Functional load in oblique bicortical implants: parasinusal implants and palatine implants.

The history of intraosseous implantology, as a whole, begins with the introduction of the Formiggini screw. Single-piece implants were subsequently derived from titanium bars. The intrinsic function of the emerging stump was immediate loading. The great stability of the implant in the bone thus demanded was eventually achieved by means of the self-tapping screw and bicortical support. Oblique implants were subsequently adopted to make the best use of the bone available and to avoid zones at risk, such as the maxillary sinus and the inferior alveolar nerve. Angled stumps on osseointegrated 2-stage implants were also described in the literature. There has since been a switch from sunken to single-stage implants in view of the usefulness of immediate loading. Recent articles have illustrated the use of inclined, nonbicortical implants; these are still placed in the spongy bone.