Tc-99m-polyphosphate bone imaging of orthodontically treated dog teeth

Abstract

A number of bone lesions are detectable by means of skeletal imaging with injected, short-lived, bone-seeking radiopharmaceuticals. These include osteonecrosis,l> 2 osteoarthritis,3 infectious spondylitis,4 primary5 and metastaticj tumors, fractures,? and osteomyelitis. s High concentrations of radioactivity in surrounding areas of new bone formation *, 5* o facilitate the localization of a lesion with externally placed radiation-measuring devices. Since the method is sensitive to small changes in the rates of local bone formation in the early stages of disease, it can often detect skeletal lesions before they are recognizable on radiographs. This clinical tool, therefore, provides diagnostic information of a metabolic or functional nature. In the present study we have attempted to apply this nondestructive method to a study of metabolic events in alveolar bone supporting orthodontically treated teeth in dogs. The objectives of the study were to determine whether bone-seeking radionuclide methods could (1) provide longitudinal metabolic information through repeated measurements of the same animal, (2) distinguish the effects of orthodontic and orthopedic forces of different magnitudes, and (3) measure separately the metabolic events occurring in areas of pressure and tension. In addition, two different radiation-detection systems were used for the collection of data, and their usefulness as research tools in dentistry was evaluated and compared.