Perspectives

To Boldly Go Where No One Has Gone Before

It’s time to discuss the benefits and risks of three-dimensional analysis and answer the questions as to under whose authority should this new technology be assigned and how much time should be allotted to this novel method of data acquisition.

Stanley A. Alexander, D.M.D.

“He is intelligent, but inexperienced; his pattern indicates twodimensional thinking.” These were the words of Mr. Spock, reflecting on the actions of Khan Noonien Singh, a genetically engineered human from the movie “Star Trek II, The Wrath of Khan,” which premiered in 1982. As Spock alludes to this inexperienced pilot, we, too, are bound by the laws of gravity, and naively interpret our world in two dimensions, while the trained aviator, or in this case the captain of a starship in the 23rd century, is in full command of the X, Y and Z coordinates and well-versed in the true world of three or more dimensions, such as time.

As an orthodontics graduate student in the mid-1980s at Columbia University enrolled in a course titled “Functional Anatomy,” I was exposed to the novel concept of space-time [1-2] and its application to craniofacial growth. [3-6] The development of three-dimensional cephalometric analyses became popular with the use of new technology, cone beam computed tomography (CBCT), [7-12] which was novel among other clinical disciplines and now applied to orthodontic diagnosis and implant dentistry. Three-dimensional applications (3-D) eventually evolved for aligner therapy that has become a major component and quotidian activity in specialty and general practice.

When quoting the physicist Werner Heisenberg, “an expert is someone who knows some of the worst mistakes that can be made in his subject, and how to avoid them,” I begin to question where the training in 3-D analysis and interpretation is taught and by whom. Are not dentists and specialists experts in their respective disciplines? How much of the current dental curriculum in both the predoctoral and graduate levels is now channeled to this new field? I suspect a great deal of exposure is not allotted, as it requires a significant amount of time, for example, at the orthodontic graduate level to attain a level of proficiency that can then be transferred to patient therapy with growth prediction, aligner fabrication and 3-D printing.

With this new added component and the time constraints of a traditional four-year program in dentistry and additional years in specialty training, what other disciplines within the curriculum are being modified or eliminated as a result of this new technology? The answer is far more cryptic than might be expected, far more directional in whose domain claims the responsibility for its dissemination, and far more relevant to dental education. Should such skills be relegated to interdisciplinary coordination and not assigned to a single department?

Intraoral scanners are rapidly replacing impression techniques in general and specialty therapy, much to the benefit of the patient. This modern replacement, however, remains a static improvement over previous techniques, since it does not take into account or in fact need to, the subtle changes occurring over time in the craniofacial complex. In restorative dentistry, minor tooth movements with aligners, and overall orthodontic diagnosis and treatment, are we delegating this method of data acquisition and educational transfer to the dental manufacturers and, if so, are these the desultory reasons for “refinements” in aligner care due to the computer program’s inability to take into account the fourth dimension of growth in our developing teenage patients who opt for invisible care or in the remodeling of bone at the tooth-bearing interface?

When applied to the oral cavity, 3-D applications in dentistry should always be complementary: to describe the anatomy at a stated time in all three dimensions; to assure growth and remodeling changes are incorporated into the program based upon established norms (yet already incorporating a weakness within the analysis, as it is not specific, but applies to population groups); and to assist in the fabrication of an appliance or prosthesis for patient care.

Have we acquired the tools for three-dimensional thinking? Ultimately, it will be dependent upon the goals of each institution to instill this information in its future graduates. General intelligence does not replace acquired experience but augments it. The time is now for the university to begin this transition into the world of the third and fourth dimensions of patient care.

Queries about this article can be sent to Dr. Alexander at stanalexander427@ gmail.com.

Dr. Alexander

Stanley Alexander, D.M.D., is distinguished teaching professor emeritus, Stony Brook University, Stony Brook, NY.

REFERENCES

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2. Vilmann H, Moss ML, Skalak R, Vilmann O. Space time presentations of the shell of the bivalve mollusk Cardium edule. Am J Orthod 1981;80(4):417-428.

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Am J Orthod Dentofacial Orthop 1997;112(1):8-11 7. Mah JK, Huang JC, Choo HR. Practical applications of cone-beam computed tomography in orthodontics. J Am Dent Assoc 2010;141(Oct, Suppl 3):7S-13S.

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10. Askari M, Williams R, Romberg E, Stone M, Alexander SA. CBCT assessment of dental and skeletal changes using the Damon versus conventional (MBT) system. Dentistry 2015;5(10):1-10.

11. Naeem OA, Bencharit S, Yang IH, Stillianoudakis SC, Carrico C, Tufekci E. Comparison of 3-dimensional printing technologies on the precision, trueness, and accuracy of printed retainers. Am. J. Orthod Dentofacial Orthop 2022;161(4):582-591.

12. Sangalli KL, Dutra-Horstmann KL, Correr GM, Topolski F, Flores-Mir C, Langravere MO, Moro A. Three-dimensional skeletal and dentoalveolar sagittal and vertical changes associated with cantilever Herbst appliance in prepubertal patients with Class II malocclusions. Am J Othod Dentofacial Orthop 2022;161(5); 638-651.