Can we intercept malocclusion? A five-year population-based study.
We would all like to intercept the development of malocclusion. In theory, interceptive orthodontics aims to manage arch-length discrepancies and promote favourable skeletal development before the permanent occlusion is fully established. These aims are laudable. Unfortunately, evidence for the benefits of interceptive treatment is limited. There have been some randomised trials of the early treatment of Class 2 malocclusion. However, these studies have shown that it is no more effective than waiting until the occlusion has developed before starting treatment.
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.
Emeritus Professor of Orthodontics, University of Manchester, UK.
The subtleties of individualised treatment verses trying to deal with an homogeneous group. The researchers have done well to run such a study (about 4,000 cases!). The ‘success’ rate after treatment is also gratifying. I must say I am blunt with my early treatment cases and often I use one or more appliances with simplicity, ease of use, comfort and not interfering with the child socially, front and centre of my thinking. That EOT is just as effective but quicker than functional appliances is not surprise to me, although some would argue the rationale for early Class II treatment is to reduce the risk of trauma and a functional appliance may reduce overjet faster. Me, I don’t lean on that rationale.
Success rates in 10-11 year olds matches my experience. Quad helixes are a fixed appliance in my practice and the 80% success rate may reflect that.
When I then see the patient aged 12 with good improvement such as some maxillary expansion and Class I (or better) molars, I am more certain my treatment will progress as planned to more reliably achieve a good result with fewer compromises, and perhaps controversially, fewer extractions.
All this then needs to be considered through the differing economic lenses of different countries. A public health system that shifts treatment from ‘suitable for comprehensive treatment’ to ‘not suitable for comprehensive treatment’ may well save the public purse. In a private system some parents will simply want ‘the best’ for their child and (IMHO the flawed concept of) ideal comes into play. Don’t misinterpret me, I hate poor sloppy, uncontrolled orthodontics, but the idea of one singular occlusal, dental aesthetic or facial goal is grossly oversimplified and counterrational.
Again, I congratulate and thank the authors.