Skeletal Site-Specific Response of Jawbones and Long Bones to Surgical Interventions in Rats Treated with Zoledronic Acid

Figure 5

Schematic illustration of known and putative differences of BPs effect on long bones and jawbones. BT: bone turnover; OC: osteoclast; OB: osteoblast. Femur and mandible show relatively lower bone turnover rate than maxilla. The activity of osteoclasts is inhibited which lead to inhibition of osteoblasts activity under BPs treatment. This further results in abnormally high bone density and increased stress in the bone tissue. During healing process of microdamage, more spongy bone and woven bone are formed and slowly mature into lamellae, which lead to femur fracture. Same as with femur situation, jawbones also bear the increased stress in bone tissue, and mandible is likewise a stress-bearing anatomy. However, different from femur, jawbones succumb to ONJ under BPs treatment. Factors such as infection and oral diseases may play a more crucial role in the site-specific character of MRONJ.