Radiographs associated with one episode of orthodontic therapy.

Obtaining lifetime diagnostic radiation histories in head and neck cancer studies is often challenging due to the almost universal lack of centralized registries on X-ray utilization in medicine and dentistry. Both the common nature of orthodontics and the young age at which orthodontics typically occurs make it important to quantify what diagnostic radiographs are typically taken during orthodontic therapy. The aim of this study was to assess the number and type of radiographic films associated with one episode of orthodontic therapy in an educational setting. Charts stored in an orthodontic clinic at one academic setting were randomly sampled, and the type and number of radiographic examinations were tallied for the 325 individuals who were in orthodontic therapy for at least one year. Being under orthodontic therapy for one or more years was associated with a median number of seven extra-oral radiographs and twenty-four intra-oral radiographic films. The extra-oral radiographs included three panoramic radiographs and three cephalometric radiographs. Less than 10 percent of the variability was explained by factors such as age, gender, calendar year, surgical orthodontic therapy, and duration of therapy. Head and neck cancer etiology studies should take into account the ionizing radiation during episodes of orthodontic care. The substantial variability in radiographic practices in orthodontics could be reduced by research into clinical utility and by establishing guidelines.