The objective of this study was to compare the grade of radiographic sclerosis between the area of osteonecrosis and the at-risk contralateral mandibular area without osteonecrosis. Three groups were studied: group 1 comprised 30 cases of medication-related osteonecrosis of the jaws (MRONJ); group 2 was the healthy contralateral area without osteonecrosis of the group 1 cases; group 3 comprised 30 healthy controls. ImageJ software was used to analyze the computed tomography images, and the grade of bone sclerosis was compared between the three groups. The grade of sclerosis was significantly higher in group 1 than in the other groups (P<0.05); the difference between groups 2 and 3 was not significant. Sclerosis was significantly greater in the area of bone necrosis than in the contralateral mandibular area in patients with MRONJ. No significant differences were found in the grade of sclerosis between the contralateral non-affected mandibular area of patients with MRONJ and the control patients. [Publisher abstract].