The nasopalatine canal may show important anatomical variations, both with regard to morphology and dimensions. To avoid any potential complications during surgical procedures such as implant placement, a careful pre-operative observation is required. Cross-sectional imaging may be advocated to determine canal morphology and dimensions and to assess anterior bone width for potential implant placement buccally to the canal.

The progressive tapered shaft design of the ProTaper instrument was less influenced by the mid-root curvature than the constant tapered design of the K3 instrument thereby providing a good centred apical preparation. However, ProTaper instruments tended to transport towards the furcation in the coronal region.

This methodology is a new and objective way for quantitative evaluation of root canal instrumentation using microcomputer tomography and dedicated software.

The accuracy of surgical drilling guides was assessed for placement of zygoma implants. Six zygoma fixtures of length 45 mm (Nobel Biocare, Göteborg, Sweden) were placed in three formalin-fixed human cadavers using surgical drilling guides. The fabrication of these custom-made drilling guides was based on three-dimensional computerized tomography (3D-CT) data for the maxillary-zygomatic complex. The installation of the implants was simulated preoperatively using an adopted 3D-CT planning system. In addition, anatomical measurements of the zygomatic bone were performed on the 3D images. The preoperative CT images were then matched with postoperative ones in order to assess the deviation between the planned and installed implants. The angle between the planned and actually placed implants was < 3 degrees in four out of six cases. The largest deviation found at the exit point of one of the six implants was 2.7 mm. The present study showed that the use of surgical drilling guides should be encouraged for zygoma implant placement because of the lengths of the implants involved and the anatomical intricacies of the region.