Orthodontics in the Digital Age: More Than Just Teeth Straightening

This article highlights some of these technological advancements as they relate to orthodontics and provides a brief overview of the different modalities available to clinicians to treat patients' malocclusions.

It was Dr. Edward Angle, considered the "father of modern orthodontics," who suggested that the first molars were the key to a normal occlusion and that the maxillary first molar's mesiobuccal cusp should occlude with the buccal groove of the mandibular first molar. By placing the emphasis solely on tooth positioning, he created an easy-to-understand treatment philosophy that centered on placement of teeth in a proper location in order to articulate ideally with their dental counterpart. His four classifications of class I normal, class I, class II, and class III malocclusions have been the foundation of orthodontics for more than 100 years. The reality of orthodontics is that due to tooth size discrepancies, skeletal jaw sizes, and other aberrations, the ideal class I occlusion, unfortunately, is not always possible.

To become a board-certified orthodontist by the American Board of Orthodontics, a clinician must possess the clinical capacity to create an ideal occlusion and accurately analyze casts in order to evaluate the alignments, rotations, marginal ridges, buccolingual inclination, overjet, occlusal relationship, and, finally, root angulation of each tooth in the dentition. Unfortunately, a disparity exists between such academic objectives and clinicians' day-to-day reality. A main goal of any clinician is patient satisfaction, which is heavily dependent on how the smile fits the patient's face. This disconnect, or failing to place enough emphasis on the face, is of paramount importance. Today, most clinicians' treatment objectives are more facially driven as they seek to ensure that no treatment rendered negatively impacts their patient's facial profile or esthetics.

When evaluating traditional orthodontic mechanics, clinicians need to consider four key elements: bracket selection, bracket positioning, arch-wire selection, and force levels.¹ The treatment modalities available today are based on varying each of these elements in order to provide patients with different options to reach the same goal: a healthy, functional, and beautiful smile. Before elaborating on specific appliances, a brief overview of how technology has shaped the orthodontic profession is in order.

At the forefront of the advancement of orthodontics has been the utilization of intraoral scanners. Compared to traditional alginate impressions, they provide patients with a more favorable technique for capturing their dentition and occlusion. Intraoral scanners allow practices to avoid cumbersome laboratory procedures and free up significant space needed to store all of the casts. Most importantly, digital impressions provide clinicians more information than stone models. Digital software allows practitioners to make the same measurements while also providing the ability to overlap the STL files with the DICOM files from cone-beam computed tomography (CBCT) scans and even with digital facial scans.

The increased use of CBCTs has allowed orthodontic professionals to expand their scope of practice to better diagnose and treat issues ranging from periodontal limitations to airway concerns. A growing body of literature is available to help clinicians transition from 2D cephalometric standards to a new 3D approach to understand growth and development.^2,3

Intraoral scanners and available dental software have allowed clinicians and companies to provide highly customized treatment options. An overview of available treatments are discussed in the following sections, highlighting pros and cons from clinician and patient points of view. Whether a patient decides to utilize traditional braces, lingual braces, or clear aligner therapy, clinicians should be able to navigate the decision regarding which modality might be best to accomplish the patient's desired goals and articulate the risks and benefits to their patient.

With traditional braces, the two primary options are twin brackets or self-ligating brackets. Within each of these options a patient can decide whether they prefer metallic or ceramic brackets. Brackets can be placed in a direct method, which relies on the clinician's ability to properly position each individual bracket, or an indirect method, which employs prefabricated trays, with the brackets located inside of them according to their ideal position. Advantages of traditional twin brackets is cost and the practicality of removing or placing elastomeric or steel ligature ties. The friction in self-ligating brackets is reported to be less than traditional brackets, and in both situations it is higher when using a ceramic option. Arch-wire selection varies tremendously depending on the clinician's preference, but the three most common are nickel-titanium, beta-titanium, and stainless steel.

Lingual braces are an excellent option for patients who desire the esthetics of "invisible" orthodontics and do not want the responsibility of removing their aligners when they eat or drink or replacing aligners on a weekly basis. Lingual braces were introduced in the 1970s, and their popularity declined due to substandard outcomes and technical difficulties of applying. With advances in technology lingual braces have seen a re-emergence in their utilization. Most require an intraoral scan, and in some cases the CBCT can be merged to help with better control of root position. In a recent survey of practicing orthodontists in the United States, it was reported the largest challenges with lingual orthodontics pertained to their longer chairtime, technical difficulties, cost, and patient discomfort.⁴ Different products in the lingual orthodontic space include appliances that move teeth individually or use a "smart-wire" with non-sliding mechanics. Based on the aforementioned survey, most clinicians claimed to treat less than 10% of their total cases with lingual braces.

Clear aligner therapy (CAT) has been a highly significant treatment modality in the dental profession in recent years. There are essentially three categories for aligners. Professional aligner companies, such as Align Technology, Straumann, and Henry Schein Dental, just to name a few, lead the way in supplying clear aligners in the CAT market. Secondly, an increased availability of 3D printers has enabled dentists to leverage dental software to design, fabricate, and print their own clear aligners to treat patients. Fortunately, the third category, "do-it-yourself" orthodontics, is rapidly losing favor as patients realize that the lack of professional supervision can lead to lackluster results and increased issues that require professional attention.⁵

Patients who want the increased esthetics and flexibility of being able to remove their orthodontic appliance tend to favor CAT. An advantage of CAT is that a patient is easily able to perform optimum oral hygiene. A major caveat here is ensuring patients understand the importance of removing their aligner while eating or drinking (other than pure water). Several cases have been reported with decalcifying lesions, carious lesions, and other health and esthetic concerns when patients leave their aligners in during eating or drinking.⁶

In the adult population, especially those predisposed with periodontal disease, surgically facilitated orthodontic therapy can provide patients orthodontic treatment that they had previously been denied from having. The treatment itself is highly technique sensitive and involves a full-thickness flap elevation, cortication of the bone with a surgical handpiece or preferably a piezotome, and then osseous grafting. A membrane or platelet-rich fibrin can also be utilized for improved handling properties of the bone graft. The use of this option may allow the avoidance of extractions in certain borderline-extraction patients.

Several other, less surgically oriented options are also available to accelerate orthodontics. Tooth vibration appliances and micro-perforations are being used with various levels of success to accelerate tooth movement. The literature, however, remains inconclusive regarding the full efficacy of such methods to predictably increase tooth movements.

As dental technology continues to progress, clinicians should be able to leverage it to provide even more customized and efficient care to patients. Shorter duration of treatment, increased comfort during treatment, attractive esthetic outcomes, and lasting retention are among the ideals clinicians strive for to accommodate their patients, and technology helps achieve these ideals. Furthermore, the ability to provide ultra-low dose radiation during a CBCT scan can help clinicians detect suspected airway obstructions, and this information can then be relayed to medical colleagues for further investigation and diagnosis.

Orthodontics is no longer limited to bending wires and straightening teeth. Utilizing high-tech tools such as intraoral scanners, CBCTs, and 3D printers, combined with novel research about the importance of maintaining adequate airways, aligning teeth to maintain periodontal health, and preserving facial structure, is shaping the future of orthodontics.

The author has financial affiliations with Align Technology, Straumann Group, and Henry Schein Dental.

Daniel Berant, DMD
Double board-certified specialist in Periodontics and Implant Surgery and Orthodontics and Dentofacial Orthopedics; Private Practice, Manhattan, New York