Fast Orthodontics - In Search of the Holy Grail

I recently wrote a review article in the Australian Dental Journal supplemental issue on accelerated orthodontic treatment. In it I discuss the many claims by manufacturers of several appliances and proponents of various techniques that claim to accelerate treatment. This appeals to both the patient’s and the clinician’s desire to ‘speed’ up and shorten their treatment, however how strong is the evidence or is it just marketing hype? I am a little concerned as it would appear that in some respects, advertising claims in orthodontics are following down the path of the exercise fads claiming rapid results with little or no effort - I certainly find some effort and restraint is required :-). Mechanically and biologically, many of the claims of accelerating orthodontic treatment just do not make sense (such as with self-ligating brackets which I have written about before) or are quite invasive and/or expensive (some of the surgical techniques are ~$5000 and the effect lasts only ~3 months). This is discussed in more detail in the article.

One of the clinical trials I have been conducting in our office on vibration and accelerated treatment was also published recently in the American Journal of Orthodontics and Dentofacial Orthopedics and I was asked to produce a short video on that article which can be found here.

This was included in the review article I wrote also. More recently we have just analysed the data on the 2nd part of this ongoing RCT when closing extraction spaces and I also found that there was no clinically or statistically significant difference in the rate of space closure – in other words, vibration had no effect. This is important for patient’s to be aware of as they can be asked to spend $500 - $1000 for various appliances which may have minimal or no effect. The problem with emerging techniques and methodologies is that there may be no trials examining their performance so we must then rely on our knowledge of biology and mechanics on whether we consider it ‘may’ have a positive effect or not. However, if we are unsure, then patient’s should be informed of this until research exists. They can then decide if they will gamble on the appliance/technique possibly working or stay with the current approach. So the Holy Grail of accelerated orthodontic treatment seems elusive and the honest answer about the various options to patients is ”There are many techniques and appliances claiming to accelerate orthodontic treatment but the current evidence is poor and some have been shown to have no effect”.

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'.

HIGHEST VIEWED BLOGS SO FAR!!

For this Blog I thought I would recap the 5 most popular Blogs I have published so far and it is interesting to note that they are all related to early #orthodontic treatment. Although some of these involve the same topic I will rank them in order of the most viewed individual Blogs. Note the text in a different colour is a link to the original Blog or document so just click on it if you wish to know more.

1) The most read and searched Blog and also one of the more recent was 'Maxillary Expansion - Unexpected Benefits?' in September this year. This Blog has interest for readers who are clinicians as well as the general public discussing #expansion and its possible effect upon bed-wetting, sleep #apnea and middle ear problems. Expansion is a common procedure in orthodontics but there is limited quality research on these specific areas. It is also an emerging topic with a lot of mis-information accessible on search-engines and deserves more well-designed research in the future.

2) On a similarly related topic was this Blog back in January 2015 titled 'Do Orthodontic Extractions Cause Sleep Apnea?'. Again it is a controversial and emerging subject with a lot of mis-information which is easy to disseminate when there is minimal research. I am glad these two topics have received such an enthusiastic response.

3 - 5) The next three topics all related to #Myofunctional appliances. In order these Blogs were 'More on Myofunctionals - 2 Clinical Trials' followed by the first of the Blogs on this topic, 'Myofunctional Appliances - What's the Evidence?'. The third and most recent of the Blogs on this topic was also the most recent Blog prior to this and reported the 'Results of a RCT of a Prefabricated Functional Appliance'. This is an area dominated on search engines by companies and clinicians extolling the virtues of these appliances and treatment approach. The higher levels of evidence come from clinical trials which are discussed in these Blogs and although these trials are not ideal they currently are the best level of evidence we have and come to a similar conclusion. Although they find statistical differences, these differences were quite small and indicated that these appliances were less effective than more conventional treatments for bite correction. Despite being in an evidence-based era where we would like to see well-conducted clinical trials upon which to base our treatments, there is limited quality research and both clinicians and the general public need to be wary of the claims being made until well designed research is available.

I would like to thank you the reader for your interest as my goal throughout is to provide quality information for clinicians and the general public on the more controversial topics in orthodontics. I would also like to point out that I have no financial interest in any appliance or technique I discuss in these Blogs so when gathering information, consider whether the source of information is potentially biased and associated with that particular appliance or technique.

Remember any of the Blogs can be found at http://newwaveorthodontics.blogspot.com.au/ and scrolling down and older ones can be accessed at the bottom of the page by clicking 'older posts'. Wishing all a happy, safe & prosperous 2016.

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'.

RESULTS OF A RCT OF A PREFABRICATED FUNCTIONAL APPLIANCE - MYOBRACE

One of the most popular topics in my series of Blogs has been on prefabricated #Myofunctional appliances and so I thought I would share the results of this randomized clinical trial from Sweden which was presented at the recent 8th International Orthodontic Congress in London. The complete abstract is below and follows on from their paper reported at the 7th IOC in Sydney in 2010 which I reported here.

The conclusions reinforce that the overjet/protrusion correction obtained with the prefabricated Myobrace was dental/tipping of teeth while the custom made #Activator appliance achieved a better molar correction, however compliance with both appliances was poor. This will affect the clinical choice of an appliance as in cases where simple tipping may be suitable then the cheaper prefabricated appliance may be appropriate. However if more molar bite correction is required then the custom-made appliance would be more suited.... as long as they wear it. The percentage of subjects in this study having unsuccessful treatment was very high at 70% with the Myobrace appliance and ~53% with the Activator which the authors attributed mainly to a lack of compliance. The patient and the family should therefore be involved in the appliance choice or alternatively appliances that do not require as much cooperation can be used (the subject of a future Blog). These authors are to be congratulated on a job well done in conducting this trial.

Update: The full paper is now available in the European Journal of Orthodontics.

Authors

E. Cirgic, K. Hansen, H. Kjellberg.

Abstract:

TREATMENT EFFICACY OF PREFABRICATED FUNCTIONAL APPLIANCES AND ANDRESEN ACTIVATORS IN CLASS II, DIVISION1 CASES: A RANDOMIZED CLINICAL TRIAL

Aim: The purpose of this study was to compare the clinical effectiveness in reducing large overjet between a prefabricated functional appliance (PFA) and a slightly modified Andresen activator (AA). Methods: A multicentre, prospective and randomized clinical trial was conducted in 12 general dental practices and an ethical committee approved the study. The sample consisted of 97 subjects (44 girls, 53 boys) mean age 10.3 years with a Class II, division 1 malocclusion and an overjet ≥ 6 mm. The study was designed as intention to treat and the patients were randomly selected to treatment with either a PFA or a AA. The PFA and AA group consisted of 57 subjects (28 girls, 29 boys) and 40 subjects (16 girls, 24 boys) respectively. Overjet, overbite, lip seal and sagittal relation were recorded before and at 3, 6 and 12 months after start of treatment. The endpoint of treatment was set to overjet ≤ 3mm and after this a 6 months retention period followed. Results: No significant difference was found in overjet, overbite and lip seal between the two groups. Significant difference was found in sagittal molar correction between the two groups. The treatment of 40 patients with PFA and 21 with AA were considered unsuccessful mainly due to poor compliance. Conclusions: Prefabricated functional appliances are as effective as Andresen activators in correcting overjet, overbite and lip seal. Andresen activators seem to be more effective in sagittal molar correction than PFA. The success rate in treatment with both appliances is however, low.

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'.

MAXILLARY EXPANSION - UNEXPECTED BENEFITS?

Maxillary expansion is a relatively common procedure in orthodontic treatment for bite correction and I have Blogged previously about it for the correction of crossbite as well as its use in creating space. However, expansion has also been showing some unexpected benefits for some patients in other areas which I will discuss in this Blog.

Expansion of the upper jaw is most effective in pre-pubertal children when the midline suture is still responsive and the surrounding bones are more malleable. As the maxilla (upper jaw) forms the floor of the nasal airway and supports the soft tissues of the nose, this expansion has been suggested to improve a constricted or congested airway. Much of this was anecdotal as improvements can occur coincidentally or with time and not necessarily be related to the procedure. This is why research in the form of clinical trials is important to try to reduce the biases inherent in simply observing something. However there is a growing body of evidence of the potential beneficial effects of maxillary expansion beyond the correction of dental crossbites.

Expansion and Nocturnal Enuresis/Bed-wetting:
In the 1990's some research suggested that expansion of the upper jaw may help reduce nocturnal enuresis or bed-wetting in children. More recent studies agreed with these findings showing significant reductions (~75%) in the number of nights of bed-wetting following expansion with ~30% were completely dry at night after expansion. This was even in the absence of a pre-existing crossbite. Suggested reasons for this improvement relate to an indirect effect on the pituitary gland or an improvement in the airway with expansion which may help with a possible association between enuresis and sleep disordered breathing in children.

Expansion, Congestion, Sleep Apnoea:
One of the above papers also found that nasal airflow increased while nasal resistance to airflow decreased. Earlier research by Peter Vig in the 1980's found that rapid maxillary expansion resulted in a significant reduction in nasal resistance but there was considerable variation and so the outcome was not predictable. Other research has shown this reduction remained a year later. Another paper found those with the highest initial nasal resistance tended to obtain the greatest benefit from expansion with the greatest reduction in nasal resistance.

Maxillary expansion has also been suggested to improve obstructive sleep apnoea or apnea in children (where the child stops breathing several times per hour of sleep). I have discussed extractions and sleep apnoea previously. Studies have found expansion can result in a significant reduction in the numbers of episodes of apnea in children including those with enlarged tonsils and adenoids. Although the response is unpredictable the results are promising enough to warrant more comprehensive clinical trials and to be considered as a treatment strategy especially when there are other reasons to consider maxillary expansion.

Expansion and the Middle Ear:
In studies on patients with narrow arches and conductive hearing loss it has been found that rapid and semi-rapid expansion of the maxilla resulted in an improvement in hearing and eustachian tube function and these improvements held up for 3/4 of the subjects up to 2 years later. However these are children with narrow jaws so the same may or may not hold for those with normal or wide arches.


Summary
So it seems that maxillary expansion may have benefits beyond correcting crossbites and creating some space. However it must be kept in mind these studies are not definitive and the outcomes are not guaranteed so more research in the form of randomised clinical trials is indicated. For this reason expansion may be suggested when it is indicated for other reasons or in consultation between your medical practitioner/sleep physician/Otolaryngologist (ENT) and your orthodontist.


I would like to thank Dr James Noble (Orthodontist - Toronto) for his feedback on this Blog topic.

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'.