Dental implants serve as an excellent replacement for missing teeth. The roots of the posterior teeth in the upper jaw are in close proximity to spaces in the skull called "sinuses" or the "nasal passages". The height of the bone from the sinus is often less than 8 mm, which is insufficient for placement of implants, whose average length ranges from 8 to 13 mm. If an implant were to be placed in these conditions its upper portion would protrude into the sinus space and be devoid of bone coverage. It is, therefore, necessary to perform here what is called a "sinus lift", which consists of filling the underlying space with a bone substitute prior to placing the implant. In the lower jaw, the main limiting factor is a canal containing nerves and blood vessels and which passes in close proximity to the root tips of the teeth. In cases where the height of the bone extending from the nerve canal is under 8 mm or where the thickness of bone is under 4 mm (implants are typically 3.75 mm in diameter) it will be necessary to build more bone, either in the horizontal or vertical plane. This procedure is called "bone augmentation".