The study team tested a modified open exposure technique that they have used for over 40 years (GOPEX). This involved, instead of surgical packing, applying glass ionomer cement to the canine. The glass ionomer remains on the tooth until it has spontaneously erupted above the gingiva. This certainly seems to be a better method than the one I used when I practised, where we placed a periodontal dressing over the open exposure and removed it after 10 days. Unfortunately, it tended to detach, and the tooth happily covered up again.

The well-known trial team from Gothenburg, Sweden, conducted this study. The European Journal of Orthodontics published the paper. Since it is open access, anyone can read it. 

Glass ionomer open exposure and closed exposure of palatally displaced canines: a randomised controlled trial comparing postoperative pain perception and complications

Anna Dahlén et al

EJO Advance access: https://doi.org/10.1093/ejo/cjag011

What did they ask? 

They did this study too.

“Compare glass ionomer open exposure (GOPEX) with closed exposure (CE) in terms of patient-reported outcomes, surgical duration, and complications.” 

What did they do? 

They did a single-centre randomised controlled trial with a one-to-one allocation of two parallel groups. The PICO was:

Participants 

Children and adolescents under 18 years old with a palatally displaced canine were referred for treatment between March 2017 and April 2024. The main inclusion criteria were that they had a unilateral PDC and were planned for surgical exposure and orthodontic treatment. Importantly, the canine had to be positioned within sectors 2-5 on the panoramic radiograph. 

Intervention one. 

GOPEX. This was an open exposure in which glass ionomer cement was applied to the cusp tip of the exposed PDC. 

Intervention two. 

The paediatric dentist exposed the tooth, and then bonded an eyelet and chain with light-cured composite. They then sutured the flap back to its original position. 

Outcomes 

The study reported on several outcomes. The primary outcome was the amount of pain recorded by the patients. They also included information on the children’s fear of their procedure, as well as the duration of surgery and any complications. 

They used a pre-prepared randomisation scheme. Allocation concealment was stored securely at the clinic and was not accessible to the recruiting orthodontists. The allocation was carried out after obtaining the patients’ written consent. 

One of three experienced paediatric dentists performed the surgical procedures. 

They did a clear sample size calculation. Based on the amount of pain the patients could report. This revealed that 40 patients per group were required. They increased the target sample to 92 participants to compensate for dropouts. 

They conducted relevant multivariate and univariate statistical tests, and clearly outlined them in their paper. 

What did they find? 

They randomised 92 patients to the interventions: 43 to the GOPEX group and 40 to the closed exposure group. All of these patients completed the study.

During the first fourteen post-operative days, there were no significant differences between the groups in pain levels; however, after seven days of cooperation, pain scores were substantially higher in the GOPEX group than in the CE group. There were no differences in the percentage of pain-free patients, analgesic use, or chewing difficulty. 

Their overall conclusions were: 

“The GOPEX group had more pain in the first post-operative week, but no difference was seen in pain scores or any other outcome measures over the whole 14-day post-operative period.” 

What did I think? 

This was a very well-executed and well-presented trial and publication. They followed the CONSORT guidelines in their write-up; all aspects of a good trial were achieved. This is a high-quality research paper. 

When I reviewed their results, I found them to be clinically useful. Importantly, they found no difference between the two interventions in any of the outcomes they assessed. This provides us with valuable information we can share with our patients when they choose their preferred treatment.

However, while this information is useful, I could not find any details in this paper about the relative success rates of the two interventions. I contacted the authors to ask when this information will be available. They told me they are writing a paper on this and hope to publish it in early 2027. Once they have published this research, we will have the information needed to make clinical decisions with our patients. 

    

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A team from Mansoura, Egypt conducted this research. The angle orthodontist published the paper. 

Dento-facial changes and oral health-related quality of life assessment in management of anterior crossbite in mixed dentition: a randomized clinical trial.

Asmaa S. Salem et al

Angle Orthodontist On line advance access. DOI: 10.2319/020325-109.1

What did they ask?

The authors did this study to

“Evaluate the dental-facial changes and the improvement in oral health-related quality of life between clear aligners and inclined plane appliances for managing anterior functional crossbite in the mixed dentition.” 

What did they do? 

They conducted a single-centre, randomised clinical trial with a parallel design, allocating participants in a 1:1 ratio. The PICO was: 

Participants 

24 children aged 8 to 12 years who had an anterior functional crossbite involving more than two teeth 

Intervention one. 

In-house clear aligners. They asked the patients to wear their aligners for 22 hours a day and change the aligner every 10 days. 

Intervention 2. 

A removable inclined plane which fitted the lower arch. This was made of transparent sulfur-cured acrylic resin, which was applied to a PETG sheet. The operator saw the patients every two weeks, and the operator relieved the inclined plane. After the completed treatment, they asked the patients to wear their appliance for a further four weeks. 

Outcomes 

The primary outcomes were cephalometric measurements; however, they based their standard sample size calculation on the upper incisor to SN angle, and I’ve assumed that this is the primary outcome. Secondary outcomes were oral health-related quality of life, and they measured this using the CPQ 8-10 questionnaire. 

The team performed a clear sample size calculation that suggested they needed 12 patients per group. 

The same postgraduate student treated all the patients at a single centre.

They used a pre-prepared randomisation sequence, and the allocation was performed by drawing a card from a box containing 24 cards, with 12 cards assigned to each group. It was not possible to treat the patients blindly; however, all data was analysed blind. 

They analysed the data using univariate statistics to evaluate any differences between the groups. 

What did they find? 

24 of the patients completed the trial. I could not find any information about whether they corrected all the crossbites, but I assume that this was the case. 

At the start of treatment, there were no differences between the two groups. 

They then supplied a large amount of cephalometric data with multiple comparisons. As you know, I find this kind of data presentation rather confusing and unclear. This is especially due to the risk of false positives when measuring many related variables and performing simple statistical tests. 

As a result, I have just concentrated on the straightforward outcomes of upper incisor and lower incisor angulation.

When they looked at U1-SN. In the clear aligner group, after treatment, the upper incisor position was 114.44mm (6.03).  Whereas for the inclined plane appliance, this was 108.1 mm (4.31). The mean change in this measurement was 11.65mm (3.95) for the clear aligner and 6.73mm (2.94) for the inclined plane group.  This difference was statistically significant.

When they evaluated the L1-NB (mm). For the clear aligner group, the mean was 4.01mm (1.73), and for the inclined plane group, it was 3.93mm (2.34). When they evaluated the change in this measurement, this was 0.77mm (1.42) for the clear aligner and -2.03mm (2.21) for the inclined plane group. This was statistically significant.

Finally, there were no differences in the oral health-related quality of life measurement between the groups; however, both groups showed an increase in this measurement, indicating an improvement in oral health-related quality of life for all participants.

The final conclusions were;

“The clear aligner group experienced more proclination of the upper incisors, whereas the inclined plane group showed that upper incisor proclination and lower incisor retrusion resulted in the correction of the anterior crossbite”.

What did I think?

Firstly, I thought it was positive to see more studies exploring the effectiveness of clear aligners. Importantly, this study demonstrated that clear aligners are an effective treatment for anterior cross-bite with a functional shift. However, it was also notable that there were no significant differences in the final treatment outcomes between the clear aligners and the simpler inclined plane appliance. This finding is important because, as the authors suggested, the inclined plane appliance offers a cheaper alternative to using clear aligners. 

When I examined the design of the two interventions before reading this paper, I expected to see different cooperation rates, as the inclined plane seems to be a much more challenging device for participants to tolerate. It was interesting that this was not the case, as there were no significant differences in cooperation rates between participants in either group.

In summary, this was another well-conducted small study on the effectiveness of clear aligners. This leads us to the conclusion that this study provides important information that may guide our patients’ decisions when they are giving consent for treatment.

    

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This post is rather long, but I want to cover a lot of information. I will not be posting much about this subject in the next few months, unless a useful research paper is published.

Introduction

First, I would like to examine the definition of a white paper. This varies between countries. The definition for the USA is:

“An authoritative, in-depth report that analyses a specific health issue to educate stakeholders, propose solutions, or influence decision making. They are positioned between peer-reviewed research and marketing.”

Importantly, it is not a high-level research paper or systematic review. It is worth noting that the authors do not adhere to systematic review methodology.

Therefore, we should remember that a white paper presents a series of conclusions based on our best available research. It is important to recognise that these are recommendations, not mandatory requirements, and are therefore not compulsory. Nonetheless, this paper offers guidance for the future, as it contains solid clinical advice. 

Is this important?

I also wonder how significant an issue sleep-disordered breathing and orthodontics are worldwide. As with many aspects of orthodontics, the push for “new” treatments and changes seems to originate from the USA. This is probably due to the greater number of orthodontists in the USA compared to other parts of the world.

I am also aware that some of the most vocal social media outputs and groups are USA-based. Subjectively, when I have seen comments from other countries, they tend to be more conservative, traditional, and possibly more grounded in science.

Therefore, we must keep in mind that the content and focus of this white paper are likely more relevant to the United States than to other parts of the world. Certainly, when I consider the UK, there doesn’t seem to be a strong drive to implement airway-focused orthodontics, apart from a few of the “usual suspects” who adhere to the mantra of orthotropics and other fringe treatments.

As a result, we need to be careful not to become dominated by USA-based orthodontics, as there is a risk of wasting a considerable amount of time.

In this context, I have decided to review this white paper. 

The panel

It is evident from the information on the panel members that this is a carefully assembled group of experts. The panel comprises a mix of practitioners, representatives of the AAO, and research academics.

The Introduction

This was well written and clear. I was particularly impressed by the way they described the somewhat confusing situation of sleep-disordered breathing (SDB), its medical and surgical treatments, and the role of orthodontics. Importantly, they pointed out that sleep-disordered breathing is a continuum, ranging from snoring to obstructive sleep apnoea (OSA).

They also emphasised that SDB is a medical condition. Consequently, only a physician can diagnose SDB in the USA and Canada (and in the UK). This means that the diagnosis would fall outside an orthodontist’s scope of practice.

Nevertheless, orthodontics does have a role in the interdisciplinary management of SDB, particularly in children. This includes conventional orthodontic treatment, screening, referral, and some interventions.

When we consider the nature of the disease, SDB is a heterogeneous condition with variable treatment responses. It is influenced by both anatomical and non-anatomical factors. The former include soft-tissue volumes, such as enlarged adenoids or palatal tonsils, fat infiltration, and potentially reduced skeletal volume. Non-anatomical factors include the neuromuscular function of the pharyngeal musculature.

Importantly, prepubertal OSA tends to resolve naturally during the transition to adolescence. This, of course, coincides with orthodontic treatment. As a result, we believe that orthodontics can help treat SDB.

Now I would like to review what I consider the most important recommendations and the underpinning research.

Craniofacial form and OSA.

Traditionally, we think that OSA is associated with certain craniofacial features, such as increased facial height, mandibular retrusion and craniofacial disharmony.  It is often stated that these are aetiologic factors in OSA. As a result, some suggest that correcting these skeletal problems will cure SDB.

The panel pointed out that there is limited evidence for these concepts.  The source of their evidence was 2 systematic reviews. 

One of these studies was published in the AJO-DDO in 2013. This review incorporated data from nine trials, of which eight were prospective case-control studies. The authors highlighted a potential association between craniofacial disharmony and paediatric sleep-disordered breathing. However, any differences were unlikely to be clinically significant. 

The Journal of Clinical Sleep Medicine published the other study in 2022. The authors identified nine studies. Four were cross-sectional, four were case-control studies, and one was a prospective cohort study. Both reviews were conducted with sound methodology. Nevertheless, they were limited by a small number of studies and high levels of uncertainty in the data. As a result, the AAO panel concluded that there was limited evidence for a connection between OSA and certain craniofacial features.

Their overall conclusion was that, due to the very low to moderate certainty level, ‘an association or lack thereof, between craniofacial morphology and paediatric OSA, cannot be supported by the data.’

Use of imaging in SDB

The panel concluded that imaging of the upper airway using CBCT or lateral cephalograms has no diagnostic value for SDB risk assessment or diagnosis. Furthermore, using changes in upper airway dimensions to suggest the efficacy of orthodontic treatment is scientifically flawed.

They based these conclusions on an International Consensus Statement on Obstructive Sleep Apnoea, published in July 2023. This was a large consensus meeting that evaluated OSA in great detail. The paper included 176 pages with just over 2000 references. I did not have time to read it in detail. However, in addition to the section on imaging, there was a section on the treatment of paediatric OSA. The authors pointed out that the first-line treatment was adenotonsillectomy. Importantly, I did not find a mention of orthodontic treatment.

I thought this paper was very important because it addressed one criticism that the AAO viewpoint was not based on medical research. I wonder if our collection of airway-focused orthodontics has read this paper?

Palatal expansion

The panel concluded that orthodontists should only provide palatal expansion for sleep disordered breathing management in patients with a clear orthodontic indication alongside a confirmed SDB diagnosis. I found this somewhat vague, and I interpreted it to mean that expansion should only be performed if a crossbite with a potential skeletal discrepancy is present.

They based this recommendation on two publications, one of which was a 2023 meta-analysis that found that RPE alone did not significantly reduce the apnea-hypopnea index. This included data from five randomised controlled trials and four non-randomised controlled trials, which together provided information on 595 patients. Most of the trials were rated as high risk of bias due to issues with blinding participants. The meta-analysis revealed limited evidence of a positive effect of rapid maxillary expansion.

The other study was a crossover randomised controlled trial examining the use of adenotonsillectomy and palatal expansion on AHI. I have written a blog post about this trial. I found it well-conducted. Its overall conclusion was that adenotonsillectomy is the primary treatment for OSA, and RPE may not provide benefits.

Again, these were good sources of evidence.

Functional appliances and growth modification

The panel concluded that there was no evidence to support the prophylactic use of functional appliances as a preventive measure for sleep disordered breathing. This is a logical conclusion because there are no studies showing that functional appliances can meaningfully change or alter the skeletal pattern.

Can we help in the treatment of sleep-disordered breathing? 

A key message from this research and discussion is that treating sleep-disordered breathing primarily falls to our medical colleagues. We clearly have a role in screening for sleep disordered breathing and referring patients. Once the physician has made an accurate diagnosis, we can contribute to relevant treatment, but we must collaborate closely with sleep specialists and other experts.

We can also offer care with maxillary expansion, but only in a few carefully selected cases. This is when there is a clear skeletal discrepancy, most often accompanied by a crossbite. It is absurd to expand maxillae simply because “we feel they are not wide enough” or that we need to increase the width by 3 to 5 mm to some hypothetical ideal imagined by an advocate who does not understand the existing research in this area.

What did I think?

I did not have the space or time to explore all aspects of this white paper, so I decided to focus on perhaps the four most controversial areas. I believe the evidence they used to support their recommendations was entirely relevant. The studies they selected were generally of good quality. The most striking finding, in my view, was that there were very few studies they could include. This is because there appears to be a lack of high-quality research.

This reinforces my opinion that, across this entire field, there is a surprising lack of evidence. This is a significant finding because, if evidence of benefit is absent, we cannot ethically promote or provide treatment that claims to address a disorder.

FInal thoughts 

This is an extremely useful and valuable source of information for all orthodontists. The recommendations are very clear. Importantly, they provide straightforward guidance on what we should and shouldn’t do. This means that if we perform treatment that disregards these recommendations, we may be acting unethically.

The response by some to the white paper has been unbelievably arrogant. Some detractors even suggest that their personal viewpoint or that of their ENT colleagues is more important than anything included in this document. Alternatively, some suggest the White Paper is flawed but do not specify where these flaws lie. Others have claimed that the AAO is protecting organised orthodontics. I don’t even understand what this means.

I have been an orthodontist for 40 years. Over this time, I have witnessed several “waves of nonsense”. These include orthodontic TMD treatment, non-extraction approaches for everyone, orthodontic vibrators, localised trauma to speed up tooth movement, orthotropics, and self-ligation. All have gained momentum, generated profit, and preyed on vulnerable patients. However, when science and the truth catch up with these claims, the new treatments vanish and we return to conventional, sensible orthodontics. This paper by the AAO is a significant step in the right direction.

If we accept and adhere to the recommendations of the White Paper, we can deliver a valuable service to our patients. This should also keep us sufficiently occupied.

What are your thoughts? Would you be interested in discussing this further in the comments?

    

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This new study is a population-based investigation into the effectiveness of interceptive orthodontics. A team from the well-known orthodontic department in Gothenburg, Sweden, conducted the study. The European Journal of Orthodontics published the paper. 

Interceptive orthodontics in practice: a 5-year population-based study

Anna Westerlund et al. 

EJO advanced access: https://doi.org/10.1093/ejo/cjaf113

The authors provided a clear introduction that outlined the rationale for the study. The aim of their study was to examine the delivery of orthodontic care within one district of the Swedish public dental healthcare system. In his region, interceptive care is delivered by general dentists in close consultation with orthodontists. Importantly, fixed appliance treatment is carried out exclusively by specialists. A total of 125 general dental clinics, staffed by 600 dentists, provide care to more than 380,000 children. 

The authors outlined that this publicly funded system does not aim for optimal outcomes in a small, highly selected group of patients from interceptive treatment. In effect, the aim of early treatment is to provide a brief intervention during the mixed dentition to reduce the need for treatment and eliminate the need for a second phase. This may be considered a successful outcome. They do not aim for ideal occlusion in all their patients at this point.  

When eligible patients are older, specialist practitioners provide fixed appliance treatment to achieve an ideal occlusion.

What did they ask? 

They did this study to

“Evaluate the scope of interceptive orthodontic care, specifically involving the use of activator, removable plate, quad helix and EOT appliances. This care was delivered by general dental practitioners under the supervision of orthodontic specialists”.

What did they do? 

They collected their data through a retrospective review of patient records from the electronic dental record system used in the public dental service in Västra Götaland, Sweden. 

The study population included all children and adolescents aged 0-18 years who were eligible for free interceptive orthodontic treatment. They were particularly interested in patients who had been treated with the following:

• Activator
• EOT
• Quad helix for posterior crossbites
• Removable plate for anterior crossbites

For each treatment, they defined it as successful, partially successful, or a failure.

They set out clear definitions for these; for example, for the treatment of an increased overjet with an activator:

• A successful treatment was an overjet of less than 5 mm
• A partial success was some improvement, but with an overjet remaining of >5 mm
• A failure was negligible or minimum effect

 They collected data from the medical record system for the period 2020-2024  

What did they find?

21,946 interceptive orthodontic treatments were carried out during the 5-year study period. 

Of these, 10511 involved removable plates. 6455 were treated with activator appliances. 3164 were quad helix appliance treatments, and 1816 were involving extra-orval traction. 

They then examined the patient records from 2020. These showed that 4,745 patients received interceptive treatment. They analysed the data more closely for 4,013 of these patients.

Activator Group. 

1,327 patients had received treatment with the Activator. Their mean age was 10 years. The mean treatment duration was 1.7 years (SD 0.6), with a mean of 11 (SD 5.2) visits per patient. The success rate was 56%. 

EOT  

The mean age of this group of patients was 11.2 years, and 101 patients received treatment. The average treatment duration was 1.1 years, with a mean of 11.2 visits. The overall success rate was 57 per cent. Most treatment failures were due to lack of compliance. 

Removable plate,

This group comprised 1,913 patients. The mean age was 11.0 and the mean treatment duration was 1.1 years, with a mean of 12.1 visits. The treatment success rate was 65%.

Quad Helix

672 patients received treatment with the quad helix appliance. The mean age at treatment start was 10.2 years, with treatment lasting 0.9 years. The treatment success rate was 82%. 

They also noted that appliances that rely heavily on patient cooperation achieved a fairly high success rate of just over 50%.

Their overall conclusion was 

“Interceptive orthodontic treatment in general dental practice can yield reliable, effective results when delivered with appropriate planning and follow-up”.

What did I think?

This is a very interesting study that was both ambitious and well executed. Studies of this nature are very difficult to carry out, and this team should be congratulated on the ambition and execution of their study.  

When we consider the results, we need to remember that the aims of the interceptive treatment they provided were not to achieve a perfect occlusion. The main objective of the treatment is to reach the eligibility threshold for cost-free care, thereby reducing the need for treatment and eliminating the need for a second phase. 

I emailed the lead author about some aspects of this study, and she also informed me. that if a treatment fails or there is a relapse resulting in IOTN grades 4 and 5, the patient is given a new opportunity for treatment with fixed appliances. 

We need to consider whether the findings of this study may not be fully relevant to the delivery of care in other countries. For example, in the USA, 2-phase treatment is likely to be more frequently used than in other countries. It could be argued that the final aim of treatment is always an ideal occlusion. Nevertheless, we know little about the effectiveness of phase I treatment, and it may not differ from the findings in this study.

Final thoughts

We need to consider whether this form of interceptive treatment is effective. From an individual patient’s perspective, one could argue that it is not, because treatment is not “ideal” at the end of the interceptive phase. However, from a public health perspective, the success rates are relatively high, indicating that interceptive treatment reduced the degree of malocclusion in this sample of patients. One could then argue that this is a good public health measure.  

However, in the long term, it is crucial that investigators thoroughly evaluate the treatment after the child has had the opportunity to receive Phase II intervention. Studies of this nature are essential for accurately assessing the true effectiveness of interceptive orthodontic care. This type of research, which evaluates the effectiveness of orthodontic intervention at a population level, is invaluable.

    

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Introduction

The American Association of Orthodontists published a white paper in 2019 on obstructive sleep apnea (OSA) and orthodontics, which provided an evidence-based, pragmatic guide for orthodontists on how best to manage these patients in an orthodontic environment. This new publication updates these guidelines, and we have summarised the main findings relevant to the management of children. The good news is that this article is Open Access: 

Sleep-disordered breathing and orthodontics: An American Association of Orthodontists white paper update

Juan Martin Palomoa, Julia Cohen-Levy,  Carlos Flores-Mirc,∙Rooz Khosravie, Mitchell Levine, Michael Pickard,Jackie Hittner, John Callahan, Steven M. Siegeli

AJO-DDO on line: DOI: 10.1016/j.ajodo.2026.01.014

These are the main findings of the group;

What did I think?

There have been controversies in orthodontics over the history of our specialty and in many respects, the role of the orthodontist in management of sleep disordered breathing is the 21st century controversy. Like most of these subjects, marginal and unsubstantiated views often dominate the narrative. These guidelines represent a pragmatic and balanced view based upon the best available evidence (and we would all agree that the current evidence base is lacking) written by a wide-ranging panel of experts. They are a very sensible set of recommendations and should be read by both generalists and specialists alike.

Orthodontists and other oral healthcare professionals are well-placed to play a role in the management of sleep-disordered breathing, but it must be evidence-based.

    

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Over the past 20 years, many studies have evaluated the effectiveness of the Twin Block compared with other functional appliances. Most of these have shown that, while the appliance is effective, the cooperation rate is not as high as we would hope. One recent development designed to improve cooperation is the modified clear Twin Block. Instead of being constructed from acrylic, this appliance is made from thermoplastic materials and cold-cure acrylic bite blocks. The aim of this design is to reduce bulk and weakness, improve aesthetics and comfort, and hopefully increase patient compliance. 

It has also been suggested that capping the appliance may reduce the side effect of extruding maxillary posterior teeth and proclining the lower incisors. The effectiveness of this appliance was examined in this new study. 

A team from Baghdad, Iraq, did this study. The European Journal of Orthodontics published the paper. 

A modified clear twin block appliance for treatment of class II malocclusion: a randomized clinical trial

Anosh A Haik et a

EJO advance access,  https://doi.org/10.1093/ejo/cjaf103

What did they ask? 

They did this study to answer the following question: 

“What is the effectiveness of a modified clear twin block compared to a conventional Twin Block “?

What did they do? 

They carried out a multi-centre, single-blinded, randomised clinical trial with two-arm parallel groups. 

The PICO was 

Participants 

Orthodontic patients who were rapidly growing with a skeletal Class 2 malocclusion with an OVA jet greater than or equal to 8 mm 

Intervention 

A modified clear Twin Block made from thermoplastic material. With ramps made from cold cure ccrylic. An expansion screw is installed in the upper component of the appliance.

Comparison. 

Standard acrylic Twin Block. 

Outcome 

The primary outcome was a cephalometric evaluation using many cephalometric measurements. Secondary outcomes. 

These were linear measurements of the teeth made from scanned maxillary models aligned and superimposed on palatal rugae. In addition, the patients completed a questionnaire on their perceptions of the appliance, including pain and discomfort. 

They asked the patients to wear their appliances for 24 hours a day. The operator monitored patients’ compliance every 2 weeks and evaluated expansion progress and overjet changes every 4 weeks. The final record was taken after the overbite correction, and the buccal segment occlusal relationship was fully corrected. 

They conducted a clear sample size calculation to detect a 1.5 mm difference in overjet reduction between the two appliances. This indicated that they required 21 patients in each arm of the trial. To account for a potential dropout of 15%, they recruited a total of 48 patients. 

They used a pre-prepared randomisation, generated remotely by an independent person. Concealment was achieved using sealed envelopes.

 All data collection and measurement were done blind. The statistical analysis was rather simplistic, using univariate statistics across many variables. As a result, there is a risk of false positives due to the multiple related measurements. We need to bear this in mind when we look at the results.   

They conducted the study across several government-specialised dental centres and a private dental clinic. Although they did not specify the number of centres or operators involved in the study 

What did they find? 

They randomised 25 patients to each intervention, and all patients completed the study without any dropouts. The study began in September 2022 and was completed in June 2024. 

The mean age of patients at the start of treatment for the Twin Block group was 12.16 years, and for the modified Twin Block group, 11.76 years.

The active treatment duration was 9.14 ± 2.9 months for the Twin Block group and 8.8 ± 2.1 months for the modified Twin Block group.

 At the start of treatment, there were generally no differences between the two groups. However, there were statistically significant differences for SNA, SNB, and SN-Pog. They addressed this imbalance by carrying out an analysis of Covariance to adjust for these differences. However, they did not report this in any detail.

The team produced a large amount of data at the end of the treatment. Most of this concerned cephalometric measurements. As with most studies of this nature, we need to bear in mind the difference between statistical and clinical significance. In this respect, most of the differences were in the order of 1-2 degrees. Although they were statistically significant, I felt they were not clinically significant. However, the upper incisors were retroclined an additional 6 degrees with the conventional Twin Block. This suggests that the treatment may make many small changes that contribute to the overall treatment effect. This is similar to the results of many other studies into the effects of functional appliances and the results do not really add to our knowledge.

 There were no differences in treatment duration. The active treatment duration was 9.14 ± 2.9 months for the Twin Block group and 8.8 ± 2.1 months for the modified Twin Block group.

 When they evaluated patient perceptions of their appliances, however, they found several differences between the two treatments. The results showed that the modified twin block group of patients had a better treatment experience. This was particularly relevant when considering factors such as appliance breakage, difficulty in keeping the appliance clean, changes in speech during appliance wear, and improvement in teasing or bullying. The modified twin block group also had a less pronounced effect on their quality of life with respect to embarrassment, speech, and general appearance.  

 Their overall conclusion was 

“The modified Twin Block was effective in treating patients with Class II mandibular protrusion. It is comparable with slightly advantageous results to the standard Twin Block Appliance”.

What did I think?

This was another study that provides us with some useful information on the Twin Block appliance.  The trial was conducted well and reported in accordance with the CONSORT guidelines.  

One major strength of this study was that it was carried out in the real-world setting of government-run clinics with multiple operators. This is in contrast to many other studies conducted in university dental schools with resident operators. As a result, its findings are generalizable. However, I was unsure on the number of treatment centres and operators. This information was important and it should have been included in the paper.

The authors drew attention to several shortcomings in their study. The most important of these was that they only followed the patients until the completion of the functional appliance phase of treatment. As a result, they did not take into account the effect of any follow-up fixed appliance treatment or potential relapse. This is particularly important and is characteristic of many functional appliance trials. I hope the authors continue this study and report their end-of-treatment data.

 My other criticism is a favourite bugbear of mine. This was because they led on cephalometrics as their primary outcome measure. We know from many cephalometric studies that these measurements are only relevant to orthodontists and are clinically insignificant, yet statistically significant. In fact, in several parts of the discussion the authors mentioned that the MTB resulted in better treatment effects than the CTB. However, this was not supported by the data.

Nevertheless, it was great to see that they used a patient-based outcome measure that reflected their patients’ values. While I was not familiar with this measure, it certainly seemed to indicate considerable advantages of the modified Twin Block appliance. In general, patients appeared happier with the modified Twin Block than with the acrylic Twin Block. However, it was important to note that this was not reflected in the cooperation rates, as all patients completed the study. 

Final comments 

With all papers, we need to consider whether the findings would persuade us to change our practice. I certainly found this paper very interesting, and I would use this appliance on a few selected patients, as I believe it may have value in the future. 

I would like to congratulate the authors on this very useful and clinically relevant research project. Nevertheless, I think that this paper would have been improved by better refereeing, as there were several areas that were not entirely clear.

    

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This is not a post about a clinical subject; an established orthodontic research team conducted this study. I, therefore, thought it was relevant to my blog and was certainly a change from looking at “airway” papers.

A team based in the beautiful South of England and Zurich conducted this study. The Journal of Dental Research published the paper. This paper is open access.

Transcription Accuracy of Automatic Speech Recognition for Orthodontic Clinical Records

R OKane et al

Journal of Dental Research, DOI: 10.1177/00220345251382452

I have a conflict of interest as I know this research team well.  Martyn Cobourne and I come from a small village in the rural county of Worcestershire and went to the same schools and played in the same park when we were children.

What did they ask?

They did this study to answer this question. 

“What is the transcriptional accuracy of ASR systems in dentistry using narrated orthodontic clinical records?” 

What did they do? 

They carried out a cross-sectional study with the following stages: 

They identified 10 distinct automatic speech recognition systems for orthodontic clinical records. Four of these were commercially available systems. For example, Dragon Medical 1. 

The second category was standalone speech-to-text systems that provided direct access to widely available automatic speech recognition models. Examples included GPT-4.0 Transcribe and Whisper OpenAI. 

The third category was an experimental ASR, augmented by natural language processing and Large Language Models (LLM) that use generative error correction. This was called GPT40Transcribe Corrected.

They then dictated from prepared orthodontic clinical records, including diagnoses and treatments, to generate transcripts using various ASR systems. 

Interestingly, they evaluated all systems in the presence or absence of background noise and across variations in narrator accents. 

They then assessed each system for transcriptional, lexical, and semantic accuracy using validated word- and character-error metrics. The primary outcome was the Domain Word Error Rate (DWER), which assesses transcription accuracy with respect to clinical terminology. 

What did they find?

They produced a large amount of data. There were significant differences between the systems in terms of DWER. 

They found that GPT4o TranscribeCorrected outperformed all other systems, achieving a DWER of only 3.47%. GTP40 Transcribe and Heidi Health were consistently ranked second and third best, with DWERs of 7.6% and 6.1%, respectively. 

Interestingly, the commercially available systems did not perform as well. For example, Dragon Professional Anywhere ranked worst across all transcription error metrics, with a DWER of 48%, and Dragon Medical One ranked second-worst, with a DWER of 29%.

With the exception of GPT4o and Transcribe Corrected, the systems had considerable difficulty recognising domain-specific words. They also found that background noise increased the word error rate. However, this effect was system-dependent, with the two GPT4o variants and Heidi Health showing the greatest resilience. They also found that speaker accent had only a minor influence. 

The authors highlighted several orthodontic terms that were mistranscribed across the systems. They included these in a very useful table. I do not have space to include them all in this post. However, it was interesting to see that terms such as “Essix retainer” were consistently transcribed as “Essex”, the county, and that terms such as “mesially” were transcribed as “nasally”, “easily”, and “measly”, with a 75% mistranscription rate across all systems. (This is exactly what happened when I was dictating this post into Whispr Flow!)

Their final conclusion was

“There was significant performance variability amongst the tested ASR systems. All were capable of introducing clinically significant mistranscriptions. We need to be cautious about using this technology at the moment, as it requires considerable checking.”

What did I think? 

I’ve always messed about with computers and their technology since the early days of the personal computer. In the past, I have tried many dictation systems, and they were all abject failures. Recently, I have been using WISPR Flow to dictate this blog, and it appears to be an excellent package. I was therefore very interested to see this study. 

The authors did the study well and wrote a clear paper.. The Journal of Dental Research published the paper. This is a difficult journal to get a paper accepted in. I have never managed to achieve this. 

I found the findings interesting and pointed us toward using various packages.  

This is clearly going to be a very fast-moving field. I’m not sure which package to use; however, it is important to note that the non-clinical packages were surprisingly effective compared with those developed for clinical use. 

We also need to consider what an acceptable error rate is. This is rather difficult because the consequences of different errors are likely to vary. For example, misidentifying a tooth for extraction is likely to have greater consequences than a mistake in recording a molar relationship.

The authors of the paper also highlighted the risk of “hallucinations”. They explained these as “a type of output error where the model generates fluent, coherent text that is entirely unrelated to or ungrounded in the source audio input”. The fabricated transcriptions often appear convincing but do not match the actual spoken content. In this study, they found hallucinations that included invented discussions on tooth restorations or alternative treatments. It is crucial that we identify these, as they have the potential to cause confusion or harm.”

This is an important paper for all clinicians. I look forward to other developments in this fast-moving field.

    

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A team from Munich, Germany, did this study. The AJODO published the paper.

Objective assessment of wear time during orthodontic aligner therapy using microsensors: A randomized controlled trial

Hisham Sabbagh et al

AJO-DO on line.  https://doi.org/10.1016/j.ajodo.2025.10.008

What did they ask?

They did this study to;

“Objectively assess the wear time of aligners using micro sensors and to evaluate whether patient awareness of monitoring affects wear time.” 

What did they do? 

They conducted a prospective, single-centre, two-arm, parallel, randomised controlled trial with a 1:1 allocation ratio. 

The  PICO was… 

Participants

Orthodontic patients treated in a university clinic requiring treatment for crowding or spacing.

Intervention

“Aware group” Theramon orthodontic wear timer. The operator told this group of patients about the monitoring.

Comparison

This group also had Theramon times they did not inform them that they were being monitored

Outcome

The primary outcome was wear time (hours/day).

The operators reviewed the patients every 14 days for 6 appointments. This corresponded to a period of approximately 12 weeks. They asked the patients to wear their aligners for 22 hours/day.

They measured appliance wear time by recording temperature with a Theramon microsensor embedded in the aligner material.

The statistician conducted a clear sample size calculation indicating that 40 participants were required for the study.

The team used a prepared randomisation, and allocation was done by using sealed envelopes.

Data analysis was done blind.

They conducted a clear and relevant data analysis using exploratory statistics and multivariate analyses, with wear time as the dependent variable.

What did they find?

They randomised 43 patients into the two groups. Three discontinued the intervention, leaving 40 patients in the final analysis. 

When they examined the wear time of the aligners, they found substantial individual variation. 

The daily wear time ranged from 1.5 to 22.5 h/day, with a mean of 13.7 h/day in the monitoring unaware group and 5.8-21.8 h/day (mean 16.7 h/day) in the monitoring aware group. The overall mean wear time was 15.2 h/day, representing 67% of the required time.

The wear time of subjects in the “aware” group was, on average, 4.4 h/day longer than that of subjects in the “unaware” group (95% CI 1.88 to 6.93).

Their overall conclusion was

“Awareness of monitoring improved patient compliance and can be used as an effective strategy to enhance WT during aligner therapy in adults”.

What did I think?

This was a well-conducted and clearly written study. It was great to see that the authors had followed the CONSORT guidelines very closely, which made the interpretation of their study relatively straightforward. The paper is also open access, so anyone can read it. It was refreshing to see such a nicely done piece of work.

I thought the findings were interesting and clinically relevant. In many respects, these findings are similar to those of other studies that used timers for removable appliances. Importantly, this reflects the “real-world” experience of removable appliance wear and reinforces the finding that our patients rarely adhere to our wear time recommendations. Importantly, this study suggested that the results of part time wear of Twin Blocks was not differerent than full time wear.

It also strongly suggests that informing patients of monitoring will increase compliance with our instructions. This is a very useful conclusion. Importantly, the Theramon timer is a minute-by-minute timer and is more accurate than the Invisalign compliance indicato which is a visual aid for compliance. 

I hope that the team will continue their study through the end of treatment. This would provide valuable information on the effect of wear time on the final clinical outcomes. 

I hope that research teams are conducting further studies on aligners to this standard.

    

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We are seeing an increasing number of studies examining the effects of breathing on skeletal growth and other important factors. These developments are good news for those of us seeking evidence on these relationships. This new paper in the high-impact AJO-DDO examined the effects of removing adenoids on respiration, craniofacial development, and posture.

A team from Istanbul, Turkey, did this research

Significant changes in respiration, craniofacial development, and posture: A multidisciplinary study on the effects of adenoidectomy

Meral Gurkan, et al

AJO-DDO advance access: https://doi.org/10.1016/j.ajodo.2025.09.029

What did they ask?

They did this study to 

“Assess changes in respiratory patterns, craniofacial development, and head and neck and overall body posture in children who have undergone early adenoidectomy and those who have not”. 

They provided an extensive, yet, traditional literature review on this subject. Importantly, they noted that mouth breathing is traditionally associated with a distinct craniofacial appearance (adenoids facies). They drew attention to a comprehensive review published in 2025, which showed that mouth breathing induces craniofacial morphological changes and significant alterations in mandibular, lingual, and palatal positioning. However, this was published in a predatory journal. The conclusions of this study are very different from those of a recent paper on a similar subject, published in the AJO in 2025. 

I guess at this point you are sensing the direction that this blog post is taking!

What did they ask?

They wanted to

“Evaluate children presenting with respiratory obstruction because of adenoid hypertrophy”.

What did they do? 

To answer this question, they conducted a retrospective cross-sectional study. They looked at three distinct groups of participants. 

• Group 1 were patients who were diagnosed with adenoid hypertrophy who presented at a later stage and were planned for removal of their adenoids. 
• Group 2 were patients with respiratory obstruction because of adenoid hypertrophy who had undergone early surgery and completed 3 years post-operative follow-up. 
• Group 3 comprised subjects with no pathology or systemic disease causing respiratory obstruction, and they exhibited normal nasal breathing. 

They evaluated all the groups at one time point. All the children in the study were aged 6 to 10 years. The median age of each group was 8 years.

They used the following outcome measures:

• The NOSE scale. This consists of five questions that assess patients’ respiratory symptoms.
• Peak nasal inspiratory flow (PNIF). This provided quantitative data on respiration. 
• The head and neck posture. 
• A comprehensive orthodontic clinical examinations, including:
• Radiographic records
  • Panoramic radiographs
  • Lateral cephalogram and analysis
  • PA head and hand/wrist X-rays
  • Tooth measurement from dental casts

They did a power analysis using the gonial ratio (S-Go/N-Me %) from a similar study. The clinically significant difference they aimed to detect was 0.4%. As a result, we can assume that the gonial ratio is the primary outcome of the study.

What did they find?

The team carried out an extensive analysis of their data. I felt that these were the main points.

When they examined differences in the outcome measures between the groups, they found no differences in any of the postural measurements.

 They conducted univariate analyses of 32 Cephalometric measurements. This increases the likelihood of achieving statistical significance and potential false positives. They found statistically significant differences in 7 out of the 32 cephalometric measurements. But these were very small, and I felt that they were not clinically significant.

There were no differences in the dental cast measurements. 

However, the later adenoidectomy group had greater nasal obstruction (NOSE score) and lower PNIF. But, the NOSE scores were all within normal limits.

Their overall conclusion was that.

“Early adenoidectomy improves respiratory and craniofacial growth, resembling normal breathing. Delayed surgery leads to persistent mouth breathing and negative growth outcomes”.

What did I think?

This was an interesting study that aimed to answer a clinically relevant question. However, it is also a good example of how a cursory reading of an abstract and a paper can lead to misinterpretation of the results and conclusions. 

The authors collected a large amount of data on 34 outcome measures and ran simple univariate statistics between the groups. This increases the chance of false positives. They then concentrated their discussion and conclusion on these differences.   However, this did not include their primary outcome of gonial ratio, which was not different between the groups.

This was a traditional cephalometric trawl looking for statistical significance and concentrating the discussion on the “significant” measures totally ignoring the other 25 “non significant” outcomes.

When I examined the cephalometric data, most statistically significant differences between the groups were small. I did not find any clinically significant differences. The authors’ discussion and conclusions were based on statistical significance rather than effect size. However, they noted that we should interpret the study cautiously, given the small effect sizes. Nevertheess, this was not reflected in their conclusions.

I think it is also very relevant to consider the findings in this paper alongside a recent systematic review. I have posted about this review previously.  In this systematic review, the authors identified an effect of adenoid removal on skeletal parameters, but it was very small and likely not statistically significant. 

It was also interesting to see that they based their sample size on a small difference in gonial ratio. I presume that this was the primary outcome of the study. However, when they analysed this outcome, there were no differences between the groups for genial ratio.  This raises questions about the study’s power.

My conclusions.

The data in this study support the conclusions of the previous systematic review. As a result, I feel that this study would have benefited from closer statistical refereeing and less emphasis on statistical rather than clinical significance. 

Some readers may feel that I am being to critical and this post represents my confirmation bias. This is not the case I have simply carried out a critical appraisal.

I also realise that I have now done several posts on breathing. However, it appears that research is increasing in this area and it is important that we appraise it. Next week I am doing a post about aligners.

    

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Introduction

Many of you who peruse Orthodontic Facebook groups will be aware of a recent debate surrounding the airway chaired by Kyle Fagala. This has become an increasingly emotive topic. I must admit that I sit firmly on one side of this fence having read and assimilated the evidence (something that I firmly believe should be a prerequisite to any claims made in either direction). Kevin O’Brien did a typically clear and incisive summary of the discussion on his Blog last week.

Lack of evidence?

I note that one thing that those on opposing sides of the ‘aisle’ could agree upon was a lack of evidence. Without wishing to present a contrarian view, I think this is sometimes a slightly lazy assumption that we make. As we know, evidence is often inaccessible for a range of reasons. Many of you will know that we have tried to remedy this by producing a simple Instagram resource involving potted summaries either of high-quality research or pivotal topics (@OrthoReads) driven by the inimitable Chong Jun Ai. We have been fortunate that Carlos Flores-Mir agreed to summarise four papers on the airway this month. I have summarised these below and would encourage you to have a read of these.

Paper 1

The first paper is an excellent crossover clinical trial – the highest possible level of evidence which suggests that even in children both with tonsillar enlargement and a narrow palate removing the adenoids/tonsils first is the most effective way to reduce obstructive sleep apnea events and improve oxygenation. Any benefit of palatal expansion was marginal to none even in this cohort with transverse maxillary constriction.  Kevin has previously posted about this trial.

In this study, a group of 32 non-obese children (mean age 8.8 years) with a Class I skeletal relationship but significant tonsil enlargement (Grade III/IV) and maxillary constriction were treated in a crossover randomized trial with adenotonsillectomy (AT) and palatal expansion (PE). One group received AT first, while the other had PE first. If a child still had OSA (AHI > 1) after 6 months, they crossed over to receive the second treatment. The primary outcomes were changes in the Apnea-Hypopnea Index (AHI) and Minimum Oxygen Saturation (MinSaO2).

Most of the improvement in breathing (AHI reduction) and oxygen levels (MinSaO2) was attributable to AT rather than the PE. Improvements in the lowest oxygen levels during sleep were primarily driven by the initial severity of the condition. Those receiving AT first showed much better overall outcomes. The combination of initial AHI severity and AT as the first intervention explained 95% of AHI improvement. PE had only a marginal effect on sleep apnea parameters when adjusted for other factors. The degree of improvement in AHI or oxygen levels when used as a standalone or follow-up treatment was not comparable to the impact of AT.

Key clinical take-home message: If a child has both enlarged adenoids/tonsils and a narrow palate, removing the adenoids/tonsils first is the most effective way to reduce obstructive sleep apnea events and improve oxygenation.

Paper 2:

Ther next paper challenges myopic ‘magic bullet’ approaches to OSA management (such as the putative benefits of orthodontic treatments). The authors argue for a transition from the “one-size-fits-all” application of Continuous Positive Airway Pressure (CPAP) toward a patient-specific approach for Obstructive Sleep Apnea (OSA). OSA is a chronic, systemic, inflammatory, heterogeneous disorder driven by diverse physiological mechanisms.

They propose three non-anatomical (ineffective upper-airway muscle responsiveness, a low arousal threshold, and high loop gain (instability in ventilatory control)) and one anatomical (upper airway narrowness) factor involved in adult OSA. The applicability of this concept in children is unknown. Any given patient has one or more of these factors. By identifying these specific underlying causes, clinicians can move beyond CPAP to multiple consecutive or simultaneous targeted therapies such as oral appliances, upper-airway surgery, oxygen therapy, or pharmacotherapy.

Take-home message: Integrating subtype profiling into clinical practice is essential to successful OSA management.

Paper 3:

This is a clinical practice guideline from the American Thoracic Society (2024).

The authors explore the lack of consensus on the management of persistent OSA in children following adenotonsillectomy (AT) (the accepted first line treatment). This accounts for 40% of those having AT for OSA. Recognizing the limitations of a universal approach, the multidisciplinary panel provided evidence-based recommendations for six targeted interventions, one of which falls within dentists’ scope of practice. The guideline suggests that children with persistent OSA and site-specific airway obstructions concomitant to relevant craniofacial features may be considered candidates for dento-facial orthopedic treatment.

Take-home message: Although dentists may play a role in managing children with OSA, due to very low evidence certainty, the authors emphasize shared decision-making to optimize interdisciplinary pediatric outcomes.

Paper 4:

The final article selected by Carlos Flores-Mir is a meta-analysis evaluating the diagnostic accuracy of questionnaires and clinical examinations for pediatric sleep-disordered breathing (SDB) compared to the gold standard, polysomnography (PSG). This is an important question given the challenges of diagnosing genuine OSA.

Most clinical tools lack sufficient evidence to replace PSG lacking both diagnostic sensitivity and specificity. Only one tool (the Pediatric Sleep Questionnaire, or PSQ) showed diagnostic accuracy high enough to be considered acceptable as a screening tool.

Take-home message: While dentists may be well placed to identify anatomical risk factors, the use of validated tools, such as the PSQ, is essential. Specifically, these may help for triage and to make appropriate referrals. It is important to not simply assume that a child has OSA based on specific craniofacial characteristics or breathing pattern. Identifying high-risk children through these screenings enables more efficient prioritization of limited PSG resources within the health system as part of an interdisciplinary approach

We hope that you find this information useful.

    

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