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

Duration of orthodontic treatment with fixed appliances and gingival enlargement

In a study published in the October issue of American Journal of Orthodontics and Dentofacial Orthopedics, investigators examine the association between duration of orthodontic treatment with fixed appliances and gingival enlargement (GE) in adolescents and young adults.

This cross-sectional study included 260 patients (aged 10 to 30 years) who sought or were receiving orthodontic treatment at a graduate orthodontic program in Santa Maria, Rio Grande do Sul, Brazil. The researchers stratified participants into 4 groups (n = 65 each) according to treatment duration.

  • G0 (control group): patients previously examined for orthodontic treatment with fixed appliances;
  • G1: patients undergoing orthodontic treatment for 10 through 14 months (1 year);
  • G2: patients undergoing orthodontic treatment for 22 through 26 months (2 years);
  • G3: patients undergoing orthodontic treatment for 34 through 38 months (3 years).

Researchers excluded patients who needed traction on impacted teeth or more than 2 millimeters of buccolingual repositioning; patients with congenital abnormalities, systemic illness, or cysts; patients with special needs or who used systemic medication for treatment of chronic diseases that might interfere with gingival overgrowth; and patients who needed chemoprophylaxis before the clinical examination.

At the outset of the study, participants completed a structured questionnaire regarding sociodemographic characteristics and oral hygiene habits, the authors wrote. One examiner performed all clinical examinations using a dental mirror, a Williams periodontal probe, and a World Health Organization probe. The examination included assessment of plaque according to the Löe and Silness plaque index, a gingival assessment according to the Löe gingival inflammation index, and assessment of GE in the anterior segment according to the Seymour index. The Seymour index is a combined score of increased gingival thickening and encroachment of the papilla onto the adjacent crown; the researchers used it to evaluate papillae among the 6 anterior teeth.

The researchers found no differences in GE scores among the 4 groups with respect to sex, mother’s education, or toothbrushing frequency. The study findings showed that clinically relevant GE was significantly associated with treatment duration. Compared with participants in the control group (G0), those who underwent orthodontic treatment with fixed appliances for 1, 2, or 3 years were at an increased risk of developing GE. The authors reported results in terms of rate ratios (RRs), which are calculated by dividing the rate of GE in the treatment group (G1, G2, G3) by the rate in the control group (G0). The study findings were RR (95% confidence interval [CI]), 22.9 (10.2 to 51.4) for G1; RR (95% CI), 32.5 (14.6 to 72.2) for G2; and RR (95% CI), 35.2 (15.9 to 78.0) for G3.

When sociodemographic characteristics, self-reported oral hygiene habits, and clinical variables were added to the regression model, the researchers observed a slight decrease in the GE risk estimates. The adjusted estimates showed that patients undergoing orthodontic treatment for 1, 2, or 3 years had a 20- to 28-fold increased risk of developing GE, the authors wrote. In addition, adjusted estimates showed that patients’ ages and gingival inflammation were significantly associated with the extent of anterior GE. As might be expected, adolescents and those with higher gingival inflammation levels had more GE.

The authors pointed out that the cross-sectional study design was a limitation. To verify whether GE increases over time, the same patient should be monitored during treatment.

The researchers concluded that the extent of anterior GE was significantly associated with treatment duration. Oral hygiene instructions should target adolescents and young adults undergoing orthodontic treatment.

Read the original article.

Editor’s note: The first article in this issue shows an association between duration of fixed appliance treatment and gingival problems, especially in adolescents. The second article provides a research base for additional intervention in patients who are susceptible to white-spot lesions. These 2 studies highlight the importance of the oral health care team in motivating patients to adhere to oral hygiene instructions to reduce treatment duration. The third article focuses on treatment timing. So much of what orthodontists can do is tempered by the need to do the right things at the right time, maximizing the effects and minimizing active treatment time. The final article addresses long-term use of oral appliances for sleep apnea, a treatment that has helped many patients. Oral appliances often are identical to functional orthodontic appliances that are used to correct Class II malocclusion (that is, positioning a relatively retruded mandible into a “forward” bite). The 10-year study reported here is 1 of several that demonstrate dental changes similar in direction to those reported during active orthodontic treatment with functional appliances. As more oral appliances are used to treat sleep apnea and long-term patient data are collected, other adverse effects are likely to be identified, of which clinicians and patients need to be aware.


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


Remineralization of enamel subsurface lesions treated with casein phosphopeptide–amorphous calcium phosphate and fluoride toothpaste

Orthodontic patients are at a higher risk of developing white-spot lesions than people who do not undergo orthodontic treatment. In this randomized, controlled crossover trial, researchers investigated the remineralization of enamel subsurface lesions treated with casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) in addition to fluoride toothpaste.

In this 6-month in situ study, researchers created artificial carious lesions in nonrestored premolars extracted as part of orthodontic treatment. Any teeth with cracks, caries, or surface irregularities were excluded, the authors wrote. After lightly abrading the teeth with fine abrasive paper to remove the outermost enamel and pellicle layer, the researchers immersed the teeth in an acid buffer demineralizing gel for 5 to 7 days. They then divided the enamel block containing the lesion into 3 sections: 1 for use as a control and 2 experimental sections.

To enclose the enamel sample for attachment to a patient’s archwire, the authors used a stainless-steel carrier, which they placed in the mandibular premolar region. The enamel sample with the artificially demineralized enamel (comparable with a carious lesion) was then subjected to the patient’s oral environment for the duration of the study.

The study sample consisted of 12 patients receiving fixed orthodontic treatment at Liverpool University Dental Hospital in Liverpool, United Kingdom. Inclusion criteria were ages 12 through 17 years, receipt of mandibular fixed appliance therapy with a 0.019- × 0.025-inch stainless steel archwire, adequate space for placement of the carrier, and good general and oral health. Exclusion criteria were an allergy to milk products (a contraindication with the commercial CPP-ACP product), receipt of antibiotic treatment in the previous 2 months, and inability to maintain adequate oral hygiene.

The randomly administered interventions were fluoride toothpaste (1,450 parts per million) and fluoride toothpaste in combination with topically applied CPP-ACP (10% weight per weight, Tooth Mousse, GC Europe). The study regimen consisted of 4 distinct 4-week phases: pretrial washout (fluoride toothpaste only), first intervention, midtrial washout (fluoride toothpaste only), and second intervention, the authors wrote. Thus, during 1 of the 2 intervention periods, patients carried the enamel sample while using fluoride toothpaste only; during the other intervention period, they carried the enamel sample while using fluoride toothpaste plus CPP-ACP.

To evaluate baseline lesions and posttreatment in situ lesions, the investigators used transverse microradiography, a quantitative method regarded as the criterion standard for remineralization-demineralization studies. Analysis of mineral content resulted in 3 main measures: mineral loss, lesion depth, and lesion width.

The study findings showed that the fluoride toothpaste treatment group experienced a mineral gain of 15.4%, whereas the fluoride toothpaste plus CPP-ACP treatment group experienced a mineral gain of 24.6%. This difference was statistically significant (P = .023). At baseline, the mean lesion depth in the fluoride toothpaste group was 59.7 micrometers. After treatment, the mean lesion depth was 58.3 μm, for a 1.4-μm reduction. In the CPP-ACP group, the mean lesion depth at baseline was 58.3 μm, and the mean posttreatment lesion depth was 52.4 μm, a reduction of 5.9 μm. Again, the between-group difference was statistically significant (P = .037). Finally, mean lesion width was reduced by 2.5 μm in the fluoride toothpaste group, a 4.5% reduction from the mean baseline value. In the fluoride toothpaste plus CPP-ACP group, mean lesion width was reduced by 7.6 μm, a 15.3% reduction from the mean baseline value. This difference also was statistically significant (P = .015).

The results of this study suggest that topical application of CPP-ACP combined with regular use of fluoride toothpaste may have a better remineralization effect on subsurface enamel lesions than use of fluoride toothpaste alone. Therefore, clinicians can recommend its use in patients at high risk of developing demineralization or in those who have exhibited early signs of white-spot lesion formation.

Read the original article.


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Assessing the timing of orthodontic treatment for malocclusions

The timing of orthodontic treatment—especially treatment requiring dentofacial orthopedics—for different types of malocclusions is important and requires identification of specific growth phases. In this review article, researchers examine various growth indicators and their reliability in identifying the pubertal growth spurt, as well as the prepubertal and postpubertal growth phases. This study was published in the September issue of Journal of the World Federation of Orthodontists.

Several growth indicators are available to aid clinicians and researchers in identifying circumpubertal growth phases. The authors described the following growth indicators currently being used and explored their reliability.

  • Hand and wrist maturation (HWM). The method proposed by Fishman1 consists of 11 stages. Investigators have reported a good correlation between these stages and the pubertal growth phase, as defined by the mandibular growth peak. This method is sometimes called the skeletal maturation assessment.
  • Third finger middle phalanx maturation (MPM). This method can be used in any clinical setting with minimal instrumentation and radiation exposure. However, evidence regarding the efficacy of the MPM method is sparse.
  • Cervical vertebral maturation (CVM). The method proposed by Baccetti and colleagues2 consists of 6 stages (1 and 2 are prepubertal, 3 and 4 are pubertal, and 5 and 6 are postpubertal). One advantage of CVM is the availability of pretreatment lateral head radiographs for orthodontic patients, eliminating the need for additional radiographs. However, the authors noted that clinical studies are at variance regarding the correlations between mandibular growth peak and progression of CVM stages.
  • Dental maturation. The authors noted that this method has the least clinical applicability for growth guidance.
  • Chronological age. According to the authors, clinical applicability of chronological age as an indicator of the pubertal growth phase is limited.
  • Standing height. This method involves recording standing height at regular intervals. The authors pointed to studies showing satisfactory correlation between standing height peak and mandibular growth peak. However, this method is of limited feasibility in clinical practice.
  •  Biochemical markers. Use of biomarkers has been proposed as an aid in assessing skeletal maturity. However, clinical applicability is limited to date, primarily owing to the lack of chairside testing kits and reference values.

The authors also discussed several types of common skeletal and dental malocclusions, treatment modalities, and optimal timing of interventions. Transverse maxillary deficiency is a common malocclusion. Unilateral or bilateral crossbite affects up to 15% of schoolchildren. Although the literature contains few long-term studies of the skeletal effects of rapid maxillary expansion (RME), the results of a study3 showed the benefits of prepubertal treatment compared with postpubertal treatment, the authors wrote. Therefore, the authors recommended early treatment of transverse maxillary deficiency. Whenever possible, clinicians can use chronological age and dentition phase (up to the mixed dentition) to assess the timing of RME in younger patients. In older patients, radiographic growth indicators, such as HWM, MPM, and CVM, should be used.

Palatal canine displacement is a disorder that often precedes tooth impaction. A study by Sigler and colleagues4 indicates that RME in conjunction with extraction of primary canines in the prepubertal growth phase increases the eruption rate of permanent canines by up to 80%. Clinicians and researchers can assess prepubertal growth phase by means of CVM, MPM, and HWM, the authors wrote.

According to meta-analyses5,6 cited by the authors, functional treatment for skeletal Class II malocclusion is most successful during the pubertal growth phase. The HWM or CVM methods can be used to assess skeletal maturation, and the MPM method can be used to identify the mandibular growth peak.

Study findings7,8 show that skeletal Class III malocclusion should be treated early in life, the authors wrote. RME and face-mask protraction during the prepubertal growth phase have resulted in mandibular and maxillary growth correction. In young patients, chronological age and dentition phase can be used to time the intervention, while in older patients, radiographic indicators, such as HWM, MPM, and CVM methods, can be used.

The timing of treatment in relation to a patient’s stage of growth and development is important. Despite the limited evidence to date, the authors recommended combinational use of growth stage indicators in clinical practice and research for malocclusions that require interceptive treatment, functional treatment, or both.

Read the original article.

  1. Fishman LS. Radiographic evaluation of skeletal maturation: A clinically oriented method based on hand-wrist films. Angle Orthod. 1982;52(2):88-112.
  2. Baccetti T, Franchi L, McNamara JA Jr. The cervical vertebral maturation (CVM) method for the assessment of optimal treatment timing in dentofacial orthopedics. Semin Orthod. 2005;11(3):119-129.
  3. Baccetti T, Franchi L, Cameron CG, McNamara JA Jr. Treatment timing for rapid maxillary expansion. Angle Orthod. 2001;71(5):343-350.
  4. Sigler LM, Baccetti T, McNamara JA Jr. Effect of rapid maxillary expansion and transpalatal arch treatment associated with deciduous canine extraction on the eruption of palatally displaced canines: A 2-center prospective study. Am J Orthod Dentofacial Orthop. 2011;139(3):e235-e244.
  5. Perinetti G, Primozic J, Franchi L, Contardo L. Treatment effects of removable functional appliances in pre-pubertal and pubertal Class II patients: A systematic review and meta-analysis of controlled studies. PLoS One. 2015;10:e0141198.
  6. Perinetti G, Primozic J, Furlani G, Franchi L, Contardo L. Treatment effects of fixed functional appliances alone or in combination with multibracket appliances: A systematic review and meta-analysis. Angle Orthod. 2015;85(3):480-492.
  7. Westwood PV, McNamara JA Jr, Baccetti T, Franchi L, Sarver DM. Long-term effects of Class III treatment with rapid maxillary expansion and facemask therapy followed by fixed appliances. Am J Orthod Dentofacial Orthop. 2003;123(3):306-320.
  8. Cha KS. Skeletal changes of maxillary protraction in patients exhibiting skeletal class III malocclusion: A comparison of three skeletal maturation groups. Angle Orthod. 2003;73(1):26-35.



Evaluating tooth position and occlusion after long-term use of a mandibular protruding device

In patients with sleep apnea or snoring problems, use of a mandibular protruding device (MPD) may be an alternative to continuous positive airway pressure therapy. In this study, published in the October issue of European Journal of Orthodontics, researchers measured and evaluated tooth position and occlusion in patients after 10 years of using an MPD at night.

This prospective observational study was composed of patients who had been fitted with an MPD 10 years earlier at the Department of Stomatognathic Physiology in Örebro, Sweden. At the 10-year clinical follow-up appointment, all patients were invited to participate in a follow-up study. Of the 74 patients, 60 (13 women and 47 men) agreed to participate. The authors reported that 41 of the 60 patients (68%) continued to use the MPD device at the 10-year follow-up, while 19 (32%) had stopped using the device. Inclusion criteria were a signed informed consent form and dental casts of sufficient quality from the baseline and 10-year follow-up appointments.

The authors described the MPD as a removable monobloc appliance made of heat-cured methyl methacrylate resin. The device was designed to position the mandible forward about 75% of the maximum range of protrusion with a minimum of 5 millimeters of protrusion. The MPD covered all occlusal surfaces and the incisal edges in the maxilla and mandible, the authors wrote.

One clinician conducted all of the clinical examinations and obtained alginate impressions of the jaws. A second researcher obtained all of the measurements and analyzed all of the dental casts using digital calipers to measure distances and lengths to the nearest 0.1 mm.

The participants completed a questionnaire that assessed patients’ compliance with the MPD wear regimen. Answer choices were “seldom/never,” “once or twice a month,” “once a week,” “several times per week,” or “every night.” Thirty-seven patients reported that they wore the MPD every night, and 4 stated that they wore it several times a week.

The authors reported that current MPD users experienced a significant decrease in overjet during the 10-year treatment period (mean change, –1.8 mm; 95% confidence interval [CI], –2.5 to –1.2 mm; P < .001). In contrast, patients who had stopped wearing the MPD experienced a small, nonsignificant decrease in overjet (–0.3 mm; 95% CI, –0.6 to 0.1 mm). In addition, both groups experienced a significant decrease in overbite, but the decrease was greater in current MPD users (–1.5 mm; 95% CI, –1.9 to –1.0; P < .001) than in those who stopped wearing the device (–0.6 mm; 95% CI, –0.9 to –0.2; P < .01), the authors wrote.

The 10-year follow-up examination also revealed that 13 current MPD users (33%) had developed bilateral posterior infraocclusion during the treatment period, whereas none of the participants who stopped using the device had developed this malocclusion, the authors wrote.

Current MPD users also experienced a significant decrease in maxillary and mandibular intercanine width, likely due to a mesial drift of the dentition, the authors wrote. In contrast, nonusers experienced nonsignificant changes in intercanine width. Regarding intermolar width, current MPD users experienced nonsignificant changes, but patients who had stopped using the device experienced a significant increase (0.8 mm) in mandibular intermolar width and a nonsignificant decrease (–0.4 mm) in maxillary intermolar width.

As these study results indicate, occlusal changes frequently occurred in participants during the study period despite the MPD’s full occlusal coverage of all teeth, which was intended to minimize dental changes, the authors wrote.

Overjet and overbite were the most significant occlusal changes in patients who used an MPD over the 10-year study period. The authors reported that MPD wear could also lead to posterior infraocclusion. They concluded that because of the mesial drift of the mandibular teeth, patients with a Class III relationship might not be suitable candidates for MPD treatment.

Read the original article.


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AAO, AAPD plan Joint Winter Conference for February 2018

“Early Orthodontic Treatment: Working Together for Excellent Results” is the theme of the upcoming Joint Winter Conference of the American Association of Orthodontists and the American Academy of Pediatric Dentistry. The meeting will be held at the Westin Kierland Resort and Spa in Scottsdale, Arizona, February 9-11, 2018.

Among topics to be explored by experts from the U.S. and worldwide are: care for dental injuries and trauma; incipient impaction and potential strategies for prevention; malformed first molars and missing premolars; insights into treatment of patients on the autism spectrum; and risk management. View the preview program and link to registration here. Registration is open; register by 5 p.m. Central time on Friday, January 12, 2018, to qualify for the early registration fee. Sixteen continuing education credit hours are available at this meeting.


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Dental Practice Success is designed with our member dental professionals in mind. This e-Pub features must-read articles that offer the member dentist resources and information to help them succeed as dental practitioners and small business owners. Dental Practice Success is emailed quarterly.


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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