farmdoc's blog post number 599

This month marks 40 years since I graduated as a doctor. Yet only in recent years have the medical journals, and thus the general media, mentioned the causal link between air travel and deep vein thrombosis/pulmonary embolism. More than likely there are multiple reasons for this recency. This review article in the December issue of Australian Prescriber mentions some of them: Aeroplane factors (longer flights, more cramped seating and aisles) and passenger factors (more people flying, more people flying frequently, more overweight people, more people with pre-existing health problems). The article also says four hours is the threshold flight duration; the effectiveness of the airlines’ currently recommended leg exercises is unproven; aspirin is useless in prevention; and the risk of significant thrombosis is greatest at flight’s end and doesn’t return to normal until 2-4 weeks later. Risk, and thus recommended prevention, is divided into low, moderate and high. It all a bit scary. The good news is that short flights (e.g. between Melbourne and Launceston) are risk free. And even on long flights, the incidence is one clinical episode per 4,500 flights – which is low given the number of passengers on 4,500 flights. But it pays to be careful, I think.

farmdoc's blog post number 422

The fluoridation of Melbourne’s water supply began in February 1977 [1]. Until then, dental decay was ubiquitous and severe in Melbourne. I know. My many amalgam and porcelain fillings are testament to the fact I was almost 30 years old in February 1977. I’ll bet you anything no Melburnian born after February 1977 has anywhere near the number of fillings I have. Also important in the prevention of dental decay and periodontal disease is oral hygiene. This short article by periodontist Christopher Daly, in the June 2009 issue of Australian Prescriber, is relevant and interesting. He writes that mechanical procedures are the mainstay of good oral hygiene; because they splay, only soft-bristled toothbrushes should be used; small-headed toothbrushes are preferred because they more easily access the more inaccessible places (most people don’t effectively clean the inner surfaces of the their lower teeth); brushing should be twice per day; two minutes is the optimum duration for plaque removal; toothbrush wear doesn’t impede plaque removal; no one brushing technique’s more effective than the others; toothpaste’s unnecessary for plaque removal but it delivers fluoride; gum massage doesn’t prevent gum disease; once-daily cleaning between the teeth with floss or preferably an interdental brush is needed; the aim is to wipe the interdental tooth surfaces; interdental woodsticks are ineffective; and plaque also forms on denture surfaces.