronic neck pain : Low quality evidence supported thoracic manipulation as an additional therapy for pain reduction (NNT 7; 46.6% treatment advantage) and increased function (NNT 5; 40.6% treatment advantage) in acute pain and favoured a single session of thoracic manipulation for immediate pain reduction compared to placebo for chronic neck pain (NNT 5, 29% treatment advantage). Mobilisation for subacute/chronic neck pain : In addition to the evidence noted above, low quality evidence for subacute and chronic neck pain indicated that 1) a combination of Maitland mobilisation techniques was similar to acupuncture for immediate pain relief and increased function; 2) there was no difference between mobilisation and acupuncture as additional treatments for immediate pain relief and improved function; and 3) neural dynamic mobilisations may produce clinically important reduction of pain immediately post-treatment. Certain mobilisation techniques were superior. Authors' conclusions Cervical manipulation and mobilisation produced similar changes. Either may provide immediate-or short-term change; no long-term data are available. Thoracic manipulation may improve pain and function. Optimal techniques and dose are unresolved. Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimat