The ease with which we can visualize simulated orthodontic treatment in three-dimensional images and the fact that we can so easily make changes to a simulation is an example. The ability of all parties to immediately share, store and discuss cases can improve care delivery, but it can also lead to complacency. Patients do not always respond in the ways we see in simulations, and our treatment planning should never be reduced to thinking, “the simulation looks good, so we can print aligners and start treatment.” Commercial inter-ests may promote the easy, fast and visible results obtained by their products, but multiple obstacles can stop us from achieving the ideal simulated results. Learning from the examination of relapse, for example, is critical. Relapse is a reliable indicator of a disturbed functional matrix. We must respond to relapse in our patients’ dental history by deter-mining the abnormal forces in the myofunctional, orofacial environ-ment and planning for their resolu-tion and/or modified retention. Observing abnormally slow orthodontic movement of the teeth during treatment offers another, similar clue. Again, it is usually the case that the functional matrix is imbalanced. Aligners have been found to reduce open bites with greater success than braces. It’s likely that abnormal, negative forces from a tongue thrust are reduced while an aligner is being worn over occlusal and incisal edges, so movement of the teeth is more predictable. Let’s consider another wearing-compliance possibility, which not only would change the functional matrix but also alter the simulated results we reviewed before ordering aligners. Perhaps an adult patient is not able to wear aligners because of an unrevealed thumb-sucking habit. The patient might have to remove one or both aligners to begin going to sleep and occasionally forget to put them back in, resulting in zero or reduced nighttime wear. Indeed, such a case has been observed; fortu-nately, the adult patient, sensing her care provider’s bewilderment that she was not progressing normally with full braces, asked if her thumb sucking could be a problem. Other concerns that might be less obvious would be a new or worsened persistent tongue-between-teeth (TBT) swallow of saliva or a new or worsened vertical rest position and mouth breathing. In either case, the “new” or “wors-ened” conditions would introduce possible changes to the functional matrix. Consider, for example, the possible effect of months of wearing a rapid palatal expander with the screw dramatically reducing tongue space. It’s virtually certain the patient would adopt a more abnor-mal swallow and lowered resting tongue posture. Perhaps in the future, expansion using only aligners (avoiding RPEs) will be considered the most desir-able treatment to avoid worsening of the resting tongue position and swallow and negatively impacting the functional matrix. It’s not hard to imagine, with improvements in aligner materials, attachments, wearing protocols and other changes, that radiographic studies may someday demonstrate compa-rable skeletal expansion effects among aligners and all other appli-ances available. Such a change could simplify design and refine redesign, creating the opportunity to deliver two or even three phases of expansion, in contrast to the more difficult placement of tradi-tional RPE designs and less patient friendly miniscrew-assisted rapid palatal expansion intervention. We now understand that facial-skeletal growth and change is not solely determined by genetics, but also influenced by long-term musculoskeletal forces. Treatment of malocclusion cannot be simpli-fied to the mechanics that are most efficient to tip, rotate, intrude or otherwise move a tooth. Treatment of the functional matrix with an initial assessment of how abnormal the condition is and what improvement is reasonable to expect is necessary. Many early dental school educa-tions narrowed practitioners’ focus to restorative care. The loss of teeth was more prevalent before fluorides and routinely available dental care, and dental education responded to that societal need. The teaching of restorative care is technique sensi-tive, with little to no room for a teaching style that encourages trying an approach, re-evaluating to see how the patient responds and refining the treatment plan. Our societal model for restorative dental care has deep roots in a “fix it or pull it” mentality. The Matrix Focus in Practice Let’s review a hypothetical func-tional matrix-based case. Imagine a patient suffering from a deficient airway and the following adapta-tions to mouth breathing. The indi-vidual presents with the abnormal postural rest position of a forward protrusion chin positioning, uncon-sciously developed to allow the patient to live with difficulty breath-ing easily through the nose. The chin is protruded by tilting the crown of the head backward (as if looking above) to effectively shift their mandible forward relative to the upper cervical vertebrae (open-ing the upper airway). Adopting a 16 Winter 2025 JAOS
Journal of the American Orthodontic Society Winter 2025: Page 16
