AbstractInterproximal bone levels were measured from orthopantograms of a consecutive group of 373 patients who had all their remaining teeth extracted in a dental teaching hospital. There was little periodontal destruction below the age of 40. In older patients (those aged 40 or over) 77% of the teeth had lost at least 25% of their supporting bone. 64% of the older patients had at least one tooth with advanced (more than 50%) bone loss. Only 15% of the patients had generalised advanced periodontal destruction (more than 50% of their teeth with advanced bone loss) at clearance. Men had more periodontal destruction than women. It was concluded that severe periodontal disease was limited to a small proportion of the patients in which it was a major factor in the loss of their dentition. However, in many cases it was doubtful whether the periodontal condition was of any consequence when the decision was taken to remove the remaining natural teeth.