An epidemiological study of alendronate-related osteonecrosis of the jaws. A case series from the south-east of Scotland with attention given to case definition and prevalence.

A close case study series of alendronate-associated osteonecrosis of the jaws (AONJ) is presented. A consistency of case definition with a minimal reporting requirement was attempted as recommended by the task force of the American Society for Bone and Mineral Research. A hierarchy of evidence focussing on 7 categories of interest was included for each case. A further 7 categories were added by the authors and completed where possible. The patients were drawn from a discrete population of 900,000 from the south-east of Scotland. The prescribing of drugs to this population was monitored by a government agency, the Information Services Office of the National Health Service of Scotland. The daily or weekly standard doses of alendronate prescribed to this population were recorded, thus allowing a calculation of the drug patient years (DPYs). The number of cases of AONJ, when computed against the cumulative year-on-year DPYs for alendronate, suggests an incidence of AONJ per DPYs of <0.004% for age-related or hormone-related osteoporosis. This increased to >0.1% when alendronate was prescribed as a prophylaxis against glucocorticosteroid-induced osteoporosis.