Changes in the bone mineral content (BMC) of edentulous mandibles with osseointegrated ITI implants supporting overdentures were measured in vivo by dual-photon absorptiometry. The BMC measurements were performed 3 weeks postoperatively and at the 2-year follow-up visit. Measurements were made in the ITI site (anteriorly), the premolar region just behind the fixtures, and the standard site of the mandible for obtaining reference values of the age-related MBC loss. The increased function of the mandible after this treatment seems to cause a load-related bone formation that minimizes, or in some cases may counteract, the physiologic age-related BMC loss leading to osteoporosis.