No discomfort was experienced by patients when the examination was performed using the probe, either internally or externally. Images of the periradicular lesions were obtained and identified in all the cases using both the intraoral and extra-oral technique. Based on the descriptive chart, the radiographic images were able to describe the lesions and their relationship with anatomical landmarks in two dimensions, but did not provide information as to their size and content. The echotomograms showed the lesion within the bone in three dimensions, and their content in terms of fluids or tissue and blood vessels (at colour/power Doppler). In the echotomograms it was also possible to obtain a precise measure of the diameters of the lesions, whilst it was not possible to constantly identify any anatomical reference points (i.e. specific teeth).
The echographic study showed the presence of six lesions which were frankly transonic (hypoechoic) and therefore could be interpreted as cavities filled with fluids. These cavities had well defined contours and no evidence of vascularization at the colour-power/Doppler control (Figs 1, 2). The remaining six lesions exhibited a rounded shape only partially defined. In two of the cases an interruption of the bone profile was observed mesially; the echostructure of these lesions showed a content which was in part hypoechoic and in part corpuscolated ( Figs 3, 4).
Figure 1. Panoramic radiograph with a lesion involving the periradicular area of teeth 32, 33 and 34 (arrowed).
Figure 2. Echotomogram (ultrasound image) of the lesion in Fig. 1, showing a 'transonic lesion' (arrowed) with well defined and reinforced contours (arrowed).
Figure 3. Panoramic radiograph with a lesion (arrowed) in the periradicular area corresponding to tooth 44 (fractured root).
Figure 4. Echotomogram (ultrasound image) of the lesion in Fig. 3 (framed) with partially transonic (fluid filled) content (arrowed) and partially corpuscolated with rich vascularization (coloured).
Figure 5. Panoramic radiograph with a lesion (arrowed) in the periradicular area corresponding to tooth 45.
Figure 6. Echotomogram (ultrasound image) of the same lesion in Fig. 5 (framed): an echogenic content, partially defined contours (arrowed), and an intralesion vascular supply (coloured) are visible.
The content of the other four lesions was frankly echogenic (hyperechoic); (Figs 5, 6). With colour-power- Doppler examination all these six lesions showed a rich vascularization ( Figs 4, 6).