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JADA Specialty Scan - Orthodontics
Orthodontics - A Quarterly Newsletter on Dental SpecialtiesJADA Specialty Scan

Treatment options for replacing missing maxillary lateral incisors

Editor’s note: You’ve just discovered that your 8-year-old daughter is missing both of her permanent maxillary lateral incisors. Not a problem. As you know, you can give her some beautiful implants when she is older and all will be fine. Then again, maybe your daughter doesn’t need implants because the orthodontists you work with have treated patients by bringing the canines forward and “restoring” them along with the first premolars, and the smiles look great. What are you going to do, and, for that matter, what are the considerations for similar patients in your practice?

While management of missing maxillary anterior teeth revolves around a solid diagnosis, treatment planning, and clinical excellence in achieving orthodontic and restorative goals, as clinicians we need to be aware of the multiple options available. The patient is best served by considering them all, as well as by seeking the input of the patient, the parents, or both. Our professional guidance must be based on a long-term perspective of good periodontal and functional health, along with esthetics. This series of articles presents current thoughts on replacing missing maxillary lateral incisors and documents continuing improvements in our treatment options. Much to consider for your 8-year-old daughter—and your patients.


Consulting Editor: Lee W. Graber, DDS, MS, MS, PhD
Diplomate, American Board of Orthodontics


Long-term periodontal status of patients undergoing orthodontic space closure for congenitally missing maxillary lateral incisors

Treatment for congenitally missing maxillary lateral incisors needs to meet patients’ esthetic concerns and functional requirements, as well as maintain the health of periodontal tissues. This study on canine substitution, published in the March 2016 issue of American Journal of Orthodontics and Dentofacial Orthopedics, investigated associations between orthodontic space closure and periodontal tissue deterioration over a 10-year period, as well as any signs or symptoms of temporomandibular disorder (TMD).

The authors conducted a retrospective cohort study consisting of 2 groups of orthodontic patients treated by the same orthodontist. The agenesis group (AG) had 26 patients with at least 1 missing maxillary lateral incisor, and the control group (CG) had 32 patients with no congenitally missing maxillary lateral incisors. All patients in both groups had completed orthodontic treatment a minimum of 60 months before follow-up.

Patients in the AG group had undergone orthodontic space closure with first premolar intrusion and canine extrusion to replace the missing maxillary lateral incisors. Space closure involving premolar intrusion and canine extrusion can remodel the gingival margins so that an “optimal, natural-looking result can be achieved,” the authors wrote. However, the treatment theoretically might create later periodontal problems or lead to improper functional occlusion, possibly predisposing the patient to TMD.

To assess the periodontal health of all maxillary and mandibular teeth in the AG, one examiner, who was not involved in treatment, conducted all of the clinical examinations and interviews. The periodontal examination included evaluation of probing pocket depth, bleeding on probing, plaque accumulation, gingival recession, and tooth mobility at 6 locations on each tooth. The examiner also compared the periodontal status of the maxillary teeth that were moved mesially in the AG with homologous data in the CG.

The study findings show that orthodontic space closure treatment with fixed appliances and first premolar intrusion and canine extrusion did not “increase the risk of periodontal tissue destruction and attachment loss in the long term.” Specifically, in the AG group, only 0.5% of sites probed had a pocket depth of more than 4 millimeters, and 2.4% had a pocket depth of 4 mm. In comparison, 0.7% of sites probed in the CG had a depth of more than 4 mm, and 3.9% of sites had a depth of 4 mm. The authors point out that “97.1% of the probing pocket depths around the intruded premolars and extruded canines were within normal limits,” and these results were almost identical to those around intact canines and lateral incisors in the CG patients. In addition, the findings showed no statistically significant differences between the 2 groups regarding increased tooth mobility.

To assess TMD symptoms, such as pain, noises, locking, and parafunction, the authors administered a questionnaire to both groups. Most patients (92.3%) in the AG group had a group function occlusion in lateral excursions. A canine-raised occlusion was observed in 7.7% of patients in the AG group compared with about 32% of patients in the CG. The authors found a minimal (> 1 mm) centric occlusion–centric relation discrepancy in the AG group, whereas no discrepancy was found in patients in the CG. TMD signs and symptoms were distributed equally in the groups.

The authors conclude that the periodontal status of patients in the AG was comparable to that of those in the CG who underwent similar orthodontic treatment. Although the periodontal and functional findings in patients treated with canine substitution were convincing, they recommended that prospective, randomized clinical trials with a larger sample size would be ideal.

Read the original article.

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Transplant versus implant in a patient with congenitally missing maxillary lateral incisors

Treatment options for congenitally missing maxillary lateral incisors most often include canine substitution—usually requiring orthodontic space closure—placement of dental implants, and tooth-supported restorations. In this case report, published in the May 2016 issue of American Journal of Orthodontics and Dentofacial Orthopedics, the authors describe a 19-year-old woman who sought orthodontic treatment owing to dissatisfaction with the esthetics of her smile. The report brings up another treatment planning approach and offers outcome comparisons.

The clinical examination and analysis of study models showed spacing in the anterior maxilla, a Class I molar relationship on the right side, a Class II molar relationship on the left side, and a 3-millimeter maxillary midline shift to the right side. A panoramic radiograph confirmed agenesis of both maxillary lateral incisors and revealed impacted third molars.

The patient refused the option of orthodontic space closure and canine substitution. Radiographic evidence of a small, unerupted maxillary left third molar led to the decision to transplant the tooth to the site of the missing right lateral incisor. A narrow-platform implant would replace the second missing lateral incisor. To correct the occlusion and create enough space for the implant and transplanted tooth, the clinician extracted the second premolars.

Eighteen months after orthodontic treatment began, adequate space had been created for the transplant tooth and implant. Surgery was performed to gently expose the unerupted, single-rooted third molar and transfer it to the prepared recipient site, with the tooth crown above the gingival level. The clinician stabilized the orthodontic wire for 2 weeks until the sutures were removed. Two months later, a dental implant was placed on the contralateral side. The healing abutment was placed 6 months later, and 2 months after that, a porcelain crown was cemented on the implant and a temporary composite buildup was placed on the transplanted tooth (5 years later, a zirconium crown replaced the composite buildup). After treatment, the patient was examined every year for 9 years.

So how did these 2 solutions for missing lateral incisors fare in the same patient? No clinical symptoms of inflammation (bleeding, redness, deep pockets) were observed at any location at the 9-year follow-up examination. The transplanted third molar had normal mobility and a low percussion sound, indicating absence of ankylosis. In addition, the periodontal status of the transplanted third molar and the implant did not differ significantly from that of the natural incisors, except for higher probing depths for the implant.

Bacterial DNA testing from the gingival crevicular fluid showed a 10-times higher total bacterial count at the implant site than at the transplant or control sites; however, the counts were not high enough to warrant antibiotic treatment for periodontitis. About 2 years after treatment, a bluish color became visible through the soft tissues above the dental implant crown.

Although both treatments were effective over the long term, the periodontal tissues around the implant exhibited progressive signs of recession, while the tissues around the transplanted tooth did not differ from those around the natural teeth. The authors concluded that, when replacing missing teeth in the anterior maxilla, natural tooth substitutions (transplants or orthodontic substitutions) are recommended whenever possible.

Read the original article.


Laypeople’s perceptions of treatment options for missing maxillary lateral incisors

Agenesis of maxillary lateral incisors can have an adverse effect on the dental appearance of adolescents. The most commonly elected treatment options include orthodontic space closure and repositioning of the canine tooth (OSC) and space opening and prosthetic replacement (PR). To investigate laypeople’s perceptions of teeth treated with OSC or PR, the authors administered a web-based survey to students and staff at the University of Sheffield in Sheffield, South Yorkshire, United Kingdom. The study was published online April 18, 2016, in Journal of Orthodontics.

The authors e-mailed orthodontists working in the region of the dental teaching hospital and asked them to send posttreatment intraoral images of any patients with bilateral, developmentally absent, maxillary lateral incisors who had undergone OSC or PR. They received 41 images, of which 21 were acceptable. Five orthodontists and 5 restorative dentists were shown the printed images and asked to rank them in order of attractiveness. The 5 highest-ranking OSC images and 5 highest-ranking PR images were included in the online survey.

In the first part of the survey, participants—who were recruited via e-mail—were asked to assess each of the 10 randomly presented images using a scale (0 = “very unattractive,” 4 = “very attractive”). In the second part of the survey, participants viewed paired images that were matched according to the specialists’ rankings (that is, the highest-ranked OSC image was paired with the highest-ranked PR image, the second-highest-ranked OSC image was paired with the second-highest-ranked PR image, and so forth). The researchers randomly placed the OSC and PR images on the right or left side. For each pair, respondents were asked to pick the image they preferred.

The investigators received a total of 959 completed responses pertaining to the attractiveness of the 10 images. Participants judged 45.7% of the OSC images to be attractive or very attractive and 40.5% of the PR images to be attractive or very attractive. Respondents found 20.1% of the OSC images to be unattractive or very unattractive, while they found 29.3% of the PR images to be unattractive or very unattractive. The mean attractiveness score for the OSC images was 3.34 and that for the PR images was 3.14 (P < .001).

For the paired images, 59.6% of responses indicated a preference for the OSC image. Female participants expressed a slightly higher preference (61.4%) for the OSC image than did male participants (58.1%).

The study results reveal that laypeople found the OSC images to be slightly more attractive than the PR images. In addition, when shown a matched pair of images, they expressed a slight preference for the OSC image.

The authors point out that cost and duration of treatment are other factors to consider when treating a patient with missing maxillary lateral incisors. OSC is likely to cost considerably less than PR, both during treatment and in long-term maintenance. Also, OSC enables treatment to be performed during early-to-mid adolescence, whereas orthodontic treatment with PR “tends to be delayed until mid-adolescence to allow for a short transition to placement of bridges or implants,” the authors wrote. Finally, they caution dentists about advising patients with missing maxillary lateral incisors that space opening and PR will achieve a better esthetic result than OSC.

Read the original article.


Dental professionals’ and laypeople’s esthetic perceptions of treatment for congenitally missing maxillary lateral incisors

Agenesis of 1 or both maxillary lateral incisors occurs in about 2% of the population. When weighing treatment options, dentists must consider functionality, esthetics, and periodontally acceptable results. The authors investigated the esthetic preferences of orthodontists, general dentists, and laypeople regarding treatment of congenitally missing maxillary lateral incisors. This study was published in the September 2016 issue of American Journal of Orthodontics and Dentofacial Orthopedics.

Study participants included 87 orthodontists, 100 general dentists, and 100 laypeople. The orthodontists and general dentists were attendees at national dental and orthodontic meetings, and the laypeople were patients and relatives of the patients in the investigators’ dental offices.

Participants were shown 9 intraoral frontal photos, 3 of which represented space closure with canine substitution, 3 represented space opening and replacement with implant-supported crowns, and 3 were of orthodontically treated dentition with no missing teeth in central occlusion (controls). A panel of 4 orthodontists and 2 general dentists had judged these photos—selected from the authors’ archives—to be the best treatment outcomes. All photographs were taken 12 to 24 months after completion of orthodontic treatment and final restorative procedures.

To measure the esthetic appeal of the treatment outcomes, the investigators distributed a questionnaire with a fixed set of 7 bipolar adjective pairs for each photograph. The 7 randomly arranged pairs were good-bad, satisfactory-unsatisfactory, usual-unusual, nice-awful, attractive-unattractive, beautiful-ugly, and pleasant-unpleasant, with a ranking from 1 (best) to 5 (worst) for each pair. Respondents circled the number that best expressed their feelings toward the photograph.

Orthodontists rated the dentitions with no missing teeth as significantly more pleasing than those with implant-supported crowns or space closure with canine substitution (P < .0001). Only a minor difference was found between their ratings of implant-supported crowns and those of space closure with canine substitution.

General dentists also preferred the dentitions with no missing teeth over those with implant-supported crowns or space closure with canine substitution (P < .05). Unlike orthodontists, however, they rated dentitions with space closure and canine substitution higher than those with implant-supported crowns.

Laypeople preferred space closure and canine substitution to implant-supported crowns (P < .001). They even favored dentitions with space closure over those with no missing teeth, although the difference was not statistically significant. When asked why they preferred space closure to no missing teeth, laypeople commonly said, “the 4 front teeth appear more equal” and the “mouth is less toothy.”

A second objective of this study was to compare these findings with those of a similar study conducted by Armbruster and colleagues in 2005 to determine if dental professionals’ and laypeople’s judgments had changed over time. The authors found the “greatest and statistically highly significant improvements” for the esthetic ratings of implant-supported crowns in all 3 respondent groups (P < .0001). This reflects improvements in materials as well as techniques in restorative dentistry.

As these study findings show, esthetic perceptions of dental professionals and laypeople can differ. The authors conclude that in the “absence of randomized controlled trials about long-term esthetic and functional stability” associated with standard treatments for congenitally missing maxillary lateral incisors, “dental professionals should refrain from imposing their esthetic preferences on patients.”

Read the original article.


Save time with the NEW JADA+ Clinical Scans

The Journal of the American Dental Association (JADA) is making it easier for members to access the latest scientific studies.

The new JADA+ Clinical Scans provide a brief overview of selected articles and offer a scientific- and evidence-based assessment of the published research, providing critical information that helps dental professionals integrate their patients’ needs and preferences into treatment decisions.

Covering a range of topics from periodontal treatment to sleep quality, the clinical scans are a quick read at about 500 words each.

“As clinicians, academicians, and researchers, we are deluged with information from a multitude of sources—some more trustworthy than others,” said Dr. Michael Glick, JADA’s editor. “That’s why we created JADA+ Clinical Scans, which are an essential, complementary resource in addition to the training and experience of oral health professionals.”

ADA members can access more than 40 JADA+ Clinical Scans at New clinical scans are added frequently, so check back often.

AAO consumer alert warns against DIY orthodontic treatment

The American Association of Orthodontists (AAO) actively educates the public about the dangers of do-it-yourself orthodontic treatment. Thanks to social media, people are led to believe they can move their own teeth and are likely unaware of the potential for periodontal disease and avulsed teeth.

Good Morning America aired an interview March 10 with AAO’s president, Dr. DeWayne McCamish, who cautioned viewers that shortcuts could be disastrous. Share this consumer alert and short video regarding “DIY” orthodontic treatment available on the AAO’s public website.


ADA brochure helps straighten treatment misconceptions

Whether your patients are children, adults or both, the ADA brochure, “Orthodontic Treatment: For a Healthy, Straight Smile,” is the perfect tool to explain braces, aligners, and surgery. With misconceptions about the right patient age and the right way to care for your teeth after treatment, this brochure sets the record straight. Your patients will learn there is no right age, but it’s best to seek treatment early. They will also learn the do’s and don’ts of braces to help get the most from treatment. 

The “Orthodontic Treatment” brochure lets patients not only read about the benefits; it also includes before-and-after photos so patients can see the benefits of treatment. The 8-panel brochure is available in packs of 50 from the ADA Catalog. A sample can be viewed here. To order, call 1-800-947-4746 or go to Readers who use the code 17401E before April 18 can save 15 percent on all ADA Catalog products.

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These quarterly e-mailed newsletters deliver the latest information on dental specialties — endodontics, oral pathology, orthodontics, prosthodontics, periodontics, pediatric dentistry, radiology and select dental disciplines — cosmetic/esthetic and osseointegration — to the dental profession. Each issue provides news and the latest techniques used by practicing dentists and experts for each of these specialties and disciplines. JADA+ Scans e-Newsletters are emailed quarterly.


JADA+ Specialty Scans and JADA+ Scans

This is one in a series of quarterly newsletters updating dentists on selected specialties in dentistry. Information presented is aggregated and summarized from previously published materials, each item attributed to its publication of origin. This issue of JADA+ Specialty Scan focuses on orthodontics, the first in the series on this topic for 2017. Other Specialty Scan issues are devoted to endodontics, oral and maxillofacial radiology, oral pathology, pediatric dentistry, periodontics and prosthodontics. The ADA has engaged the specialty organizations in these areas as well as its own Science Institute and Division of Legal Affairs to assist with these newsletters. We welcome feedback on this and all Specialty Scan issues.

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