measurements specific to implant placement

The critical measurements specific to implant placement include the following:
1. At least 1 mm inferior to the floor of the maxillary and nasal sinuses
2. Incisive canal (maxillary midline implant placement) to be avoided
3. Five millimeters anterior to the mental foramen
4. Two millimeters superior to the mandibular canal
5. Three millimeters from adjacent implants
6. One and one half millimeters from the roots of the adjacent teeth
CT and CBCT image data files can be reformatted and viewed on computers using simulation software. This allows the diagnosis and treatment planning processes to be more accurate with regard to the measurements and
dimensions. Critical anatomic structures can be visualized in all 3 coordinate axes, allowing their superior to inferior, anterior to posterior, and buccal to lingual locations to be identified. These measurements are extremely
important when planning whether and exactly where implants can be placed (Fig III-2).

FIGURE III-2. Cone-beam computed tomography scan allowing the visualization of multiple structures in
3 dimensions. Top left, The coronal slice through the posterior edentulous area demonstrating the anatomy of
the maxillary sinus and alveolar ridge bone. Top right, A cross-sectional view of an edentulous anterior maxillary
ridge. Bottom left, An axial view showing the deficiency of the anterior maxillary ridge. Bottom right,
3-dimensional reconstruction.