Discontinued orthodontic treatment in the general dental services of England and Wales (1990-1991).

Relevant feature of a sample of discontinued treatments were investigated, including status at the start and at the time of discontinuation. In a comparison between two discontinued groups, those patients who simply failed to return tended to have lower pretreatment PAR scores, and were more likely to have received non-extraction treatments in which removable appliances were employed. However, when discontinued treatments were compared to completed treatments undertaken in 1987/8, the completed cases were only reduced by two further PAR points.