ARE ANTERIOR OCCLUSAL RADIOGRAPHS INDICATED TO SUPPLEMENT PANORAMIC RADIOGRAPHY DURING AN ORTHODONTIC ASSESSMENT

Five hundred pairs of dental panoramic tomographs (DPT) and maxillary anterior occlusal radiographs (AO) from patients referred to the ortho dontic department of a dental teaching hospital were examined to asses s the diagnostic yield from a panoramic radiograph of the premaxillary region alone and then assess the additional yield when this view was supplemented by a maxillary anterior occlusal radiograph. Of the 500 D PTs assessed, 208 (42%) lacked clarity of the premaxillary region when the labial segments were used to locate the patient in the DPT machin e. An association was found between patients who had abnormal incisor relationships and poor clarity in the premaxillary region of the DPT. Overall 165 (33%) of the supplementary AO views were used to support o r refute findings identified on the DPT. It was concluded that in pati ents referred for an orthodontic assessment, supplementary radiography of the premaxilla may be justified in the following situations: 1. un satisfactory image quality which may frequently be the case where ther e are abnormal incisor relationships, 2. localisation of tooth positio n by vertical parallax and 3. where a reasonable expectation that path ology exists on clinical grounds.