The inlay technique in the treatment of posterior mandibular atrophy.

Horizontal osteotomy with the interposition of bone in the form of a “sandwich”, first described by Schettler (1976), is also known as the “inlay technique” or “interpositional bone grafting”. This technique is indicated for the treatment of vertical atrophy in the posterior mandible. The inlay technique involves raising a coronal osteotomised segment of the mandible that is still attached to the lingual periosteum, and interpositioning a bone block graft between the basal bone and the raised osteotomized segment. Frequently, however, the interpositional technique is associated with autologous bone harvesting which entails discomfort and postsurgical morbidity. Recently, Felice et al. demonstrated that the use of deproteinised bovine bone mineral (DBBM) blocks in the inlay technique yields clinical and histological results similar to the procedure with autologous bone harvesting from the iliac crest. The DBBM inlay technique is technically more straightforward and much less invasive. Unfortunately, the use of a DBBM block is challenged by the extreme fragility of the block. A high risk of breakage has been reported during DBBM block shaping and placement. Due to the presence of collagen, a cancellous equine bone block is more rigid and less fragile than the DBBM block; it can be shaped more easily without breaking and so allows a good vertical increase. As a consequence a collagenated bone block could be considered the best solution for the interpositional technique in the posterior mandible.