Should we recommend early overjet reduction to prevent trauma?
There has been a large amount of research into early Class II treatment. This post is about a recent update on therapy preventing incisal trauma.
We have previously posted about this subject several times. I posted a detailed discussion on the risks and prevention of trauma back in 2013. Several people made great comments in the discussion. These reinforced the general feeling that there was some evidence for early treatment. However, the evidence was not strong and we needed to factor this into discussions with our patients. In 2018 we updated our Cochrane review on Class II treatment and suggested:
“Early treatment resulted in a 12% reduction in the incidence of incisal trauma”.
Some time has passed, so I thought this update was timely.
A highly respected team from London, South of England, and Zurich, Switzerland, did this study. This group also runs the excellent Evidence Based Orthodontics Facebook, which is a breath of fresh air!
The British Dental Journal published the paper.
Martyn T. Cobourne, Andrew T. DiBiase, Jadbinder Seehra and Spyridon N. Papageorgiou
BRITISH DENTAL JOURNAL | VOLUME 233 NO. 5 | September 9 2022
What did they ask?
They did this review to:
“Explore the association between early overjet reduction and dental trauma in the context of current best evidence”.
What did they do?
This was a review of the literature. It is essential to realise that this was not a systematic review. However, this focused review included evidence from trials and systematic reviews. Importantly, this was done to provide general advice to a non-specialist reader.
What did they think?
They provided great concise information in this paper. Firstly, the team pointed out that early treatment effectively reduces overjets. Nevertheless, treating early is no real advantage at the end of all care in adolescence. This conclusion is generally accepted and is not controversial.
They then looked closely at the trauma data from the large Class II studies conducted at UNC, Florida, and the UK. In addition, they included data from a more recent study that looked at early headgear activator treatment.
They reported this data in a Forest plot. They stated:
“In simple terms, the risk of incisor trauma was reduced by around a half (from 25.5% to 14.2%) in children having their overjet corrected early. But there was a large variation around these trials”.
They rightly pointed out that the data from these studies used different criteria for trauma. Notably, there was an overall lack of clinical detail in the type of trauma. As a result, the data was of low to moderate quality.
They also drew attention to the following.
- The most significant trauma risk is at an age far too early to start any treatment. So even early therapy at age 9 won’t help these children.
- The data suggest that headgear is more protective than functional appliance treatment.
- On an individual basis, only the North Carolina trial found any significant difference in trauma between groups. This trial also had the most potential bias (KOB note).
Their overall conclusion was:
“We should not advocate early treatment for all children with Class II malocclusion. We should consider starting early when we think that there is an increased risk of dental trauma”.
What did I think?
I was very interested in a detailed and sensible analysis of this data. I spent many years looking at this problem in our own large trial and close involvement with the earlier Florida and UNC trials. Firstly, I would like to consider their comments on the trauma data from these three large trials.
I believe they correctly point out that we used different criteria for trauma in our studies. If we could turn the clock back to the late 1980s and early 1990s, we would have coordinated these studies better. However, in those days, large RCTs were new to orthodontics. In fact, we used a book on RCTs to plan the UK study. In effect, we were not as good at identifying the importance of outcome measure selection and sample sizes as we are now.
As a result, there is a degree of uncertainty around the trauma data.
Nevertheless, we cannot discard this data. Instead, we should factor this into discussions with our patients. This is also their conclusion when they suggest we should identify children at risk of trauma.
We, therefore, need to consider how we identify this risk. It is easy to suggest that if a young person is a skateboarder, they may be at higher risk. But what about contact sports? They are unlikely to play full-contact rugby, and the risk of trauma from football is low. I am not sure about the “hardball” sports of baseball and cricket for fielders. A lot of trauma takes place at the swimming pool! Perhaps a solution is to follow lacrosse, where mouthguards and helmets are compulsory for all players. We must also remember that trauma commonly occurs in playgrounds without identified sports. As a result, the situation is even more complex!
Having carried out research and interpreted many papers in this area. I need to consider what I would do as a clinician. I would discuss the summary of this research with the young person with an increased overjet. Furthermore, I would point out that there is a chance of them damaging their front teeth, and treatment may reduce this chance. But I would emphasise that we will not eliminate the possibility of trauma. It is up to them to decide. But at least we have some evidence.
Emeritus Professor of Orthodontics, University of Manchester, UK.