Contemporary Orthodontic Treatment Planning

In dentistry, the term “esthetics” generally refers to the appearance of the smile and anterior tooth display. The dental journals are replete with articles and case reports on smile reconstruction. Historically, the orthodontic literature has portrayed esthetics as somewhat limited in scope to the profile, but more recently, articles are rapidly incorporating the elements of smile design into their treatment strategies. Rather than thinking of orthodontic treatment as merely “straightening teeth,” practitioners should think of it as more of a long-term commitment to the development of three major areas: occlusion, smile esthetics, and facial esthetics. Another important consideration in the thought process of the dental team should be that of the patient’s overall appearance, or how the smile and the face look in all dimensions. For too long, both dental treatment and orthodontic treatment have been thought of in “transactional” terms. In other words, each treatment is a transaction involving the performance of a service, such as teeth straightening, for an agreed upon fee. Contemporary orthodontic treatment should be seen as an opportunity to be “transformational,” which is an entirely different approach. This type of treatment presents an opportunity to literally shape, mold, and guide a growing patient, utilizing all of the members of the dentofacial team to achieve outstanding results. Planning orthodontics strictly based on cephalometric measurements has matured into a new era in which the “Soft Tissue Paradigm” dominates the orthodontic profession.^1-3 Rather than being determined by hard-tissue guidelines, such as dental relationships alone or cephalometric numbers derived primarily from static craniofacial measurements, a contemporary orthodontic treatment plan should anticipate long-term dental and facial changes and the dynamics of the smile in animation. Given the opportunity for guiding growth through interdisciplinary collaboration, we can now pursue a vision of both facial and smile design that can be strikingly positive in transforming a patient’s appearance.

Esthetic Classification: Macroesthetics, Miniesthetics, and Microesthetics

In 2001, Morley and Eubank offered concepts and guidelines on cosmetic dentistry and smile design in their paper “Macroesthetic Elements of Smile Design,” which was published in the Journal of the American Dental Association.⁴ Although they did make a reference to facial esthetics, the term “macroesthetic” was applied to the smile, and the term “microesthetics” was used to refer to tooth shape and proportion. Presently, these terms are used as part of a broader classification system:

Macroesthetics refers to the esthetics of the patient’s entire face as seen from various angles, not just the frontal view. Facial proportions create the broad framework around which more detailed characteristics are seen, but the combination of the individual elements of the face and how they frame the smile results in the relative attractiveness of an individual’s face.

Miniesthetics focuses on the display of the teeth as part of the smile, which means that it incorporates the position and contours of the soft tissues of the lower face and the gingival tissues around the teeth. Without a doubt, the smile has a significant impact on the assessment of overall facial appearance as well. The perception of a person’s appearance can be greatly enhanced by an esthetic smile.

Microesthetics concerns the shape and proportions of the teeth themselves with the primary focus on dental esthetics.

In orthodontics, practitioners can have an effect on any one or all three of these classifications, and the particular approach used will depend on whether the patient is an adolescent or an adult. Regardless of the desired result, all three of these classifications are interrelated. It is difficult to make a change that affects one of these categories without affecting the others. In other words, characteristics such as vertical facial proportions, profile, lip support, and placement of the maxillary incisors on smiling are all interdependent. Although different members of the dentofacial team may be called upon to contribute to an overall dental and facial design, remember that the basic role of the orthodontist is to plan and coordinate a treatment plan that satisfies any of these elements that the patient indicates as significant and wishes to improve.

Case 1: Appearance and The Lesson of Time

A 16-year-old female underwent full orthodontic treatment at age 12, resulting in both good occlusion and an esthetic smile (Figure 1). In order to accommodate the crowding, her arches were orthodontically expanded. As a result, both her maxillary and mandibular incisors were advanced labially, which created an acute nasolabial angle and de-emphasis of her chin due to the increased projection of the lips. (Figure 2). Perceptions of appearance and esthetics are a result of proportions and interrelationships. All dentists are aware of the controversies surrounding extractions in orthodontics. The clinician who treated this patient explained to her parents, “we never take out good teeth.” Although the original goals of arch alignment with class I occlusion were achieved, her parents were not particularly happy with the outcome. They debated whether to seek further treatment, but did not take action until the girl reported several hurtful incidents at school in which she was bullied and told directly that she was ugly. After presenting to the office for another opinion, the parents commented that they believed she looked better before the braces than she did after. To facilitate a discussion of possible treatment options, digital imaging was utilized to simulate the potential facial outcomes, just as dentists utilize it to simulate the goals of smile design.⁵ This process has many advantages. First, discussing the face on the computer screen rather than directing the commentary at the patient’s actual face is more considerate of the child’s emotions regarding self-image. Second, it is in a visual template that everyone can understand. And third, it facilitates a better discussion of the various treatment options by displaying their potential results.⁶ Orthodontic software utilizes algorithms derived from clinical research that relate the soft tissue response to hard tissue movements, usually on profile. For example, research demonstrates that if the incisors are moved 5 mm posteriorly, this may result in a 4 mm posterior movement of the lips. These types of relationships are entered into the computer’s database for soft tissue conversion to assist in rendering a reasonably accurate projection of the potential outcome.⁷ After consultation and reconsideration of treatment, the removal of four premolars was recommended to reduce the protrusion and achieve a better facial balance while maintaining proper occlusal relationships. Orthodontic retreatment was completed in 18 months, resulting in a more pleasing profile (Figure 3). Two years later, the patient was crowned “Miss Alabama.” It is important to point out that numerous studies clearly demonstrate that an aging characteristic common to both males and females is loss of the lip projection due to loss of soft tissue thickness and diminished skeletal and alveolar support.^8-14 So how can practitioners determine how much is too much retraction of the incisors and how much is just enough? The answer lies in the education and skill of the orthodontist who exercises prudent use of data along with the “art” of orthodontics. In this case, the protrusion was decreased, but not to the maximum retraction value. It was only decreased to a moderate degree because of the expected loss of lip support that naturally occurs as a result of the aging process. This anticipation of expected soft tissue change resulted in an ongoing excellent facial appearance, even 25 years after the completion of treatment (Figure 4).

Case 2: The Interaction of Macro-, Mini-, and Microesthetics

Knowledge of the maturational and aging characteristics of both the hard and soft tissues of the face has changed the approach to the treatment of growing children, and this case illustrates this change in strategy. A 7-year-old girl, who was brought into the office by her mother (the patient from case 1), presented with mild convexity to her profile, lip incompetence, and a mild class II malocclusion (Figure 5). The proposed treatment plan included correction of the malocclusion as well as long-term esthetic goals. During the initial discussions regarding treatment, it was revealed that her father was 6’9” tall—an important fact to keep in mind when anticipating a young patient's potential future growth. The lip changes and the amount of anticipated nasal growth, which occur during the prepubertal growth spurt, needed to be incorporated into the thinking process when designing her macroesthetic outcome.

By age 12, she had maintained a mildly dentally protrusive appearance while acquiring her transitional dentition. In a “miniesthetic” evaluation, it was observed that she still had lip incompetence and slightly inadequate incisor display on smile. In addition, her gingival margins were shorter on the laterals and canines than they were on the central incisors. Her profile was characterized by more nasal growth, and she still had a moderately acute nasolabial angle (often associated with dental protrusion) and chin deficiency (Figure 6). Although there was significant crowding in the mandibular arch, with the space remaining, it could certainly be accommodated. But without permanent tooth extraction, the retraction of the anterior teeth and subsequent reduction in protrusion was estimated to be minimal. Was she following the same path as her mother who ultimately required premolar extraction? The fact that the young girl had a similar build as her father and other indications that she was going to experience a lot of growth had to be taken into account when planning her orthodontic treatment. The goal of her orthodontic treatment was to improve the class II malocclusion, but at the same time maintain anterior incisor position for lip support. How this was discussed with her parents was fairly simple and did not require sophisticated technology or cephalometric analysis. After bringing the profile image up on the computer screen, everything below the upper lip was blocked from view (Figure 7). This demonstrated that the upper face and upper lip appeared to be quite normal in isolation and that her profile convexity was due to the moderate deficiency of the mandible and, in larger part, the chin. The same exercise can be performed from the frontal view to visualize her lip support in that dimension. At the conclusion of the conversation, a treatment plan was selected that involved nonextraction treatment in combination with headgear for class II correction through growth modification. In other words, the plan was to maintain the middle and upper soft-tissue position while improving the lower face. At the appropriate age (usually 15 years or older in females) when the soft tissue was appropriately mature, the patient would be reassessed for possible chin augmentation through an inferior border osteotomy.

The maxillary incisor is a major determinant in cosmetic dental treatment plans as well as orthodontic treatment plans. After orthodontic alignment, her “microesthetic” examination revealed that her maxillary central incisors were disproportionally larger than her maxillary lateral incisors and that this relationship was exacerbated by the fact that her maxillary lateral incisors were disproportionately smaller when compared with the surrounding dentition (Figure 8). It is entirely appropriate in orthodontics to reshape teeth and close any remaining space as a part of treatment.¹⁵ Therefore, in addition to some slight reshaping of her maxillary central incisors, her maxillary lateral incisors were lengthened using a combination of excisional gingivoplasty with a diode laser and composite bonding. Both of these procedures were performed by the orthodontist so that the sizes of the teeth could be visualized while the tooth movements were guided to achieve balanced maxillary incisor proportions (Figure 9).

After 20 months of orthodontic treatment and having attained the occlusal goals, the orthodontic appliances were removed and she was placed into retention. Her profile demonstrated even more nasal growth, resulting in the increased facial convexity that was expected (Figure 10). At age 15 (the appropriate time for 3rd molar removal), both the mother and the patient expressed their desire to have the chin augmentation via the inferior border osteotomy performed at the same time as the 3rd molar removal because the oral maxillofacial surgeon is required to perform both procedures. After surgery, the resulting profile was well-balanced with a good lip and chin relationship and a pleasing labiomental sulcus (Figure 11). Furthermore, her frontal facial proportions were excellent and the lip support was ideal (Figure 12). Choosing to perform an inferior border osteotomy instead of using an implant to augment the chin results in an increase in bone thickness on the anterior aspect of the lower incisors, which is an additional periodontal benefit.^16,17

Conclusion

As an orthodontist, what is the take-home message? Contemporary orthodontic treatment planning is based on the individual patient’s dental and facial characteristics rather than merely following a particular technique or philosophy. To put it simply, it is prudent to avoid the locked-in mindsets of “always” and “never.” Furthermore, treatment should always be tempered with a vision of the long-term benefit to the patient. In contemporary orthodontics, it has become mandatory that practitioners incorporate the principals of smile design into their treatment planning and pay close attention to the many elements of function and esthetics.

Disclosures

The author had no disclosures to report.

References

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About the Author

David Sarvar, DMD, MS
Private Practice
Birmingham, Alabama