Objective: This study examined the question of taking anterior occlusal radiographs (AO) in addition to a dental panoramic tomogram (DPT) using the Planmeca PM Proline CC.
Design: Retrospective single centre study.
Setting: Dental hospital radiology department.
Subjects: 100 pairs of DPTs and AOs which had been requested for orthodontic assessment were examined between April and July 1995. All DPTs were taken on a Planmeca PM Proline CC machine.
Results: The AO was assumed to be the gold standard and the diagnostic validity of the DPT can be assessed using values of sensitivity and specificity. 21% of DPTs were identified as requiring a supplementary radiograph to clarify the image of the anterior maxilla.
Conclusions: A DPT machine with an adjustable focal trough has significantly reduced the need for supplementary AO radiographs. The AO is indicated when there is abnormality in the premaxilla or where dental malocclusion prevents ideal positioning of the patient in the machine.