Accuracy in the diagnosis of mandibular involvement by oral cancer.

Cancer of the mandibular region usually has a poor prognosis; this is particularly correlated to invasion of the mandible. To reduce the consequences of poor therapeutic planning, careful preoperative assessment of bone infiltration is necessary. We have examined the records of 50 patients evaluated by clinical examination, conventional radiography, computed tomography (CT), bone scintigraphy with 99mTc and magnetic resonance imaging (MRI). The highest sensitivity (100\%) was attained by scintigraphy; the highest values of specificity (96.3\%) were reached by CT scan and MRI. A CT scan showed the highest predictive positive value (95.4\%) and efficiency (94\%), this plus MRI have good values and the associated sensitivity and efficiency are higher than when these techniques are used alone.