CBCT as an interdisciplinary treatment-planning platform

Current Issue , Technology
Editor’s intro: Dr. George A. Mandelaris’ interdisciplinary approach to implant treatment planning includes CBCT imaging as an essential part of the process.

Dr. George A. Mandelaris discusses how CBCT imaging is essential for practicing in an interdisciplinary treatment-planning model

It’s well understood that cone beam computed tomography (CBCT) greatly aids in implant planning and treatment. The accuracy it affords is undeniable, especially when it comes to avoiding surprises during surgery and when considering the final restoration. However, CBCT allows implant surgeons to do even more for their patients. By adopting an interdisciplinary approach, doctors can reach across all disciplines to provide the full spectrum of care for their patients and address the core etiology of patient problems — and it all begins with a 3D scan.

CBCT is essential for practicing in an interdisciplinary treatment-planning model. The multiple fields of view that the most advanced systems, such as the CS 9600 CBCT system (Carestream Dental) feature, give doctors flexibility in determining what level of treatment planning is necessary for a patient. For example, a patient with a complex dentofacial disharmony skeletal malocclusion may be a good candidate for orthognathic surgery. In that case, a larger field of view — if not the largest — is necessary for planning; the CS 9600 offers 14 fields of view to cover all diagnostic needs.

CBCT also plays a role in risk assessment associated with orthodontic decompensation movements that would be needed to set the patient up for success and confidently judge the impact that such decompensation movements would have on the dentoalveolar structures. Is enough bone around the teeth present to accomplish the desired movements and not camouflage the patient? If not, do alternative applications of orthodontic therapy need to be considered, such as surgically facilitated orthodontic therapy (SFOT) in which the bone would be developed around the teeth to expand the orthodontic boundary conditions and optimize conditions for safe tooth movement? Figures 1 and 2 demonstrate a Class II dentofacial disharmony malocclusion patient who was managed by SFOT. Note the before and after dentoalveolar bone volumes around the teeth. Also note that with expansion orthodontia (accomplished by SFOT and improving the orthodontic boundary conditions), the change in airway dimension at C2.

Figures 3-5 demonstrate 3D images of a patient with a Class III dentofacial disharmony malocclusion who was also managed with SFOT. Figure 3 demonstrates the pre-op condition; Figure 4 demonstrates the 3D rendering of placing the teeth in the final correct position for facial esthetics and function but in the non-augmented pre-op bone anatomy. Note the lack of facial bone volume to accomplish the movements safely. The teeth are positioned outside the available bone envelope and cause iatrogenic risk to the periodontium, warranting such decompensation movements hazardous to the periodontium. If the bone volume is not augmented, the patient would settle for a compromised orthodontic result that would likely relapse. Figure 5 demonstrates the post-SFOT result of the patient with final tooth positions and the augmented bone volumes. Note that the teeth have not been compromised in the final outcome positions, and that the dentoalveolar bone volume has been augmented to allow such tooth movement to occur safely.

Figure 1: Sagittal CBCT slice pre-SFOT and Figure 2: Sagittal CBCT slice at 15 months post-SFOT

Figure 3: Pre-op, and Figure 4: Virtual final correct position for facial esthetics and function but in the non-augmented pre-op bone anatomy, and Figure 5: Post-SFOT result with final for facial esthetics and function tooth positions and the augmented but in the non-augmented pre-op bone volumes bone anatomy

Once a 3D scan is taken, it can be mapped to a diagnostic software that can provide a 3D orthodontic treatment simulation to show the patient how the teeth need to be moved and into what position. This eliminates guesswork and underscores informed consent at the highest level. Patients better understand the scope of their problem as well as all the opportunities for more optimal correction. The fact that the scope of treatment can be expanded also makes therapy more predictable and more stable. All team members benefit by having a patient more vested in their oral health care and better educated on what IDT therapy can provide for their long-term health.

Of course, orthognathic surgery and SFOT may seem like extreme examples. What about taking an interdisciplinary approach to planning and placing implants? Ultimately, implants are a restoratively driven process, and CBCT imaging aides with “top-down” planning. With today’s advanced technology, it’s not enough for the surgical specialist to simply place implants and assume the general dentist will figure out the restoration. Instead, CBCT allows the periodontist/oral surgeon to keep the final crown at the forefront of planning and executing implant surgery, while building an excellent rapport with the restorative doctor so there are no surprises. What’s more, this prosthetically driven approach toward implant planning is also moving in a context that must also be biologically driven. With all the emerging problems of peri-implant diseases, we’re learning more about who’s susceptible and how the treatments we perform at the chair influence how this disease develops. In many cases, problems can usually be traced back to the planning, and CBCT helps minimize that. Surgeons should not only be working closely with their referring doctors to achieve natural-looking and ideally placed prosthetics, but also be considering the long-term impact of implant placement and the inherent associated risks of patients developing peri-implant disease.

CBCT serves as a vehicle of high transparency; the surgeon can see what’s needed at every level so that every discipline can contribute to the overall outcome of the patient. This underscores the team approach, long-term outcome stability, and predictability associated with complex interdisciplinary treatment. Interdisciplinary treatment planning goes beyond just a pretty smile and a good bite; it’s about also developing a stable, healthy periodontium; a healthy, stable TM joint relationship; a good airway, and, in the end, sustainable oral health conditions for the lifetime of the patient.

CBCT’s role as part of the interdisciplinary approach to implant treatment planning is further explored in Drs. Bradley S. McAllister, V. Thomas Eshraghi, and Hector F. Rios’ article, “A review of the AAP’s best evidence consensus on the use of CBCT in the management of the patient requiring dental implants.” Find it here.