The Effect of Tomographic Angles on the Osteophytic Lesion Detectability of the Mandibular Condyle / 대한구강악안면방사선학회지

ABSTRACT

PURPOSE: To find out the effects that different tomographic angles have on the osteophytic lesion detectability of condyle head by comparison the individualized lateral tomographic image with the various tomographic angled images using SCANORA . MATERIALS AND METHODS: This study is performed to simulate osteophytic lesions by a series of dentin chips placed at six locations on condyle head. The control angle is 15 and from this angle, tomographic angle were varied with -10 , +10 , +20 . All the images with each sized dentin chip were scored by three dental radiologists with the use of confidence levels for presence or absence of the lesion, each examiner viewed one of the images twice. A rating scale from 0 to 2 (0, lesion definitely not present; 1, uncertain if lesion is present; 2, lesion definitely present). Responses were assessed by Tukey's multiple comparison method and kappa value. RESULTS: 1. The lesion size of 0.3 mm could not be detected in all the tomographic angles. As the size of the lesion increased the average value of lesion detectability also increased. Therefore the average value for the lesion size of 2.0 mm was the highest in every angle. 2. In the leson sizes of 0.7 mm there was statistically significant difference between the 15 control angle and the altered tomographic angles (p0.05), but there was significant difference in the +20 altered angle (p0.05). 3. In the medial, superocentral, lateral area of the condyle there was no significant difference between the 15 control angle and all the altered angles (p>0.05). In the anteromedial, anterosuperior, anterolateral area there was no significant difference between the 15 control angle and the 10 altered angle (p>0.05), but in the comparison with the +20 alterd angle there was significant difference (p<0.05). CONCLUSION: When imaging the lateral tomography of the temporomandibular joint used by SCANORA , it can be considered that in the osteophytic lesion size of 2 mm and above, the tomographic angle difference within +20 to the horizontal angle of the condyle, has little effect on the lesion detectability. And in the lesion size of 1 mm, the altered angle within 10 also has little effect on the lesion detectability.