A new controversial systematic review on early Class II treatment.

Early treatment of Class II malocclusion remains somewhat controversial, despite high-quality research evidence indicating limited benefits for orthodontic outcomes. Nevertheless, there are likely to be benefits in terms of reducing incisal trauma and increasing the self-esteem of young children.

I was, therefore, surprised to see this new, controversial systematic review suggesting that early orthodontic treatment enhances treatment outcomes and may reduce the need for extractions and prolonged fixed appliance therapy in adolescence.

Several readers of my blog have drawn my attention to this paper and asked me to share my opinion on it in a blog post.

A non mainstream journal published. this paper. I am not sure how reputable this journal is, and we are becoming increasingly aware of potentially predatory journals. I do not normally comment on papers from this source, but the controversial findings do require close attention.

A team from Timișoara, Romania, did this review. The Children Journal published the paper. 

What did they ask?

They did this study to 

“Compare the outcomes of early vs. late orthodontic treatment to assess their relative effectiveness”. 

What did they do? 

They did a systematic review using fairly standard methodology. 

The PICO was 

Population

Children aged 6-14 years old with primarily Class II malocclusion. 

Intervention

Early orthodontic treatment initiated during the deciduous or early mixed dentition stage.  (6-9 years old)

Comparison  

Late orthodontic treatment initiated during the late mixed or early permanent dentition stage (10-14 years old). 

Outcome 

Skeletal, dental, and airway-related changes. Need for extractions or fixed appliances and long-term stability. 

They included randomised trials, cohort studies, and retrospective studies in the selection criteria. 

The first phase of their literature search used a new software called Elicit AI. The authors then reviewed the papers. They did not review grey literature or clinical trial registries, and confined their included papers to peer-reviewed published articles.

Importantly, they only included papers published between 2015 and 2025 

The team conducted standard data collection and evaluated the risk of bias for all papers using the Cochrane Risk of Bias tool. Because they identified high heterogeneity, they did not perform a meta-analysis. As a result, they decided to conduct a qualitative synthesis of the data.

What did they find?

They identified 11 studies for inclusion in the systematic review. They stated that 8 of these were randomised trials, two were retrospective studies, and one was a prospective cohort study.

I found their data descriptions rather confusing. For example, they stated that the mean starting age in the early treatment studies was not different from that in the later treatment studies. This suggests an overlap that did not reflect the aims of the study.

Importantly, they provided extensive information on the statistical significance of the studies. However, they did not report any effect sizes. I could not help feeling that they were confusing statistical significance with clinical effectiveness, which increased my concerns about their methods.

Their overall conclusion was:

“This systematic review demonstrates that early orthodontic intervention, especially when timed with craniofacial growth phases, can provide measurable short-term benefits in skeletal development, dental arch expansion, and airway improvement in pediatric Class II malocclusion”.

What did I think?

I found this systematic review confusing to understand and interpret.  I could not agree with the conclusions they drew because the paper had several major flaws. 

These were:

1. An obscure journal published the papers. Some pay-to-publish journals vary in quality, and they have been criticised for the quality of the refereeing and editorial processes. Further details on predatory journals may be found following this link. Details of the journal and its publisher are available here. 
2. I was also concerned about their reporting and the accuracy of their data. For example, they reported identifying eight randomised trials. However, five of the reports were from the same study, substantially reducing the number of separate studies. They also suggested that one of the papers (Mandall 2022) was an early treatment study. This was not the case. It was a study of the timing of treatment provided to children aged 11 to 14 years.
3. They stated that they used the Cochrane Risk of Bias tool to assess potential bias in the publications. However, this was inappropriate for the cohort and retrospective studies they included.  
4. They use the Elicit software to identify trials. This is new technology, and the Elicit software’s sensitivity has been shown to be poor compared with traditional methods. Indeed, a paper published by the Cochrane Collaborationsuggested that the Elicit software was not sensitive enough to be used in current clinical systematic reviews. Although its use appears promising.
5. I was uncertain why they included data only from 2015 to 2025. This excluded some of the classic Class 2 studies published before 2015. Importantly, these studies did not support their conclusions, which stated that early treatment ‘is no more effective but is less efficient’. 
6. They did not take into account the findings of a Cochrane review on the treatment of Early Class II malocclusion. Again, this does not align with their conclusion. The conclusions do not appear to be based on the data reviewed, and I wonder whether they were therefore coloured by the authors’ views.

I am sorry to be so critical of a publication that has been published in good faith. However, it would have benefited from even the most cursory referee’s evaluation. Members of the paediatric dentistry and orthodontics editorial board of the journal are listed here. 

Final comments

Finally, am concerned that this paper directly contradicts the best available evidence on the timing of Class II treatment. It has already been cited by some proponents of early Class II treatment. I hope this blog post can help counter some of the claims currently being made.