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

Assessing gingival recession after orthodontic treatment

Is orthodontic treatment a predisposing factor in gingival recession? In this retrospective study, researchers evaluated the long-term prevalence of gingival recession after orthodontic movement of the mandibular incisors, maxillary premolars, and maxillary first molars. The study was published in the May issue of American Journal of Orthodontics and Dentofacial Orthopedics.

The investigators evaluated 327 patients from 2 private orthodontic practices in Texas. Inclusion criteria were the availability of dental records at the start of treatment (T1), the end of treatment (T2), and long-term follow-up (T3) (at least 2 years after appliances were removed). The final sample consisted of 205 patients, 162 of whom (79%) were female, the authors wrote. Patients’ mean (standard deviation [SD]) age was 13.9 (5.9) years at T1, 16.5 (6.0) years at T2, and 32.3 (8.5) years at T3. Treatment lasted an average (SD) of 2.5 (1.1) years.

The investigators examined the frontal and buccal intraoral photographs taken at T2 and T3 and the cephalometric radiographs obtained at T1 and T2. In addition, 5 standardized photographs of the dental models were taken at T1, T2, and T3, the authors wrote. Information pertaining to ethnicity, Angle classification, expansion type (rapid palatal “orthopedic” expansion or archwire dental expansion), tooth extractions, retention type and duration, and dates were obtained from the patients’ dental records.

Whenever possible, the researchers used intraoral photographs to measure gingival recession. At T2 and T3, they measured recession bilaterally on the mandibular incisors, the maxillary premolars, and the maxillary first molars. If the cementoenamel junction (CEJ) was not visible, they recorded a score of 0. The authors defined mandibular incisor recession as the distance between the gingival margin and the CEJ on the midfacial surface. Because of measurement variability, recession on the facial aspect of the maxillary first molars was defined as the maximum distance from the gingival margin to the CEJ anywhere on the maxillary first molars, the authors wrote.

All scanned images were imported into cephalometric software (Viewbox, Version 4, Dhal Software). When intraoral photographs were unavailable or their quality was poor (about 20% of cases), the researchers used the Viewbox software to measure recession on the scanned dental models.

To measure mandibular incisor inclination, the authors used the T1 and T2 cephalometric radiographs (n = 199), which they traced using Dolphin Imaging software. The researchers calculated mandibular incisor angulation from customary orthodontic cephalometric measures.

The researchers used occlusal photographs of the T1 and T2 models to evaluate arch expansion. They measured the maxillary intermolar and interpremolar distances from the most lingual point on the lingual gingival margin to the same position on the corresponding contralateral tooth.

At T2, only 18.3% of patients exhibited gingival recession on at least 1 tooth, and 5.8% of teeth examined exhibited recession after treatment, the authors reported. Between T2 and T3, significant (P < .001) recession occurred, with the highest prevalence in maxillary first premolars, the authors wrote. However, although almost 60% of maxillary first premolars demonstrated recession, only 7.7% had recession of more than 1.0 millimeter. Almost 53% of mandibular central incisors exhibited recession at T3, but it was greater than 1 mm in only 10.3% of teeth. Among mandibular lateral incisors, maxillary second premolars, and maxillary first molars, 32% to 37% exhibited recession at T3. Overall, 55.7% of patients and 41.7% of teeth exhibited recession at T3. The researchers compared these long-term measurements of gingival recession in orthodontically treated patients with findings reported by Albander and Kingman in untreated adults. Using data from the Third National Health and Nutrition Examination Survey, the investigators reported similar age-related gingival recession patterns.

The authors stressed that the “amount of mandibular incisor proclination during treatment was not related to the development of gingival recession.” In addition, the increases in recession observed at T3 appeared to be largely age related, they wrote. The authors concluded that “orthodontic treatment does not appear to be a risk factor for the development of gingival recession.”

Read the original article here.

Editor’s note: The articles in this issue address everyday issues in orthodontic practice. The first examines the possible effect of orthodontic treatment on gingival recession. The second article explores mandibular incisor crowding after orthodontic treatment and the potential influence of third molars. The third study looks at treatment timing for orthopedic expansion of the maxilla; although expansion during the mixed dentition stage likely is best, the authors examine suture patency and how long it remains amenable to expansion. The final article examines the Achilles heel of orthodontic treatment: the need for patient compliance, especially regarding removable appliances. The study findings support what experienced dental professionals know; we rarely get all we ask of patients in support of their dental care.


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


Do third molars affect mandibular incisor crowding after orthodontic treatment?

In this systematic review and meta-analysis, researchers explored the association between recurrent mandibular incisor crowding after orthodontic treatment and the presence of third molars. The study was published in the June issue of Journal of the World Federation of Orthodontists.

The investigators searched the following databases, with no limitation on year of publication or language: Scopus, PubMed, MEDLINE Complete, Web of Science, Embase, and Cochrane. They also conducted a hand search of references in the selected articles.
Inclusion criteria were clinical studies of patients receiving orthodontic posttreatment follow-up who underwent extraction of third molars compared with patients who did not undergo third-molar extraction. Crowding of the mandibular incisors in the posttreatment period was the main study focus, the authors wrote. Exclusion criteria were studies unrelated to the topic, studies of patients still receiving orthodontic treatment with a fixed appliance, studies of maxillary incisor crowding related to maxillary third molars, and studies of patients not undergoing orthodontic treatment.

Two researchers independently selected the articles for consideration. They first read the titles and abstracts and chose the articles that met the study criteria. Articles that did not contain sufficient information in the title and abstract were downloaded and read, allowing the researchers to decide whether to include them in the systematic review. The database searches identified 239 articles. Removal of duplicates and those that did not meet the eligibility criteria resulted in only 6 articles; 2 of these (with a total of 143 participants) were evaluated as having a low risk of bias and were included in the meta-analysis, the authors wrote.

The authors reported that 5 of the 6 studies in the systematic review used plaster models for evaluation purposes, 2 used panoramic radiography, 1 used interproximal force, 5 used cephalometric radiography, and 2 used other methods. Investigators in 1 study concluded that extracting third molars to minimize mandibular crowding was not applicable because no statistically significant differences were found between patients who underwent extraction and those who did not. Researchers in 4 studies concluded that third molars “exerted no influence on crowding in the mandibular arch,” while only 1 author believed that third molars exerted influence.

On the basis of the results of the systematic review and meta-analysis, the authors concluded that the presence of third molars had no effect on the index of irregularity and intercanine width but resulted in reduced arch length. They found no statistically significant differences in the degree of mandibular incisor crowding after orthodontic treatment between patients with third molars and those with congenital absence of third molars. Consequently, prophylactic extraction of these teeth to avoid mandibular incisor crowding is not indicated, they wrote.

Read the original article here.


ADA 2017 fees increase soon
Time is running out. Register for ADA 2017 before registration and course fees double on Friday, September 22 at 5 p.m. CDT.

Interested in attending the ADA annual meeting in Hawaii? ADA 2017 attendees will have the chance to register for ADA 2018 in Honolulu before registration opens to the public, allowing you to secure your first choice of courses and hotel room.

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Maturation stages of the midpalatal suture and nonsurgical rapid maxillary expansion

Rapid maxillary expansion (RME) is commonly used to correct maxillary constriction. However, nonsurgical RME can only be performed in patients who do not have a fully mature midpalatal suture (MPS). In this study, published in the July issue of American Journal of Orthodontics and Dentofacial Orthopedics, investigators sought to determine the maturation stages of the MPS in children aged 11 through 15 years and discussed implications regarding the timing of maxillary expansion.

The authors evaluated cone-beam computed tomographic (CBCT) scans of 84 children (40 boys, 44 girls) that were obtained from a dental diagnostic imaging center. Inclusion criteria were age 11 through 15 years and availability of CBCT images. Exclusion criteria were a history of orthodontic treatment or the presence of any dental appliance at the examination, cleft lip and palate, and syndromic conditions.

The CBCT images were obtained with an i-CAT scanner (Imaging Sciences International) with these specifications: 8.9 to 30 seconds’ acquisition time, field of view of at least 11 centimeters, and 0.2 to 0.3 millimeter voxel size. Patients were instructed to remain seated with their heads positioned so that the Frankfort horizontal facial plane was parallel to the ground and the median sagittal plane was perpendicular to the ground. The authors used Invivo5 software (Anatomage) to evaluate the images.

The investigators used Angelieri and colleagues’ protocol to classify the level of maturation of the MPS. Their skeletal maturation stages and descriptions related to increasing sutural fusion are as follows:

  • A: relatively straight high-density line at the midline;
  • B: scalloped high-density line at the midline;
  • C: 2 parallel, scalloped, high-density lines close to each other and separated in some areas by small, low-density spaces;
  • D: 2 scalloped, high-density lines at the midline on the maxillary portion of the palate that cannot be visualized in palatine bone;
  • E: the MPS cannot be identified (the MPS is mature and closed).

Stage C was the most prevalent at all ages (61.5% of 11-year-olds, 51.9% of 12-year-olds, 50% of 13-year-olds, 53.3% of 14-year-olds, and 35.3% of 15-year-olds), the authors wrote. In addition, through age 13 years, the stage C prevalence was similar for boys and girls. However, at age 14 years, stage C was observed in 62.5% of girls but in only 42.9% of boys; this difference is due to girls’ earlier physical maturation. Girls continued to show earlier MPS closure than boys through the end of the study at age 15 years.

According to the authors, the prognosis for adolescents undergoing RME is favorable, with significant skeletal gains. However, doubts persist regarding the prognosis in patients who have stopped growing, they pointed out. The authors concluded that RME is clinically successful in most young patients at stages A, B, and C. In this study, 76.2% of participants were in 1 of these 3 groups. The results of this study suggest that conventional, nonsurgical RME in patients older than 15 years is justified by a satisfactory prognosis when assessment of the MPS by means of CBCT indicates a stage of no greater than C.

Read the original article here.


Examining patient compliance with wear regimens for removable orthodontic appliances

The degree of compliance with wear regimens for removable orthodontic appliances can affect the success of orthodontic treatment. In this systematic review and meta-analysis, researchers assessed patient compliance with stipulated wear regimens. The study was published in the July issue of American Journal of Orthodontics and Dentofacial Orthopedics.

Eligible quantitative studies included randomized and nonrandomized controlled clinical trials, prospective cohort studies, and case series (minimum sample size = 20) incorporating objective data on compliance levels, the authors wrote. Qualitative studies that explored patients’ views and experiences, as well as interventions to improve compliance were also eligible. In addition, mixed-methods studies that met the inclusion and exclusion criteria also were included. Patients of any age treated with 1 of the following were eligible for the study: headgear, protraction facemask, chin cup, removable appliances, removable retainers, or fixed appliances with intraoral elastics.

After retrieving relevant abstracts, 2 authors independently identified studies that met the eligibility criteria and assessed their quality. They used the Cochrane Collaboration’s risk of bias tool to assess the quality of randomized controlled trials and included only studies at low or unclear risk in the meta-analysis. The authors assessed nonrandomized clinical trials by means of the risk of bias in nonrandomized studies of interventions (ROBINS-I) tool and included only studies of low or unclear risk of bias. Finally, they assessed the quality of mixed-methods studies using the mixed-methods appraisal tool.

A total of 4,269 records were identified from the literature search, the authors wrote. Among these, 80 full-text articles were assessed. Twenty-four of these articles met the eligibility criteria; 2 were randomized controlled trials, 21 were prospective cohort studies, and 1 was a mixed-method design.

The study results showed considerable discrepancy between objectively measured wear time and stipulated wear time for both intraoral and extraoral appliance types, the authors wrote. With respect to headgear, the discrepancy between actual and stipulated wear times in 6 studies (a total of 171 participants) was a mean of 5.81 hours per day (almost 50% of the 12 to 14 hours’ wear time usually stipulated). For functional appliances, the discrepancy was a mean of 5.71 hours per day (about one-third less wear time than usually stipulated). The authors reported smaller discrepancies between actual and stipulated wear times for maxillary removable appliances (3.53 hours per day) and Hawley retainers (4.58 hours per day). Despite these differences, meta-regression suggested that compliance was not directly related to the type of appliance (P = .211), the authors reported.

The authors also found a substantial discrepancy between objective measures of compliance and patient-reported compliance. For all types of appliances, self-reported wear times were consistently higher than objectively measured wear times, the authors wrote. On the basis of results from 5 studies, the mean patient-reported wear time for headgear was 5.02 hours higher per day than objective measures of wear time. In some studies, patients’ self-estimates were more than 200% higher than objectively measured wear times.

Regarding interventions to improve compliance, the authors identified 5 studies that explored this issue. Specifically, 2 studies reported a slight increase in compliance with wear of headgear and Hawley retainers when patients were aware they were being monitored with a timer. In addition, investigators in single studies reported some effectiveness of headgear calendars and conscious hypnosis in increasing wear time.

The results of this systematic review and meta-analysis point to suboptimal compliance with removable orthodontic appliance regimens. Patients wore appliances for considerably less time than that stipulated and routinely overreported the duration of wear, the authors wrote. They concluded that there is a “pressing need for robust prospective research addressing the potential value of novel means of enhancing compliance in orthodontics.”

Read the original article here.


Let go and live with less control

Do you feel overloaded with too many expectations and rules about how to live your life?

“As dental professionals, we are particularly prone to suffering because we think we are supposed to be the ones fixing others,” Dr. Lisa Knowles writes in her Dental Practice Success article, Let Go and Live With Less Control. She notes that about half of dentists under age 40 say it would be difficult for them to seek professional help.

Mindfulness and other coping techniques are “absolutely within reach” for overwhelmed dental professionals, Dr. Knowles writes, "and can be used to help ourselves and others."

Read more in the summer 2017 issue of Dental Practice Success.

DOS offers ‘once in a lifetime opportunity’ for children in need

The American Association of Orthodontists (AAO) sponsors Donated Orthodontic Services (DOS), a program to provide orthodontic care to low income children who lack insurance coverage or who do not qualify for other assistance in their states of residence.

Dentists are invited to refer potential patients to  The page includes a link to learn about eligibility requirements and an application. The program is administered for the AAO by Dental Lifeline Network.


Working together to make cancer history
As a dentist, you know that oral health is an integral part of overall health. The American Cancer Society estimates that there will be nearly 50,000 new cases of oral and oropharyngeal cancer in the U.S. in 2017.

A first-time ever symposium at ADA 2017 - America’s Dental Meeting brings together experts from the University of Texas MD Anderson Cancer Center, University of Chicago, Centers for Disease Control and Prevention and the American Dental Association’s Science and Practice Institutes to address the relationship between HPV infection and oropharyngeal cancer, and how health professionals can work together to help reduce cases and provide better treatment results for patients.

Let’s work together to make cancer history.


JADA+ Specialty Scans and JADA+ Scans

JADA+ Specialty Scans and JADA+ Scans are quarterly newsletters updating dentists on the latest research in selected specialties and disciplines in dentistry. ADA Publishing and the consulting editors from the represented specialties and disciplines aggregate and summarize research from previously published materials, each item attributed to its publication of origin. JADA+ Scan specialties and disciplines include endodontics, oral pathology, orthodontics, pediatric dentistry, periodontics, prosthodontics, radiology, cosmetic/esthetic and osseointegration. 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. View past issues here.

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