The use of removable orthodontic appliances in the General Dental Service.

One hundred and fifty removable appliance cases consecutively sampled by the Scottish Dental Practice Board were analysed using the PAR index. The cases were assessed as being suited or unsuited to the removable appliance approach based on the presenting features previously shown to be effectively treated by removable appliances. Using chi-squared tests of association, suitable cases were characterised as being in the mixed dentition, had one feature treated and one appliance used. Suitable cases on average showed 3-4 PAR points more improvement as a result of treatment than equivalent unsuitable cases; regression equations are given. Because of the wide variability within the sample it proved impossible to predict accurately the expected duration of treatment in the General Dental Service.