Discussion :
Lateral Sinus floor elevation is one of the most widely used augmentation procedures. It enables implant placement in the posterior region of an atrophic maxilla, where the bone is generally reduced as a result of two phenomenons : alveolar ridge resorption due to increased osteoclastic activity following tooth loss and sinus extention due its pneumatization (11).
While sinus floor elevation by the transalveolar approach is indicated in moderate vertical defects (>= 7mm), the lateral approach is used when facing severe maxillary atrophy (ridge hight <6mm). A minimal residual height of 4mm indicates immediate implant placement, otherwise, the bone quantity would be insufficient to obtain primary stability, and implant surgery must be delayed (table 1) (5).