This is the final report on an innovative study first published in the summer of 2023. I have posted about these two papers before. They focused on treatment outcomes at the end of the functional phase. The first paper examined the patient’s perception of their treatment. The second reported on dental and skeletal effects. This new paper provides useful information from the end of treatment. 

A team in London, in south-east England, conducted this study. The Angle Orthodontist published the paper. 

Comparison of the effects of Hanks Herbst vs twin block following the removal of fixed appliances in Class II correction: a randomized controlled trial

Ama Johal et al.

Angle Orthodontist: Advance access. 

I have a conflict to declare. I know this study team well.

What did they ask? 

They did this study to. 

“Compare the effectiveness to the completion of active treatment of undergoing an initial phase of fixed or removable functional appliances, followed by comprehensive fixed appliance therapy.” 

What did they do? 

They did a parallel-group, two-arm randomised controlled trial with a 1:1 allocation ratio. 

Recruitment began in February 2017 and concluded in 2019. The study was conducted in the orthodontic department of Queen Mary University of London, UK. One operator treated all patients.

The PICO was

Participants

Orthodontic patients aged 10-14  with Class II Division 1 incisal relationship and an overjet greater than 7mm.

Interventions

Standard modified Twin Block appliance. The clinician asked patients to wear their appliances full time except during meals and sports.

Comparison

Hanks Herbst fixed functional appliance. With bands on the first molars, lingual and palatal arches (or RME). The operator cemented the appliance with glass ionomer cement.

Outcomes

The primary outcome was the time taken to reduce the overjet to less than 4 mm. Secondary outcomes included skeletal or dental changes, occlusal index scores, treatment duration and failure, and health-related quality of life. 

Records were collected at the start of treatment (T0), at the end of functional appliance treatment (T1), and at T2 following removal of fixed appliances. The clinician defined the final endpoint as normal occlusion and alignment with adequate intercuspation. I was a little confused by this, as I was unsure how it related to the primary outcome of overjet less than 4 mm.

They analysed the cephalograms with the Pancherz analysis. They also analysed the study models with the Peer Assessment Rating. Finally, they used several quality-of-life questionnaires. 

One operator treated all patients with appointment intervals of 6-8 weeks. They removed the appliance when the overjet had reduced and appeared stable. They classified a patient as non-co-operative if the overjet had not reduced by 10% in 6 months, or if they had not achieved a normal overjet after 12 months.

The study statistician carried out both univariate and multivariate analyses. They also conducted a sample size calculation. This suggested that they needed to enrol 40 patients into each intervention group.

The randomisation was pre-prepared, and they concealed the allocation in sealed envelopes.

What did they find?

According to earlier reports on this study, 80 participants were enrolled. When they reviewed the completion rate in the Twin Block group, they reported that 2 participants did not reduce their overjet after 6 months due to poor compliance. 13 other participants failed to achieve the desired overjet reduction. This resulted in a total of 15 failures (37.5%).

When they looked at similar data for the Herbst group, no dropouts were reported, but treatment was stopped in 7 participants (17.5%) because of poor oral hygiene, frequent breakages, and/or other complications. 

The mean duration of treatment, from the end of the functional phase to completion of the fixed appliance, was 28 months for the Herbst group and 26.9 months for the Twin Block group. I reviewed the previous reports on this study, which showed that the duration of Herbst treatment was 8.8 months and, for the Twin Block, 10.3 months. These are long treatment times. 

When they examined skeletal and dental changes using cephalometric measurements, they found no clinically significant differences at the end of fixed-appliance treatment. Similarly, the Peer Assessment Rating scores did not differ. The mean end-of-treatment PAR score was 4.1 for the Twin Block group and 4.6 for the Herbst group. Oral health quality of life scores did not differ, except that Twin Block patients reported more embarrassment than the Herbst group. 

The skeletal, dental and occlusal outcome measurements were almost identical to those that we reported in our large trial into similar appliances.

Their final conclusion was 

” Both the Twin Block and the Herbst appliances were effective in correcting the Class II division I malocclusion, with long-term skeletal and occlusal outcomes largely comparable. However, the Herbst appliances achieve greater short-term improvements and are associated with fewer compliance issues and less reported embarrassment. This may suggest improved overall acceptability”.

What did I think? 

I have posted about this study twice before. I think it is an excellent study that provides us with a great deal of information about our choice of functional appliances. The results should be considered alongside the other two papers, which, interestingly, showed few differences between the appliances. It is rather unusual for a functional appliance study to report outcomes at the end of treatment. In this respect, this study adds considerably to the literature. 

While the two sets of appliances showed no meaningful differences in overall outcomes, one interesting point is the discontinuation rate. This was difficult to determine from the data in the paper because the authors did not provide a CONSORT flow diagram. However, they reported overall discontinuation rates that were generally similar to those in other studies. Some may expect these rates to be rather high. However, this is a real-world study and provides us with fairly strong data. It is also similar to the discontinuation rates we reported in our Herbst versus Twin Block study published many years ago. 

When we consider the differences in discontinuation rates, the Herbst appliance clearly has lower discontinuation. It is also interesting to note that patients felt more embarrassed with the Twin Block than with the Herbst appliance. This could explain the differences in cooperation. 

Final comment 

This is a really interesting study that was well carried out and reported. It provides a large amount of information that we should find useful when consenting patients for treatment. When I was a practising orthodontist, I always preferred the Twin Block appliance over the Herbst appliance because I felt it had fewer complications. It is interesting to see that these findings are still borne out. However, we need to accept a higher discontinuation rate with the removable appliance compared with the fixed appliance. This study provides very useful information for our patients. 

Overall summary

When I combine the findings from the three papers. I think that these are the main conclusions of this research

In Phase I, the Herbst appliance reduced overjets more quickly than the Twin Block. However, it had a greater dentoalveolar effect, as shown by flared lower incisors. Herbst treatment was 1.5 months faster. Nevertheless, there were more emergency visits.

At the conclusion of all treatment, there were minimal differences in treatment effects and quality-of-life measures. Importantly, the Twin Block had a higher discontinuation rate. Our patients may find the Herbst appliance more acceptable than the Twin Block.

       

Comments

• In reply to Byron Bonebreak. Spot on! Do what you can with ... by Dr Danny Radnzic
• In reply to Michael Zuk. Yes, I did not mention this because ... by Kevin O'Brien
• In reply to Byron Bonebreak. Great comment that sums it all ... by Kevin O'Brien
• Over the decades there have been numerous appliances used for ... by Byron Bonebreak
• The discussion avoided the typical claims of lower jaw growth ... by Michael Zuk

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It was therefore very interesting to see this new study in which a group of Italian-based investigators developed a prediction model to assess the effectiveness of MARPE. 

Prediction model for miniscrew-assisted rapid palatal expansion failures in late adolescent and adult patients

Marco Migliorati et al

AJO-DDO Advance access DOI: https://doi.org/10.1016/j.ajodo.2026.07.019

What did they ask?

In a thorough literature review, the team found that age influences the MARPE failure rate. However, the level of evidence supporting this is not high. As a result, they conducted this study to

“Establish and develop a statistically based framework for predicting expansion outcomes in MARPE”.

What did they do? 

They conducted a prospective observational study of 69 consecutively treated MARPE patients. 

The inclusion criteria were full permanent dentition, age over 16 years, and the need for maxillary expansion. A pretreatment CBCT scan was also required. 

Experienced operators treated the at four centres, and operators used the same expansion device. This incorporated four mini-screws and one expansion screw, without dental or resin anchorage. They activated the appliances by turning the screw until the the achieved sufficient expansion. 

The primary outcome was MARPE failure.  The team defined this as the clinical absence of mid-palatal suture opening, indicated by the absence of an interincisal diastema. 

They collected data on gender, age, multiple CBCT predictors, and bone quality. 

They carried out the usual univariate statistical analysis, followed by logistic regression to identify predictors of expansion failure. 

What did they find? 

The study included 69 patients. These were divided into 38 males and 31 females, with a mean age of 23.5 years. Of these, 39 were treated at the principal centre, and 12, 9, and 9 were in the other three centres. 

The overall failure rate was 33%. By gender, the failure rate was 50% in males and 13% in females. 

They used their regression model to generate predictors of the failure rate. This showed that the failure rate was higher in males and increased with age, whereas this trend was not observed in females. It was interesting to see that the probability of failure for males was approximately 50% at 22 years, whereas for females it remained 20% across the entire age range. 

Importantly, the suture maturation evaluation did not show any significant effect. 

Their overall conclusions were 

“The effectiveness of MARPE decreased with increasing age in late adolescents and adult patients. The failure rate appeared higher in male patients after age 22. The failure rate reached 50% and continued to increase with age”.

What did I think? 

There is no doubt that this technique and other forms of expansion need high-quality research. As a result, it was good to see this excellent exploratory investigation. It is also important to note that this is a prospective study and is a higher level of evidence than retrospective studies.

The results are interesting and clinically useful. They certainly do not align with the claims made by case reports. Other systematic reviews and retrospective studies also suggest an 80% to 90% success rate with MARPE. Nevertheless, these reviews have included mostly retrospective studies. This study clearly adds to our knowledge by providing higher-level evidence. 

The authors highlighted several limitations. I think the most important is their definition of failure, which was limited to the absence of a midline diastema. Importantly, they did not obtain an end-of-treatment CBCT to assess palatal suture opening. However, I doubt that this would have been ethical. In this respect, I feel that the outcome was clinically relevant, and we should consider this valid.

I would also have liked to see some information on success rate by operator or clinic. This is important because there was an imbalance in numbers between the clinics, and this may suggest that the operator who placed 39 appliances may be more experienced than those who placed fewer. This may, of course, influence the success rates, particularly if one of the low-output clinics treated more older males than the others. 

Final thoughts

This study has some minor deficiencies, but it provides us with useful information, particularly with respect to the effects of age and potentially gender on the success rates of MARPE. As a result, it provides us with useful data that we can share with our patients when we obtain their consent to this form of treatment. 

       

Comments

• In reply to Anonymous. Thanks, I’ll take your point on ... by Kevin O'Brien
• A MARPE that is not connected to the teeth, has only 4 screws, ... by John McDonald
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• My problem with your blogs, Dr. O’Brien, is statements like ... by Anonymous

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I came across this post on the excellent yONE platform that Bjorn has set up. yONE is a closed learning community built around short, regular teaching impulses. Björn sees the whole programme as a new way to organise continuing education: small, frequent opportunities to learn, connected to a community of colleagues.

His posts are easy to read and highlight main issues with limited additional text. They are clear and to the point. I thought I should post this example, as it clearly addresses the complex situation of MARPE and the airway.

Introduction

The updated American Association of Orthodontists white paper on sleep-disordered breathing, recently published in the *American Journal of Orthodontics and Dentofacial Orthopedics*, is unusually clear.

Martyn Cobourne has already provided an excellent summary of this paper onthis blog. I do not want to repeat it. Instead, I would like to discuss whatis happening outside the scientific literature—in our clinics, inboxes andsocial media feeds.

We now receive enquiries almost every week from adults asking specifically for MARPE to improve their airway.

Importantly, they are not asking whether they have a transverse maxillary deficiency.

They are asking for the appliance.

What does the white paper tell us?

The main conclusions are pragmatic:

• Sleep-disordered breathing is a medical disorder.
• Medical diagnosis should precede an intervention intended to treat it.
• The orthodontist’s primary roles are screening, risk recognition, referral and interdisciplinary collaboration.
• No orthodontic intervention has been shown to prevent the development of sleep-disordered breathing.
• Orthodontic treatment is not supported as a stand-alone treatment for sleep-disordered breathing.
• No currently known craniofacial phenotype can reliably identify its presence.
• Cephalometric or CBCT airway dimensions are unsuitable for diagnosis, risk assessment or evaluation of treatment success.
• Routine frenectomy is not supported for the prevention or treatment of sleep-disordered breathing.
• Current evidence does not demonstrate that orthodontic extractions or distalisation cause sleep-disordered breathing.

This does not mean orthodontists have no role. It means that our role must begin with diagnosis—not with an appliance.

From expansion to human optimisation

The scientific message is cautious. The online message is rather different.

MARPE and other “airway” treatments are associated online with an expanding list of benefits:

• improved nasal breathing;
• elimination of mouth breathing;
• reduced snoring;
• deeper and more restorative sleep;
• improved daytime energy;
• reduced fatigue and brain fog;
• better concentration and memory;
• improvement of ADHD-like symptoms;
• improved academic performance;
• fewer headaches and migraines;
• improvement of posture and temporomandibular symptoms;
• better athletic performance;
• broader smiles, stronger cheekbones and a more attractive face.

Not every clinician makes all these claims, and some are carefully qualified. Nevertheless, the combined social-media narrative is powerful: widen the maxilla, enlarge the airway and improve the person. At the more extreme end of the wider “airway wellness” ecosystem, better breathing becomes connected with hormonal health, immunity, digestion,fertility, sexual performance and even intelligence.

At this point, an orthodontic appliance is no longer being marketed as an orthodontic appliance. It has become a form of human optimisation.The difficulty is that these claims often combine several individually plausible steps into one apparently certain conclusion:

1. Expansion changes anatomy.
2. Anatomy influences breathing.
3. Breathing influences sleep and general health.
4. Therefore, expansion must improve sleep and general health.

Each step may sound reasonable. The complete causal chain, however, has not been demonstrated.

The treatment has already been selected

A recent enquiry from a 34-year-old patient illustrates the problem.

Before requesting an examination, the patient had already decided that:

• the maxilla required skeletal expansion;
• MARPE was the preferred treatment;
• mini-implants under local anaesthesia were acceptable;
• surgically assisted expansion was not;
• and improvement in breathing was an expected outcome.

The patient then asked four intelligent questions:

1. How many adults over 30 have you treated this way?

2. In how many did the midpalatal suture open without surgery?

3. Should I send a CBCT before the consultation?

4. What happens if the suture does not open?

These are reasonable questions.

But the most important question was missing:

“Do I have a transverse maxillary deficiency that requires treatment”?

The procedure had been selected before the diagnosis. The expected health benefit had been accepted before the evidence had been discussed. The appliance had become the diagnosis.

What can MARPE achieve?

MARPE is an important and valuable orthodontic technique. In a carefully selected adult with a genuine transverse skeletal discrepancy, it may produce clinically useful skeletal expansion and reduce unwanted dental effects compared with purely tooth-borne expansion.

However, nonsurgical suture opening cannot be guaranteed. Chronological age is only one of several relevant factors, and treatment may fail or produce an unfavourable response. Patients must understand the uncertainty and the possible need for an alternative or surgically assisted approach.

Expansion should therefore be prescribed because the patient has a diagnosed transverse problem—not because an airway rendering looks narrow or because the patient hopes to sleep, think or perform better.

The white paper makes another important distinction: an increase in nasal oropharyngeal volume does not automatically demonstrate improved respiratory function.

A colourful before-and-after CBCT image may be impressive.

It is not a sleep study.

It does not diagnose obstructive sleep apnoea, quantify its severity or prove that it has been successfully treated.

The paper also states that the additional effect of skeletal anchorage during expansion on breathing has not yet been objectively assessed. This is particularly relevant to the claims surrounding MARPE.

More skeletal expansion does not automatically mean more functional improvement.

This is not the patient’s fault

I do not blame patients for arriving with these expectations. They are responding logically to the information presented to them. If clinicians, influencers, podcasts and animated airway images repeatedly connect a narrow maxilla with poor sleep, reduced concentration, impaired development and long-term systemic disease, patients will understandably search for the appliance that promises to correct everything. They may even interpret a clinician who recommends proper diagnostics—or questions the indication—as being old-fashioned or insufficiently “airway aware”.

Our responsibility is to slow the process down.

Before discussing an expander, we should ask:

1. Is there a genuine transverse orthodontic discrepancy?

2. Is sleep-disordered breathing suspected or medically diagnosed?

3. What precise outcome are we attempting to achieve?

If a transverse discrepancy exists, we can discuss expansion on its orthodontic merits. If sleep-disordered breathing is suspected, the patient requires appropriate medical assessment and, when indicated, objective sleep testing.

Both problems may coexist.

But one does not diagnose the other.

What do I think?

The current enthusiasm for airway health contains something positive. Orthodontists are looking beyond tooth alignment, asking broader questions and collaborating more closely with medical colleagues.

But good intentions do not replace evidence. MARPE does not become an airway treatment simply because airway volume increases. It does not become preventive medicine because an attractive biological explanation can be constructed around it. And it does not become risk-free because surgery has been excluded from the patient’s preferred treatment menu.

We should

• treat genuine transverse discrepancies.
• screen for sleep-disordered breathing.
• refer and collaborate when appropriate.

But we should not manufacture an airway diagnosis to justify an appliance—or promise systemic health benefits that have not been demonstrated.

MARPE is an appliance.

It is not a diagnosis.

Airway is not a treatment menu.

*Björn Ludwig is an orthodontist in Traben-Trarbach, Germany

       

Comments

• Fabulous Post! I really appreciate the thoughtful orthodontic ... by James Patrick Murphy DMD
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• Excellent article! Now if only the Instagram crew would stop ... by ashley Smith
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This is a guest post by Dr Klaus Batista, who is Adjunct Professor at the School of Dentistry Rio De Janeiro University, Brazil. He is developing a reputation on AI in orthodontics.

Responsible integration of artificial intelligence in clinical care: An American Association of Orthodontists position paper

Heather Hopkins et al

AJO-DDO Advance access: access. Let’s take a look.

https://doi.org/10.1016/j.ajodo.2026.04.008

Introduction

Before starting, I’d like to clarify what a position paper means. One common definition is:

“A detailed report that recommends a course of action on a particular issue.”

It is relevant to point out that the recommendations in this position paper were developed by the AAO Task Force on Artificial Intelligence in Orthodontics. Although a position paper is not a high-level research paper, it is intended to provide relevant guidance for the responsible adoption of AI technologies in orthodontic clinical care.

Is this important?

AI has become a field of great interest worldwide. In orthodontics, there are several interesting uses of AI, such as orthodontic monitoring, cephalometric tracing, diagnosis, and treatment planning. Concerns arise about AI autonomy and the potential risk to patients from the lack of human participation in the process. Humans remain ultimately responsible for the final decision-making.

The Authors

The task force was composed of people from diverse backgrounds: private practitioners, academic orthodontics departments, the American Board of Orthodontists, AAO staff, and AI and digital companies. I will return to this later.

The Position Paper

In the introduction, the authors highlighted that the Task Force was formed because adaptive AI, a form of artificial intelligence, introduced a fundamental shift in clinical risk.

They grounded the position paper in three concepts: context of use (COU), the level of clinical risk involved, and the need for professional judgment by a licensed orthodontist.

They then emphasized that the central issue is how the presence of AI in orthodontics reshapes the orthodontist’s decision-making according to the function and degree of AI influence on patient care. To measure this influence, they divided the software into three types:

1. Clinical decision support software (CDS): provides information and recommendations without replacing professional judgement (cephalometric measurement);

2. Software as a medical device (SaMD): autonomously designs and delivers a device to be used clinically (bracket transfer tray);

3. Artificial intelligence/machine learning (AI/ML) software as a medical device in orthodontics: refers to SaMD that integrates ML capabilities (for example, a dental image analyzer used for remote treatment monitoring).

They then suggested six core principles to preserve professional authority, promote transparency in AI development, protect patient safety, and establish a principles-based framework:

Core Principle 1: AI governance and the human-in-command

Explains that AI governance is responsible for approving, validating, and monitoring AI systems to protect patient care. The human-in-command (HIC) concept puts the licensed orthodontist in charge of authorising and supervising AI use.

The call to action is that orthodontists must have the final word over all clinical decisions involving AI tools.

Core Principle 2: regulatory alignment and risk-based oversight

Explains that AI tools must follow regulatory requirements and require risk-based oversight according to the AI tool and its risk for harm.

The call to action asks that regulators, developers, and clinicians to jointly hold tool development and use to the highest international standards.

Core Principle 3: trustworthiness and transparency across the lifecycle

Explains that AI tools must be reliable, explainable, and consistent with transparency about how the models are trained, validated, updated, and monitored from the initial development through post-market use.

The call to action is directed to developers, who must build transparent, well-validated AI tools throughout their lifecycle; to regulatory bodies, to protect public trust; and to orthodontists, as the final decision-makers.

Core Principle 4: patient autonomy

This principle talks about how patients should be told by the orthodontist when AI tools are used in clinical decision-making. Patients should authorise the use of identifiable protected health information for AI development, validation, or retraining, when required.

The call to action is directed to clinicians to document AI use in patient records to clearly communicate so patients receive explanations of how AI supports their care and how their data may be used. State dental boards should also align their policies with national and international AI governance frameworks to protect patient rights and data privacy. Training programs should give clinicians the skills to use AI responsibly, explain it to patients in plain language, and keep data secure.

Core Principle 5: Education and Clinical Artificial Intelligence Competency

This principle recommends that orthodontists must receive education in AI throughout the profession to ensure AI strengthens professional judgement.

The call to action is to add AI coursework to dental school and residency training, provide continuing education courses (AAO), stimulate vendor-sponsored training programs, and help faculty build up their own AI knowledge so they can teach it.

Core Principle 6: Operational Integration and data privacy

This principle explains that safely working AI into a practice takes ongoing attention to safety, interoperability between systems, and protecting patient data at every stage.

The call to action is to use standardised data-exchange protocols, require compliance with HIPAA, the HITECH Act, and ISO/IEC security standards, vendors should be transparent about how they collect and use patient data, smaller practices need funding or technical help to keep up, and clinicians and staff need ongoing training in AI data ethics and cybersecurity.

Finally, they lay out a three-phase approach for evaluating and implementing AI tools: evaluate, implement, monitor, arguing that orthodontists should adopt new AI tools deliberately rather than ad hoc.

The authors highlighted some limitations, as the position paper does not establish legal responsibilities and only reflects the AAO’s current position.

They concluded that: 

• “The framework and core principles outlined in this document provide a roadmap for the safe, equitable, and effective adoption of AI in clinical orthodontics.”
• “Orthodontists remain accountable for technology selection and for the clinical use and oversight of AI tools at the point of care, including review of available validation evidence.”
• “Developers share responsibility for the ethical design, transparency, and secure deployment of AI tools.”
• “Data integrity and patient privacy must not be compromised.”
• “Continuous education is essential to sustain clinical readiness in a rapidly evolving digital landscape.”

The last paragraph started with a thoughtful and forward-looking phrase:

“The AAO envisions a future in which AI integration strengthens both the science and the art of orthodontics, advancing innovation while preserving humanity in care”.

What did I think?

As we have limited space, I will focus on some relevant aspects that I observed.

In my view, this position paper represents a useful guide for those interested in using AI responsibly. Still, I’d like to start with the task force composition. It was clear that they tried to form a diverse panel. However, three authors came from AI and digital companies (CADflow.ai, Dental Monitoring, and Align Technology) with a direct commercial interest. Even though all the authors declared no conflict-of-interest, I’d still flag it. The readers deserve to know.

Additionally, it would be nice if lay people had participated in the panel.

Going back to the position paper content, I considered that one of the most relevant aspects is the human-in-command approach, which places professional judgement at the centre of AI integration.

The position paper also made me think about a scale of AI use, ranging from limited AI use with substantial human participation in the decision-making process to extensive AI use with limited human participation. This is referred to as the AI context of use (COU), and it can help define the risks for patients receiving treatment: for now, the less human participation there is, the greater the potential risk to the patient, though that balance could shift as AI becomes more assertive. Thus, patients should be informed about the extent to which AI is being used in their care.

Another relevant contribution of this position paper is helping to understand AI adoption as a shared responsibility among clinicians, developers, regulators, and educators.

Lastly, I strongly agree that AI literacy must be included in the education of new professionals and in faculty development to ensure that patients are treated ethically and can benefit from advances in AI.

Final thoughts

Although this position paper is extremely relevant, it is also extensive, and I am concerned that this information may not reach the orthodontic community, developers, regulators, and educators worldwide.

This is because some regulations are specific to the USA and may not apply to other countries. Nevertheless, I believe that most of the content presented can be useful and applicable in other nations. It would be valuable if other associations developed position papers with a broader, worldwide perspective on AI.

For orthodontists, the key message is clear: understanding AI is no longer optional, but its use must remain transparent, accountable, and focused on patient safety.

With the presence of AI, it is likely that we are entering a new era called augmented orthodontics, in which orthodontists can offer patients a better healthcare experience.

Disclosure: I used AI tools to help verify this summary against the original paper and to polish the writing. The analysis and opinions are my own.

       

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I have discussed two studies that have been produced by the Lightforce company and pointed out that these were significantly flawed. It is therefore good to see an independent study,Which is a retrospective evaluation of cases. The results provide us with further information on this new technology. 

A team from Connecticut, USA, carried out this research. The Anglo orthodontist published the paper. 

Treatment outcomes, efficiency and complications of customized ceramic brackets compared with conventional fixed orthodontic appliances

Hormozi et al

Angle Orthodontist. DOI: 10.2319/030326-188.1

What did they ask?

They did this study too. 

“Examine the treatment outcomes and complications between customised ceramic brackets and conventional fixed appliances to determine whether the proposed advantages of customised systems result in measurable improvements in clinical performance and efficiency.” 

What did they do? 

They conducted a retrospective cohort study of orthodontic records from a multi-doctor, single-practice office in Connecticut, United States. 

This practice has used LightForce brackets since 2019. 

The team screened all the records of patients who completed comprehensive treatment between 2019 and 2025 on a non-extraction basis. Of these, 75 met the inclusion criteria. Thirty-six were treated with light force, and 39 with fixed appliances. 

The main inclusion criteria were that patients were 12 to 30 years old at the start of treatment, had fully erupted permanent dentition, and had complete pre- and post-treatment records. 

Four ABO-certified orthodontists with more than 14 years of experience treated all the patients. They gave the patients standardised verbal and written instructions, and there was no difference between the two systems in these instructions. Importantly, the archway sequences were based on treatment progress. 

They saw the patients every 4 to 5 weeks. 

The primary outcome measure was the ABO-OGS score at the End of treatment. Secondary outcomes were:

• the bracket failure
• emergency visits
• total scheduled visits
• overall treatment duration

What did they find? 

Thirty-six patients were treated with LightForce, and 39 were treated with conventional brackets. The groups did not differ in sex distribution, skeletal malocclusion, or ABO-DI scores. 

I have included the outcome-measure data in this table. 

I have calculated the differences in means and 95% confidence intervals using their data.  One important feature to note is that the 95% CIs are wide and this signifies that there is uncertainty in the data. This is likely to be due to the relatively small sample sizes.

The authors wrote a nice discussion on this data. They noted that the end of treatment ABO-OGS scores were similar between the groups, and that the 3-point difference was marginally significant. They also noted that the LightForce group had a shorter treatment duration of about 4 months, with fewer scheduled visits. However, they also pointed out that bracket-related complications were more frequent in the LightForce group, with more broken brackets and more emergency visits for bracket failure. 

Their final conclusions were: 

“LightForce achieved overall treatment quality comparable to conventional fixed appliances, but with an improved treatment efficiency. However, they were associated with a higher rate of bracket-related complications.” 

What did I think? 

The study offers a useful advance in research on customised brackets. I have noted that other preliminary publications have been significantly flawed. As a result, it is good to see that this paper provides us with more robust information. 

The results are clinically interesting. Importantly, the authors showed no real difference in the quality of finish. The most relevant finding was that LightForce required a shorter treatment time and fewer scheduled visits. However, LightForce had more bracket failures, so the differences in the number of visits were reduced. As a result, this study reflects the effectiveness of LightForce, which is influenced by “swings and roundabouts”. 

The authors highlighted several deficiencies in the study design. These included the study’s retrospective nature and, importantly, a lack of information on the patient-selection method and how many patient records were searched. It also struck me that the sample size was rather low, given the almost 6-year data collection period. This suggests there may be considerable selection bias in this study. 

Nevertheless, as I said before, this is a step in the right direction, and it would be great to see some randomised trials in this area. At the moment, these new developments do not seem to offer many clinically significant advantages. 

       

Comments

• Light Force does not have auxiliary tubes or allow for bands to ... by BT
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• How much orthodontic harm could we avoid?

 

Most orthodontists are probably familiar with the results. However, I have reviewed them in light of our knowledge of how to conduct trials, which has expanded rapidly over the past 20 years. 

A team based in North Carolina, USA, conducted the trial. The American Journal of Orthodontics published the paper. 

Outcomes In a two-phase randomised clinical trial of early class II treatment 

Tulloch, Philips and Proffit.

AJO-DDO. doi:10.1016/j.ajodo.2004.02.008

I would like to declare an interest, as I provided input on using the PAR index as an outcome measure. I also knew the authors very well.

This group published several papers on the results of this trial. In this paper, they condense most of the results. 

What did they ask? 

However, at the start of this study in 1990, there was controversy over treatment timing for early Class II malocclusion.

1. That early Class II malocclusion could be intercepted with a course of orthodontic treatment in Phase I, followed by a comprehensive course of treatment in Phase II during adolescence.

2. That treatment should be deferred until the dentition was established, with a single course provided during adolescence.

As a result, they did this study to.

“Find out whether treatment started in the mixed dentition before adolescence, followed by a second phase of treatment in the early permanent dentition during adolescence, provides superior results to a single-phase treatment delayed until adolescence.” 

What did they do? 

They conducted a randomised trial with a 1:1:1 allocation of interventions. The PICO was 

Participants 

Children with an overjet of 7 mm or more in the mixed dentition, at least a year before their peak pubertal growth 

Intervention 1 

A Bionator appliance worn full-time. 

Intervention 2 

Cervical pull headgear.

Intervention 3. 

An untreated control group that was observed for 15 months. 

Outcomes 

The primary outcomes were selected cephalometric measurements. Secondary outcomes were Peer Assessment Rating (PAR) scores, complexity of treatment, and total treatment time. 

During the first phase of treatment, they randomly allocated patients to the three interventions. They concealed the allocation by using a pre-prepared randomisation, which was emailed to a research assistant, who informed the clinician. At the end of this phase of treatment, patients were re-randomised, again using standard randomisation techniques, to one of four orthodontists who completed their definitive treatment. 

They carried out the relevant univariate and multivariate statistical analyses. 

What did they find? 

170 participants started the trial, and 166 completed phase I treatment. After a waiting period, 145 returned for phase II treatment. Of these, 139 completed phase II. At the final point, they analysed data for 137 participants. 

At the end of phase I, they found modest skeletal changes. However, during phase II, the differences between the groups were lost. At the end of fixed appliance treatment, there were no significant differences among the three groups for any cephalometric measurements.  For example, the final ANB values were 4.3 (2.06) for the control, 3.79 (2.12) for the early functional and 4.0 (1.9) for the early headgear groups.

For occlusion, there were no differences in Peer Assessment Rating scores at the end of phase II. For the control group the mean PAR score was 9.3 points, for the early functional this was 8.8 and for the headgear group this was (7.2)

There were also no meaningful differences in the overall treatment time or the percentage of children who had teeth extracted as part of phase II treatment. 

The overall conclusion was 

“Early treatment should not be thought of as an efficient way to treat most Class II children.” 

Importantly, they pointed out that the trial illustrated the risk of relying on clinical impressions. This was because, early in the trial, they were very impressed with the progress of the children receiving early treatment and even considered stopping the trial then. 

What did I think? 

This is a classic paper outlining a very ambitious study for its time. It was well written, clear, and succinct in the usual style of the authors. I thought it was notable that the authors spent some time outlining the rationale for conducting a randomised controlled trial. This reflected a time when trial methodology was relatively new to orthodontics. 

As with all papers written by the UNC group, there were some great quotes. I was particularly struck by this one, originally made by David Sackett. 

“Enthusiastic treatment reports tend to have no controls, whereas well-controlled treatment reports tend to have no enthusiasm” 

We would do well to remember these words now, as we are suffering an onslaught of poor-quality studies and case reports promoting orthodontic fringe treatments.

Final thoughts. 

This paper was a valuable addition to our knowledge and set the scene for further, more complex trials that I and others could carry out.

We need to consider whether it withstands contemporary scrutiny. I think it is important to note that when this paper was included in Cochrane reviews, it was classified as having a high risk of bias. This was largely because the allocation concealment was not clearly reported, but more importantly, the cephalograms were digitised in a non-blinded manner because the headgear bands were left in place. As a result, the technician knew the treatment allocation. This does not mean the study is biased. It means the study is at high risk of bias. 

This is also similar to many studies carried out at the time and reflects the methodology we used and possible reporting deficiencies, as the CONSORT guidelines had not yet been produced.

Nevertheless, we need to consider the findings in light of these issues. I have thought about this very carefully. I still feel that this is a great piece of research that changed orthodontic practice. As a result, the findings are relevant. 

Finally, I feel that those who promote early treatment, expansion, or orthodontic-driven treatment for paediatric sleep disorders should revisit this paper. They will learn a lot about complex orthodontic research and how to interpret it. We must not forget our classic research as we attempt to move forward.   

       

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• A simple and clear paper on orthodontic retention.

 

Simon Littlewood, who is an authority on retention, based in Bradford, Yorkshire wrote this paper. The American Journal of Orthodontics published his paper.

Post-treatment orthodontic care for retention and stability

Simon Littlewood

AJO-DDO. https://doi.org/10.1016/j.ajodo.2026.01.025

This paper is not open access, so reading the full text is not easy. This is a shame, and I wonder whether the AJO-DDO could make this paper freely available so that this knowledge can be shared?

I would like to declare an interest, as I know Simon Littlewood well. 

His aim in writing this paper was to

“Outline the current status of orthodontic retention, based on the results of clinical research, clinical experience, and patients’ perceptions”. 

There is a large amount of useful information in this paper. It is difficult for me to summarise it all, but I will do my best to outline the main points.

The inevitability of relapse 

We are all familiar with the University of Washington publications from the 1970s. These show that relapse is unpredictable and that it is not possible to predict which patients will remain stable. We also know that relapse may be related to post-retention factors such as facial growth and natural ageing. As a result, we should remember that relapse is inevitable. Nevertheless, we should take steps to retain our final treatment occlusion as far as we can. 

Clinical expertise 

To consider evidence-based retention, we must immediately consider the role of clinical expertise. Although there have been many studies on methods of orthodontic retention, it is clear that the results of these studies are influenced by the operator’s skill and experience. This is similar to most areas of orthodontic treatment. 

Patient values. 

Patients need to consider the effects of their attitudes, expectations, and willingness to undertake certain forms of treatment. This is perhaps the most important factor when we consider retention, as we know our patients need to develop a long-term commitment to reduce unwanted change. 

Importantly, he points out that patients are more likely to wear their retainers if they establish a good pattern of retention wear immediately after the end of their treatment. Furthermore, they report that they wear their retainers because they don’t want to disappoint their clinician, and it is always important for them to have a spare set of retainers in case they are lost. 

Research evidence 

In this section, he draws heavily on the recent Cochrane review, which includes data from 47 randomised trials. Unfortunately, he points out that the evidence on retention remains relatively low, making it difficult to recommend a particular approach at present. There is a clear need for longer-term studies. He uses some of the evidence from this review in the later sections of his publication. 

Types of retainers Fixed retainers 

Most of us have used fixed retainers for our patients. This is because they offer the clear advantage of not requiring compliance to wear them. There is little effect on retention between the different types of wire retainer that can be used. Recently, there have also been developments in CAD/CAM technology. However, there is little evidence to support their increased effectiveness with this new technology. Nevertheless, this may offer clinicians a better and more efficient workflow. 

When we consider the failure rate of bonded retainers. This is surprisingly high, at approximately 35%. Other disadvantages include the potential to increase the risk of plaque and calculus buildup, which may lead to long-term periodontal problems, although long-term studies are lacking. 

The final potentially serious problem with bonded retainers is wire syndrome, in which unwanted bends in the wire cause excessive tooth movement, leading to severe periodontal defects and tooth loss. In this respect, it is essential to regularly review retainers. 

Removable retainers 

In this section of the paper, he outlines the differences in effectiveness between Hawley and clear plastic retainers. Additionally, he points out that high-quality research shows that clear plastic retainers can offer some advantages over Hawley retainers. Moreover, importantly, patients tend to prefer clear retainers because of their better aesthetics. Furthermore, the results of RCTs also show that removable retainers are normally worn at night. They do not need to be worn full time.

When we consider the potential harmful effects of plastic retainers, there are recent concerns about microplastic leaching from these. However, the research is in its early stages, and we urgently need further research in this area. 

Nevertheless, we do need to bear this theoretical problem in mind when discussing retainers with our patients. 

The choice or removable or fixed retainers 

I think one of the major issues in retention is the choice between fixed and removable retainers. I went through several phases, preferring different types of retainers throughout my career, and eventually leaned towards clear removable retainers in my last few years of clinical practice. 

Simon points out that most evidence shows that within the first 6 to 18 months, there’s little difference in the effectiveness of fixed and removable retainers. There are, of course, several advantages and disadvantages of each of these methods, and he has provided this information in a clear table within the article. This provides a useful source of information for discussions with our patients. 

Shared decision making 

The final section of this paper addressed shared decision-making with our patients. Importantly, he points out that shared decision-making means taking treatment decisions with our patients rather than about them, and this has been shown to increase cooperation with treatment regimes. 

This means it is very important for us to discuss the advantages and disadvantages of the different types of retainer with our patients. This also brings me to retention review. It is clear that there is a need for long-term review of any form of retention, and the responsibility is shared among the orthodontist, the patient, and the general dentist.

In this respect, it is not acceptable to discharge patients and inform them that their general practitioner will look after the retainer. A more reasonable approach is to ensure that the general dentist understands the importance of retention, knows how to monitor retainers, and can make repairs. As a result, it is important that knowledge and skills related to monitoring retention should be included in undergraduate and Continuing Professional Development Courses. I cannot help thinking that this is easier said than done and may be the weak link in providing orthodontic retention. 

His overall conclusion was 

“Absolute stability after orthodontic treatment is not feasible, but it is possible to reduce unwanted post-treatment changes with appropriate use of retainers”. 

He has outlined this nicely in this paper. 

What did I think? 

It is unusual for me to review a summary paper. However, I thought this one was so useful that it was worth sharing more of the knowledge it contains. 

If we consider that the three components of evidence-based care are clinical experience, research evidence, and patient perceptions, then Simon has covered these very well in this publication.

Importantly, he has relied heavily on research evidence, much of which comes from randomised trials. He combines this very well with clinical experience and a substantial body of research on patients’ perceptions.

As a result, I feel this is an excellent publication, and we should all consider its conclusions when providing retention care for our patients. 

       

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I have previously posted about the first part of the study.

Patient Harm From Orthodontic Care (Part II): Incident Analysis of Contributory Factors and Perceived Avoidability of Harm

Nikolaos Ferlias, Athanasia Grigoroudi, Julian Woolley, Sukeshana Srivastav, Henrik P. Nielsen and Peter Stoustrup

Orthodontics & Craniofacial Research, 2026

https://doi.org/10.1111/ocr.70172

I have previously posted about the first part of the study.

What did they ask?

They did this study to:

1. Identify the factors contributing to patient harm;
2. Estimate whether the harm was avoidable;
3. Explore the relationship between avoidability and the number and type of contributory factors; and
4. Suggest ways of reducing future incidents.

What did they do?

The authors examined 125 orthodontic claims approved for compensation by the Danish Dental Compensation Association from September 2019 to August 2024. They aimed to identify the factors contributing to harm and estimate how much of it might have been avoided.

An experienced orthodontist reviewed the clinical records, radiographs, photographs, correspondence and compensation decisions for each claim.

The reviewer classified possible contributory factors using the Eindhoven Classification Model. These included:

• human factors, such as monitoring, verification and clinical knowledge;
• organisational factors, such as protocols, management priorities and workplace culture;
• technical factors involving appliances or materials; and
• patient-related factors.

The same reviewer then rated the avoidability of each incident on a six-point scale, from completely unavoidable to completely avoidable.

Finally, the authors grouped the cases into low-, moderate- and high-avoidability categories. They used ChatGPT to help develop qualitative descriptions of the patterns and possible mitigation strategies. The authors state that the AI did not review patient records, identify contributory factors, or determine whether harm was avoidable.

What did they find?

The most common categories of compensated harm were:

• Gingival or other soft-tissue harm: 17%;
• Apical root resorption leading to tooth loss: 15%;
• Worsening of the occlusion following treatment: 11%;
• Cervical root resorption leading to tooth loss: 10%; and
• Damage to a tooth crown: 7%.

Just over half of the harm-causing events occurred during active orthodontic treatment. Delayed diagnosis accounted for 22%, while retention-related incidents accounted for 10%.

The authors identified a median of five contributory factors per case. Monitoring and verification problems were the most common, occurring in 56% and 54% of cases, respectively. They recorded deficiencies in clinical knowledge and professional qualifications in approximately 42%.

Organisational factors were also common. These included management priorities, workplace culture, inadequate protocols, and ineffective knowledge transfer between team members.

Patient-related factors were identified in 45% of the compensated cases. This does not necessarily mean that patients “caused” the harm. It indicates that factors such as biological variation or cooperation may have formed part of a more complicated chain of events.

Finally, they concluded that 82 incidents were probably, highly or completely avoidable. They reported this as 70.1% of the claims assessed for avoidability.

Cases considered highly avoidable tended to contain more contributory factors. In other words, serious, avoidable harm often appeared to stem from several failures interacting rather than from a single isolated mistake. This is similar to other “never” events that arise from a series of unfortunate events. 

Their conclusions were

“70% of the compensated cases were avoidable and most harms were mutltifactorial in nature.”

What did I think?

This is an important paper because patient safety receives surprisingly little attention in orthodontic research. We devote considerable effort to comparing appliances and measuring small differences in treatment efficiency. Avoiding tooth loss, periodontal damage or a missed diagnosis is likely to be far more important to patients.

The use of a national, no-fault compensation scheme is also a strength. Patients did not need to establish malpractice before applying, which may reduce some barriers found in litigation-based datasets. The investigators reviewed detailed clinical material rather than relying only on brief incident reports.

The central message is both plausible and useful. Harm often develops when monitoring, verification, communication and clinical systems fail together. Simply identifying and blaming the last clinician in the chain is unlikely to prevent the next incident.

Limitations

As with all studies, there are some limitations that influence our certainty about the findings.

Most importantly, these 125 cases were not a random sample of orthodontic treatment. They were approved compensation claims. They are consequently likely to represent unusually severe or readily identifiable harm. We cannot use this study to estimate the risk of being harmed during orthodontic treatment, nor can we conclude that 70% of all orthodontic complications are avoidable.

Additionally, only one investigator performed both the incident analysis and the avoidability assessment. Even though this was an experienced reviewer using a structured system, this is still a structured judgement. The authors did not test agreement with a second assessor or repeat the ratings to assess the reliability of the ratings.

Finally, I was not sure whether the AI-generated interpretations and recommendations were helpful. The important work was the human review and classification of the cases. Suggestions generated from those classifications remain suggestions; the study did not test whether checklists, protocols or additional training actually reduce orthodontic harm.

What can we learn from this paper?

I took from this paper that we should:

• monitor treatment actively;
• verify diagnoses, treatment decisions and critical procedures;
• arrange appropriate radiographic review when there is a risk of root resorption or damage associated with impacted teeth;
• establish clear routes for communication and referral;
• document the reasons for important decisions;
• use significant incidents as opportunities for team learning; and
• develop systems that make safe actions easier and unsafe omissions more difficult.

This may be obvious to many readers of my blog. But patient safety requires competent clinicians working within practices that support communication, verification, reflection and timely action.

Final thoughts

This was an interesting and worthwhile study of a neglected area.

The findings suggest that, among a selected group of compensated incidents, many harms were considered avoidable and usually involved several unfortunate events.

I think the 70% estimate is only a rough estimate. However, the wider conclusion is convincing: monitoring, verification and good clinical systems are important.

       

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This new study looked at the effectiveness of corticotomy-assisted RME and protection in late adolescence.  

A team from Turkey did the study. The American Journal of Orthodontics published the paper. 

Corticotomy-assisted rapid maxillary expansion and maxillary protraction therapy in late adolescence: Evaluation of 3-dimensional stereophotogrammetric soft-tissue, cephalometric, and 2-dimensional airway changes: A prospective controlled clinical trial

Coban et al. 

AJO-DDO https://doi.org/10.1016/j.ajodo.2026.05.014

What did they ask?

This study was conducted to find out protraction.

“The short-term effects of corticotomy-assisted RME and face mask therapy in late adolescent patients with skeletal Class 3 malocclusion compared with no treatment” 

What did they do? 

They did a prospective single-centre, non-randomised, controlled clinical study. 

The sample in this study was formed of orthodontic patients aged 13 to 16 years with a true skeletal Class 3 malocclusion with maxillary deficiency and an anterior crossbite. The investigators allocated them to two groups:

16 patients received corticotomy-assisted rapid maxillary expansion followed by face mask treatment.

16 received no treatment during a comparable observation period.

The patients underwent bilateral maxillary corticotomies under general anaesthesia. The surgeons raised mucoperiosteal flaps and made cortical cuts extending from the piriform aperture towards the pterygomaxillary region.

After expansion, the patients wore a facemask for 14–18 hours per day, applying 750–1000 g of force on each side. Treatment continued until they achieved a Class I occlusion and a positive overjet. The mean treatment duration was approximately 8 months.

Outcomes

The investigators collected lateral cephalograms and 3D facial photographs before and immediately after treatment. Their primary outcome was the position of Point A relative to the nasion perpendicular. They also measured numerous skeletal, dental, airway and facial soft-tissue variables.

Importantly, they sought to address the large number of statistical comparisons by applying a false-discovery-rate correction to the secondary outcomes. They also performed adjusted analyses that accounted for baseline measurements, age, sex, treatment duration, and skeletal maturity.

What did they find?

They presented an incredible amount of data on the cephalometric airway and facial scan changes. This created a wall of confusing “white noise”.  I have never seen so much data in a single paper.

I do not have the space to go into most of these here; however, they reported that the  principal changes in the treated patients compared with the control group were  

• 2.35 mm greater forward change at Point A;
• 4° improvement in ANB;
• 6 mm improvement in overjet;
• 3.4° increase in the mandibular-plane angle;
• 4.3° retroclination of the lower incisors; and
• 3.3 mm relative posterior change in pogonion on the cephalometric measurement.

The 3D facial analysis showed changes consistent with increased facial convexity and forward movement around the base of the nose. Nasal alar width increased by 1.57 mm and alar-base width by 1.97 mm.

There were no clinically or statistically significant differences in the airway between the groups. However, this was measured from the cephalograams, so I doubt that this data was useful.

Their final conclusion was

“Despite reduced growth potential, corticotomy-assisted RME and face mask therapy produce short-term skeletal and soft tissue improvements in patients with true skeletal Class 3 malocclusion. However, long-term stability and randomised comparative data are required.” 

What did I think?

This was an interesting paper that gave us some important, clinically relevant information on treatment effects, which are logical.

The study was well done, and I have no doubt that it was difficult to carry out. They reported many outcomes, which led to the inclusion of numerous cephalometric and other tables. As a result, I found it impossible to assess all the variables. This paper would certainly have benefited from a more focused analysis.

However, we need to consider carefully whether the nature of the study influences our interpretation of the results. In this respect, I feel there are many reasons for us to be cautious. Importantly, the authors have highlighted nine shortcomings in their study. This is possibly the largest number of shortcomings that I have seen authors acknowledge in a paper in the American Journal of Orthodontics.

I feel that there are several major areas of concern. Firstly, this was not a randomised trial. The control group was self-selecting, as they declined treatment because of school or family obligations. This means that the study has considerable selection bias. This is because patients willing to undergo this rather invasive treatment may differ from those who decline it. While I do agree that the statistical analysis this team used may correct some of the unknown measurable differences, this is also unlikely given the small sample size. 

I was also confused, as it appeared that the cephalometric and scan data were not blinded. Therefore, we cannot exclude examiner bias in this study. 

My last major concern was that poor cooperation was an exclusion criterion. This was identified by parent reports, the absence of signs of wear on the appliances, and, most importantly, a lack of change in overjet during the first three or four months. This means that the sample analysed may have been biased towards those who respond well, which could exaggerate the apparent effectiveness of the treatment.  I could not find any information on the number of patients who were excluded because of poor co-operation.

Final comment. 

We need to bear in mind these methodological deficiencies when we consider these findings. There is no doubt that the clinical changes are interesting and large enough to be clinically valuable. However, the problems with selection bias, proficiency bias, and data bias are substantial. As a result, we should be very cautious in interpreting these findings for our clinical treatment. There is certainly a need for randomised trials in this very interesting area. 

       

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Introduction

This is a really interesting paper produced by a well-established international team of researchers based in Dublin, Bern and Riyadh, investigating an issue of fundamental importance to the practice of evidence-based orthodontics. The novelty, importance and quality of this study are reflected in its publication in the Journal of Dental Research, a high-impact journal that is very difficult to publish in.

Predatory journals

Predatory academic journals are a product of the online publishing industry and purport to be legitimate, adhering to high standards of publishing ethics and facilitating rapid open-access publication, but often they do not. Many of these journals aggressively solicit submissions, charge high publication fees, and rely on high-volume, rapid publication output for their financial model. For these reasons, the peer review and editorial processes are often less than robust, leading to the publication of papers of low methodological quality.

Predatory Publications Bias the Findings of Orthodontic Meta-analyses

M P Maroulakos, Z Tatas D Al-Moghrabi, N Pandis, P S Fleming

Journal of Dental Research

DOI: 10.1177/00220345261466209

What did they ask?

They did this study to ask;

“What is the prevalence of predatory papers included in meta-analyses of orthodontic systematic reviews and to describe the prevalence and the characteristics of recent systematic reviews published in legitimate, suspect, or predatory journals within the field of orthodontics”.

What did they do?

This study has investigated the influence of predatory publishing in orthodontics, focusing specifically on orthodontic systematic reviews, which represent a fundamental component of evidence-based practice. The authors searched various databases for English-language orthodontic systematic reviews published between 2020 and 2023, and then analysed these reviews for a number of parameters, including their general characteristics (type, topic, authors), the type of journal in which they were published, and, importantly, whether the journal was regarded as legitimate, suspect, or predatory.

They further investigated one meta-analysis from each of these systematic reviews and extracted data on the primary studies included in each (again, assessing whether any had been published in predatory or suspect journals). Specifically, any meta-analyses containing at least one study published in a suspect or predatory journal underwent a further subset analysis (effect measure, sample size, heterogeneity), including analyses of the data using either all studies or only those published in legitimate journals.

What did they find?

There were some really interesting findings, albeit slightly depressing. They identified 340 eligible systematic reviews, and among these, 114 (33%) contained primary data from at least one predatory or suspect journal. The majority of these systematic reviews (60%) were published in broader-scope medical and general science journals, not orthodontic – and 16% of these journals were classified as predatory or suspect. Among the 114 systematic reviews that had their primary meta-analyses re-analysed, the median sample size within the included studies was only n=20, with a median I2 score of 85% (demonstrating that studies with small sample sizes and substantial heterogeneity often populate these meta-analyses). Recalculation using all included studies, or only those published in legitimate journals, resulted in pooled estimates decreasing in 55% of meta-analyses and increasing in 45%.

What did I think?

The importance of this study is that it provides data supporting the perception many of us who spend time reading these systematic reviews have held for years – that they often include primary studies of questionable validity and probably should not have been published. Perhaps most surprising is the sheer scale of data that is out there, emanating from predatory or suspect journals. One in three orthodontic meta-analyses contains primary data from these journals, and almost one in six orthodontic systematic reviews. The effect of data derived from predatory publishing on pooled estimates in meta-analyses is unpredictable and therefore adds considerable uncertainty to the evidence.

The harsh reality is that the current orthodontic evidence base, derived from systematic reviews, is likely to be significantly distorted by predatory publishing practices, with over- and under-estimation of treatment effects commonplace. There are too many journals, too many systematic reviews, and too many unreliable studies. Read them and interpret them with caution…………………..

       

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