The delivery of orthodontic care in New Zealand. Part II: Analysis of a census of dentists.

Part I of this study reported the level and distribution of the supply of specialist orthodontic services in New Zealand. This paper focuses on the amount and variety of orthodontic services supplied by dentists. A questionnaire sent to all dentists in New Zealand sought information on the amount and type of orthodontic treatment carried out between 1 July 1998 and 30 June 1999. The reply rate was 80.9 percent. The majority of dentists carried out some form of orthodontic treatment, predominantly of a minor nature. A small number provided significant amounts of treatment, both simple and complex. The majority of orthodontic treatment and the majority of comprehensive fixed-appliance treatment were undertaken by orthodontists. One-quarter of all orthodontic patients in New Zealand were treated by dentists, irrespective of the complexity of treatment. Nearly a fifth of all full fixed upper and lower appliances, and nearly a third of all single-arch fixed appliances were placed by dentists during the study period. In general, male dentists, dentists over the age of 40, those who had attended an orthodontic continuing education course in the previous 5 years, and those who referred fewer patients to an orthodontist carried out more procedures, including those of a complex nature; they also had a higher average active orthodontic patient load. Wanting to be more or less busy had little influence on the amount or complexity of treatment performed. Dentists in regions with a low supply of specialist orthodontic services provided more comprehensive fixed appliance treatment and had a higher orthodontic patient load. However, the presence or absence of an orthodontist in an urban area seemed to have little impact on the complexity of treatment or the orthodontic patient load of dentists. Despite fewer orthodontists in secondary and minor urban areas, dentists in these areas did not have a higher orthodontic patient load, but carried out a wider range of procedures and more complex procedures than those in main urban areas.