Bone augmentation: split osteotomy (split ridge technique)
Split ridge and expansion techniques are effective for the correction of moderately resorbed edentulous ridges in selected cases. Transverse expansion is based on osseous plasticity obtained by corticotomy. It progressively allows for an adequate transversel intercortical diameter large enough to insert one or several dental implants. The gap created by sagittal osteotomy expansion undergoes spontaneous ossification, following a mechanism similar to that occurring in fractures (Fig. 40.1).
Products and Devices
Various ridge splitting/expanding chisels (from 3 mm to 6 mm) are designed to define the appropriate shape and size of the osteotomy (Fig. 40.2). Ultrasonic units may facilitate and improve the safety of the procedure.
Technical Procedure (Fig. 40.3)
- Full-thickness crestal incision with vertical releasing incisions one tooth further than the site being treated.
- Elevation of a mucoperiosteal flap palatally and buccally to expose the bone ridge.
- Lamellar cortical splitting is initiated by one horizontal crestal osteotomy using a diamond disk, a bur or, preferably, a piezosurgery tip. The longitudinal split can be limited by placing transverse cuts in the bone. Two additional vertical cuts, 2 mm distal to the site of implantation and 1 mm mesial to the adjacent teeth, can be performed to facilitate the expansion.