An investigation into the response of palatally displaced canines to the removal of deciduous canines and an assessment of factors contributing to favourable eruption.

The effect of the removal of deciduous canines on palatally displaced maxillary canines was assessed and factors contributing to a successful outcome were analysed. Thirty-nine consecutive patients of mean age 11.2 years (standard deviation 1.43), with 47 palatally displaced canines were included in the study. The cases were examined clinically and radiographically for a maximum period of 2 years following deciduous canine removal. Twenty-nine (62 per cent) of the 47 ectopic canines achieved a normal eruptive position and nine (19 per cent) showed some improvement in eruptive position. The outcome of the removal of the deciduous canine depended on the position of the permanent canine. Horizontal overlap of the nearest incisor was found to be the most significant factor. If this exceeded half the tooth width, success was unlikely. The presence of crowding was found to affect adversely the favourable eruption of the canine. Discriminant analysis was carried out to try to identify clinical features which could act as prognostic indicators for the outcome of deciduous canine removal.