Is early orthodontic treatment based on evidence? Looking for “needles in a haystack”.
One of the most controversial areas in orthodontics is about the timing of orthodontic treatment. There are many orthodontists who are starting to introduce “early or interceptive” treatment into their clinical practices. But is this evidence based? This systematic review provides us with good information on early orthodontic treatment.
R. Sunnak, A. Johal, P.S. Fleming
Journal of Dentistry 43 (2015) 477–486
A team from Queen Mary’s University, London did this interesting and clinically relevant review.
What did they ask?
In the introduction the authors pointed out that the current trend to provide early or interceptive treatment is based around the concept of reducing the need for further treatment or attempting to reduce the severity of the developing malocclusion. The conditions that are commonly “intercepted” are
- Facial growth problems
- Impacting canines
- Development of dental crowding
- Correction of overjets
This philosophy is also reflected in the American Association of Orthodontists guidelines. These suggest all children should receive an orthodontic screening at age 7-8 years. However, we need to consider that while a screening may identify a developing problem, it is essential that any treatment for the problem is effective. Currently, evidence in this area is lacking and this team did this systematic review attempted to answer this question.
They aimed to “assess the effectiveness of a range of orthodontic interventions provided to children under 11 years both in the short and long term”.
What did they do?
They carried out a standard systematic review with the following criteria
Study design: RCT or CCT
Participants: Children under 11 years old
Interventions: Any interceptive treatment
Comparator: Untreated controls or participant having another active intervention
- Improvement in arch relationship,
- Change in the position of teeth,
- Change in skeletal discrepancy.
- They also had secondary outcomes of:
- Need for a second phase of treatment
- Patient satisfaction
- Duration and process of treatment
- Any harms
- Need for extractions.
They did a high quality systematic review in which they identified the relevant literature from electronic sources, carried out a quality assessment and then only included the trials that were at low risk of bias. They extracted the outcomes and assessed the overall strength of evidence using the GRADE approach.
What did they find?
They identified 20 studies that were of low risk of bias. These looked at the following:
- Short term effects of skeletal growth modification for Class II and Class III malocclusion.
- Correction of anterior open bite
- Correction of posterior crossbite
- Interceptive extractions to reduce crowding
- Improving the position of ectopic maxillary canines
They provided a large amount of data. I have summarised this with respect to the conditions that they evaluated.
Class II growth modification
Early treatment resulted in small but not clinically significant effects on skeletal growth. These differences were not maintained at the end of a second and final phase of treatment. However, there was some reduction in incisal trauma (I have posted about this before).
Class III growth modification
There was some skeletal change with the use of protraction facemasks. This was a difference of 3.12 degrees of ANB. I think that this is clinically significant. (I have also posted about an excellent study that looked at the need for orthognathic surgery following protraction facemask treatment).
Correction of unilateral posterior crossbite
They found one study that suggested there was a high rate of crossbite correction from quad helix and expansion plates.
They found one study that looked at the effect of extraction of the primary canines on relieving developing lower incisor crowding. This showed that incisal irregularity reduced in both the control and extraction groups by 1.27 mm (SD=2.4) and 6.03 mm (SD 4.44). However, irregularity reduced in the extraction group at the expense of reduction in arch length.
Improved position of ectopic primary canines.
It was interesting that they did not find many trials on this area. They did mention a study on facemask protraction by Baccetti in which expansion with RME resulted in and increase of almost 50% in canine eruption. However, they could not analyse this data because of reporting issues.
They classified the quality of evidence of the studies as low to moderate using the GRADE approach.
What did I think?
This was a good systematic review in which they only included RCTs. I would recommend that all orthodontists should read this interesting paper.
As with all research, there are some issues that need to be addressed. For example, the authors point out that as these studies were done in university or hospital settings. As a result, they may not reflect international practice and may only represent secondary care provision. They also suggested that further trials are necessary to help answer this important question. I completely agree with their suggestions.
I think that it was also important that they did not find much evidence to support the provision of early treatment. Nevertheless, this leads me to consider whether “Absence of evidence, is evidence of absence of a treatment effect”? In other words, there may be an effect of treatment but we have not found it due to methodological issues. I am going to expand on this in a blog post later this week.
A way forwards?
This whole area of early provision of treatment is interesting and clinically important because it would be great if we could intercept the development of severe malocclusion. Nevertheless, we should also remember that all treatment comes at a price in terms of the associated risks and the additional cost to the patients. Furthermore, we have to consider whether it is more effective to wait until our patients are older and then solve their problems with one course of treatment.
In this respect, I found this case report on Facebook very interesting. It is clear that the orthodontist wants to illustrate his treatment and the comments made by other people are complimentary. We also need to remember that orthodontic philosophy is very different in the USA from other parts of the World. You can see that this patient had a developing crossbite and, what some would feel, normal incisor eruption with a midline diastema. In some countries operators would simply observe further development, in others the orthodontist may correct the posterior cross bite or ask a general dental practitioner to correct this problem, or as in this case a more extensive treatment was provided with Haas expansion, upper fixed appliance and two cephalograms. I have used this as an illustration to open a discussion on who is right and does this matter?
Finally, we can conclude that further research in this area is necessary. We can do this by running trials in specialist practice using outcomes that are relevant to our patients. These would be great orthodontic studies. I wonder if someone will do them or will we simply base our treatment on clinical experience, hearsay and Facebook?
Emeritus Professor of Orthodontics, University of Manchester, UK.