Onlay grafts used in combination with endosseous implants in severe mandibular atrophy : One year results of a prospective radiological study

Aim of the study

To study the stages of osseous remodelling during the first year following osseous onlay grafts used in association with the placement of implants in the anterior mandible.

Materials and methods

Eight fully edentulous patients with severe mandibular atrophy received cortico-cancellous grafts of iliac bone. Grafts were placed in the anterior part of the mandible together with two endosseous implants destined to assist stabilisation of a complete denture with a Dolder bar. Densitometry of the remodelling bone was undertaken by standardised cephalometric radiographs (OLCR).

Results

During the first 6 months there was a reduction in radiographic density of the cortical part of the graft, accompanied by a 25 % reduction in its height (without demineralisation of the cancellous component). During the second period of 6 months there was an increase in the radiographic density in the basal cancellous part of the graft.

Conclusion

The standardized radiographic system used (OLCR) allowed simultaneous, objective, quantitative evaluation of the cortical and cancellous onlay grafts of iliac bone in cases of mandibular atrophy. The authors discuss the effect of early loading on the resorptive phase.

Commentaries

It would be interesting to know the effect of the origin of the grafts (symphyseal bone, parietal), the number of implants that were loaded (earlier or later) and the design of the implant-supported prosthesis, on the kinetics of bone remodelling.