A historical note on the aetiology of phossy jaw shows that present-day knowledge is little greater than it was a century ago. The varied clinical course of the disease is described together with a report of 10 classical cases not previously reported. Six cases, not amounting to true necrosis but in which healing after dental extraction was delayed, and described, and mention is made of the noticeable differences in the oral state and appearances of tartar of healthy workmen exposed to phosphorus compared with healthy workmen not exposed. But no systematic differences of any kind were found in the incidence of general infections, fractures of bones, haematological findings, and biochemical studies of blood and urine in two groups of healthy men most exposed and least exposed to phosphorous in the same factory. An intensive study in hospital of a case of classical necrosis showed no departure from normal, except delayed healing following bone biopsy from the iliac crest, and a reversed polymorphonuclear/lymphocyte ratio.

In the discussion the time of onset of necrosis after first exposure to phosphorus, clinical and radiological diagnosis, the organisms present, personal susceptibility, the appearance of the sequestra, and regeneration of bone are considered. An up-to-date note on prevention of the disease is given, although this has met with only partial success. Some persons are highly susceptible and, whilst complete protection is impossible in the light of our present knowledge, early diagnosis and modern treatment have robbed the disease of its terrible manifestations of Victorian times and turned it into a minor, although often uncomfortable complaint, with little or no resulting disability.