The delivery of orthodontic care in New Zealand. Part I: Analysis of a census of orthodontists.

A two-part study was undertaken to determine the supply of orthodontic services in New Zealand. Part I focuses on services supplied by specialist orthodontists. A companion paper will describe the amount and characteristics of orthodontic services supplied by dentists. All orthodontists in New Zealand in 1999 were surveyed to provide information on practice location and days practiced in 1996 (the year of the last population Census), and the amount and type of orthodontic treatment carried out in the year 1 July 1998 to 30 June 1999. The response rate was 78.9 percent. Data from 1996 were used to establish and quantify the location and distribution of orthodontists in New Zealand, and their spatial relationship to 12-year-olds and 10- to 14-year-olds using Geographic Information Systems. The information from 1998-1999 was used to determine the amount and variety of services provided by orthodontists and the makeup of their patient base. Nearly two-thirds of orthodontists had a branch practice. Over 50 percent of the 10- to 14-year-old population resided within 5 km of an orthodontist, and nearly three-quarters within 10 km. Disparities between regions existed in the supply of specialist orthodontic services. The catchment areas of main urban areas had more than three times the supply of orthodontists to 12-year-olds than did the secondary and minor urban areas combined. The mean average active patient load was 371, and the mean number of full upper and lower fixed appliances placed was 130.3 during the year of the study. Nearly half of all patients had been referred from dentists, approximately one-quarter were self-referred, and a quarter had been referred by dental therapists. Adults comprised 12.1 percent of the patient load of orthodontists; 60 percent were female.

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.