I begin my races visualizing the finish line and what I need to get there. With marathons, I usually need a cab. With implants, the finish line is the final restoration. You will make your referring GPs’ Christmas, Hanukkah, Tet, Eid, Kwanzaa, and Groundhog Day gift lists by placing implants within the quadrants’ curve of spee and minimizing the need for custom abutments or cantilever crowns. Some CBCT software packages (including our Anatomage) enable you to virtually place the final crown and view the abutment as you’re determining implant placement. By maneuvering the final crown into position between the neighboring teeth, implant planning with cone beam moves from an educated guess to a very precise determination.
What should be done when there are no neighboring teeth to determine final crown placement? In other words, what is your first implant planning step when the finish line is extremely murky? (If you answered “refer it out,” you’re wise. Wisdom and honesty and humility are all closely related.)
In this case a young man in his 20s suffered trauma that knocked out 7-10 and left insufficient bone for implants on 7 and 10. The GP and oral surgeon decided to place implants on 8 and 9 and, depending on insurance and the patient’s decision, revisit the laterals later.
First we virtually placed implants on 8 and 9. The software shows their emergence profile angles (see the long thin white lines), and to confirm we were in the ballpark we placed implants on 6 and 11. After the angle was correct (near parallel) we deleted the unneeded 6 and 11 “reference” implants. This mirrored the rotation and a slight facial tilt in line with the rest of the anteriors, even though the neighboring teeth (7 and 10) are absent.
Next we placed restorations on the virtual 8 and 9 implants. We measured the total edentulous area to determine the approximate width of each central. Although these will not be the final restorations, we wanted a close approximation because we wanted to place the implants as close to dead-center as possible. The implant abutments are shown in orange outlines and clearly show if they need to be custom (not in this case). We were also able to use the incisal foramen as an approximate midline. (This shouldn’t be standard practice as the incisal canal doesn’t necessarily follow the true midline; we just got lucky in this case.)
With this information Reveal Diagnostics ordered a surgical guide, which arrived at 8am the following day at the oral surgeon’s office (again, thanks Anatomage). If the patient elects to have implants placed on 7 and 10 (presumably after some bone augmentation) and we take another cone beam 3d x-ray scan, we’ll post the after CBCT pictures!
