The reliability of apical x-ray pictures in the diagnosis of mandibular bone lesions. A review of the literature and in-vitro study

Using 6 macerated human anatomical preparations of mandibular jaw regions with either front teeth or premolars and molars, the radiological detectability of artificial periapical bone lesions was evaluated in relation to the size of the lesions and to the angle of x-ray projection. The artificial lesions were enlarged stepwise until distinct radiological visibility was attained. For each step of enlargement, x-ray pictures were taken with orthoradial as well as with at 25 degrees mesially and distally excentered projections. All x-ray pictures were evaluated by 6 dentists. The following results were obtained: The size of a periapical bone lesion, at which it is becoming radiologically detectable, varies between the different regions of the lower jaw. Isolated spongiosa lesions being larger than 3 mm in diameter are most often detectable at mandibular front teeth and premolars. Isolated spongiosa lesions at mandibular molars are generally non-detectable. Atypical lesions, e.g. discontinuities of bony structures are particularly difficult to detect radiologically. There were no statistically significant differences in lesion detectability between x-rays of different angle projections.