DOES THE ACCELEDENT AURA APPLIANCE SPEED UP THE INITIAL ALIGNMENT OF TEETH WITH BRACES?

This summary of my recent clinical trial published in the American Journal of Orthodontics & Dentofacial Orthopedics demonstrated no effect of the AcceleDent Aura vibrational appliance during the initial alignment of teeth with fixed appliances.

ALLERGIES, HABITS AND MALOCCLUSION IN YOUNG CHILDREN - WHAT HAPPENS OVER TIME?

Some clinicians advocate very early treatment in the primary (~ages 3-5) dentition and recommend interventions claiming they will prevent future orthodontic problems. But what if we did nothing and observed them? This very interesting article from Sweden followed 277 children from age 3 to age 11.5 and evaluated the presence of malocclusion, sucking habits, breathing problems, allergies and trauma over time.

There was quite a high prevalence of malocclusion at age 3 of 71% and although this improved by age 7 to 56%, it worsened again to 71% by age 11.5. However ~45% of subjects were considered in severe or moderate 'need' of treatment so ~55% had minor or no need. Many advocates of early treatment suggest intervention for open bites but interestingly this was one of the malocclusions that tended to self-correct as found by previous authors. Conversely deep bites did tend to worsen. As with previous studies trauma to the top front teeth was ~2.2 times more likely with increased protrusion/overjet.

Another re-emerging (previously in 1930's then 1960-70's) claim in orthodontics is the influence of habits and allergies on malocclusion and that early intervention is required to prevent adverse growth effects. This long-term observational study found sucking habits had little or no association with anterior open bite or posterior crossbite in the permanent dentition. As I have discussed in a previous Blog, many children stop the habits themselves as they get older and an open bite can improve spontaneously so treatment may not be indicated except in those that persist longer term.

Similarly allergies at age 3 had NO association with any future malocclusion at age 11.5. There are many good reasons for allergy, tonsil and adenoid treatments but to prevent abnormal facial growth is not one of them. I have personally had an ENT tell my wife that our 9 y.o. daughter (who suffers from allergies) required a turbinectomy otherwise she will undergo abnormal jaw growth - you can probably guess my response to that! My daughter has normal horizontal and vertical facial growth with mild crowding and although she will require some orthodontic treatment once all adult teeth have erupted for the mild crowding, her growth is proceeding just fine without the surgery. I feel sorry for those parents that do not have the knowledge of normal facial growth that I do as they may be 'scared' into having procedures for their children that they may otherwise think twice about. This article helps contribute to that knowledge so thanks to this Swedish team for following this group and presenting their findings.

Dr Peter Miles is the orthodontist at Newwave Orthodontics in Caloundra, Australia and teaches orthodontics part-time at the University of Queensland and is a visiting lecturer at Seton Hill University in the USA. Peter is one of the editors and authors of the orthodontic textbook, 'Evidence-Based Clinical Orthodontics'. Importantly, he has no financial interest in any products mentioned in these Blogs.

THE CVM METHOD AND THE IDEAL TIME FOR ORTHODONTIC TREATMENT.

The timing of treatment of Class II (protrusive top teeth &/or retruding lowers) patients has been debated for many years in orthodontics with some claiming you need to treat early, even as young as 5-8 (discussed in a previous Blog) or 9-10 or wait until 12-13! Several indicators have been used to assess the ideal timing and a more recent one is the Cervical Vertebral Maturation method (CVM) which uses the maturational stages of the cervical vertebrae in the neck on a cephalogram x-ray.

The CVM method was first developed by Don Lamparski along with Maria O'Reilly at the University of Pittsburgh where I trained and was later modified. However to be useful a method needs to be reliable and valid. One article demonstrated <50% intra-rater agreement (in other words less than half the time you agree with your own assessment). Another demonstrated that the CVM method offered no advantage over chronological age. Two recent papers concluded "CVM method could not accurately identify themandibular growth peak" or "...cannot predict craniofacial growth in girls with Class II malocclusion.". But let's say you do identify the ideal timing of treatment using the CVM method with the Herbst the study found ~1.9mm of advancement of Pogonion. However another study in adults (who are not growing) found they could still gain 1.3mm of advancement of Pogonion  so the ideal timing was only 0.6mm better and that is also assuming the change holds up long term which we know from other trials it doesn't.

The timing of orthodontic treatment is an interesting topic and really revolves around the issue of whether we can ‘modify growth’ of the mandible or not. Based upon the available quality scientific evidence it seems we can temporarily accelerate mandibular growth (Lysle Johnston’s ‘mortgage on growth’) but not achieve a significant long-term change and so the final outcome is mostly dento-alveolar/tooth movement. Studies supporting a change are retrospective in nature and/or use a historical control which is ~60 years old and not valid for comparison as trials using historical controls show larger treatment effects. In contrast the prospective RCT’s (UK, UNC, Florida) show no difference between treating early or in adolescence and this is supported by the Cochrane Review on the topic. The long-term ‘amount’ of change is similar regardless of the timing of treatment so it is more the ‘efficiency’ of the change/how quickly that is achieved that is affected by timing. Therefore the importance of determining the ideal timing of treatment with any method seems of minimal significance to the final outcome.

Finally I would like to thank Maria and all my other instructors at the Univ of Pittsburgh. I was so incredibly fortunate to have such wonderful mentors and friends.



Dr Peter Miles is the orthodontist at Newwave Orthodontics in Caloundra, Australia and was a part-time lecturer at the University of Queensland for 11 years and is a visiting lecturer at Seton Hill University in the USA. Peter is one of the editors and authors of the orthodontic textbook, 'Evidence-Based Clinical Orthodontics'.

PASSIVE SELF-LIGATING BRACKETS ARE BETTER - IT'S OBVIOUS?

This Blog topic was prompted by comments in Kevin O'Brien's excellent Blog regarding 'thinking about orthodontics'. Kevin was discussing evidence-based care and what we know versus what we don't know and how to apply our knowledge, skill and experience as clinicians in the treatment of our patients. Many suggestions were made about what we do and don't know but two comments in particular claimed that Passive Self-ligating (PSL) brackets were superior to conventional brackets during initial alignment in non-extraction treatment. I have also seen other claims in Facebook study clubs where the clinician states that in their experience, PSL brackets are superior for space closure in extraction cases (a future Blog topic). So is this evidence or their opinion and what is the evidence if any?

In 2006 I conducted the first prospective study comparing PSL brackets with conventional brackets in the lower arch in non-extraction cases. This was published in The Angle Orthodontist and I found that the PSL bracket was no better during initial alignment than a conventional bracket. Another non-extraction study published in the American Journal of Orthodontics in 2010 found there was no difference between PSL or Active SL brackets. Based upon this evidence in clinical trials this refutes the claim that PSL brackets are more effective in non-extraction cases during initial alignment. If we then include the evidence from extraction cases as well, this was summarised very nicely in another article in the American Journal of Orthodontics in 2014 where the data was plotted graphically (shown below) in a meta-analysis. The vertical line at zero ('0') represents no difference between brackets and the purple squares are the individual studies. What we are most interested in are the large green diamonds which represent the results combined together and as they overlap the zero line, this indicates there was no difference between any of the bracket types tested across the various studies during initial alignment. It seems the evidence is quite compelling that there is no advantage in PSL or ASL brackets over conventional brackets during initial alignment.

As the evidence clearly shows there is no difference between brackets, the choice of bracket then comes down to the personal preference of the clinician. BTW if you are interested in evidence-based orthodontics then I highly recommend subscribing to Kevin's Blog at http://kevinobrienorthoblog.com/

Dr Peter Miles is the orthodontist at Newwave Orthodontics in Caloundra, Australia and was a part-time lecturer at the University of Queensland for 11 years and is a visiting lecturer at Seton Hill University in the USA. Peter is one of the editors and authors of the orthodontic textbook, 'Evidence-Based Clinical Orthodontics'.