Orthodontic Corner

Interceptive approach of future palatally displaced canines, by an early extraction of the deciduous canines.

2014-01-08T23:25:00.000+01:00

Very interesting and clinically significant article at the latest issue of the Angle Orthodontist:

Conclusion:
"The extraction of the deciduous canine is an effective measure in PDC cases, but it must be done in younger patients in combination with early diagnosis, at the age of 10–11 years. Maintenance of the perimeter of the upper arch is an important step during the observation period, and a palatal arch as a space-holding device is recommended"

I would add that removable retention with a plate (Hawlley, Begg retainer, Jensen plate etc), or let's say an MRC trainer could also do the trick! Other than that please take the time to read this article over the Angle's website:

LINK HERE

Kind regards,

D.G.

Introducing the New AJO-DO's iPad Application.

2014-01-02T18:08:00.002+01:00

The new application for tablets is out from the American Journal of Orthodontics and Orofacial Orthopedics.

Access all new and old issues and articles, along with integration with iBooks, dropbox and many more.

Worth downloading if you own a tablet:

- iTunes link
- Alternative from Elsevier Advanced Health application

D.G.

Happy new year 2014!

2014-01-01T05:50:00.000+01:00

Wishing you all a happy new year, 2014.

Productive, healthy and peaceful!

D.G.

Clinical Key, Search Engine by Elsevier.

2013-12-12T23:48:00.001+01:00

I admit that I did not know of it's existence till now.

Clinical key is a specialised search engine for clinicians in the medical field.

Try it out it is quite good!

https://www.clinicalkey.com

D.G.

Interlabial gap behavior with time, JWFO

2013-12-02T19:51:00.000+01:00

An interesting article is in press at the Journal of the World Federation of Orthodontists JWFO

The article aims to clarify wether the interlabial gap (shown as number 2 on the tracing to the left) reduction over time can be associated with the treatment therapy that was chosen.

62 Class I and Class II patients (with lip incompetence) were treated with or without extractions, and the gap was measured before, after and at the long term follow up.

What was found is that the interlabial gap decreases significantly more at the extraction therapy group compared to the non-extraction one. This happens during treatment.

During retention however, non-extraction group has a greater decrease of the gap, when compared to the extraction therapy group.

Also the authors show that variables such as lip length are associated with the amount of interlabial gap but NOT the decrease during treatment and over-time. The later has to do with the treatment chosen, and of course normal aging.

In plain words the decrease of interlabial gap during treatment at the extraction therapy group happens faster, and that is why during retention there is a smaller decrease when compared to the non-extraction therapy. "Aging faster?!"

The article can be found here: http://www.jwfo.org/article/S2212-4438(13)00056-8/abstract

7-9 February 2014, Winter Conference of the AAO, Las Vegas.

2013-10-27T17:02:00.003+01:00

This year's Winter Conference of the AAO, is about Adult Treatment, and it sets out to bring closer Orthodontists and Restorative dentists, in favor of patients.

Adult patients interdisciplinary approach was late AJODO editor's Dr Vince Kokich favorite topic.

A topic he contributed to vigorously throughout his professional career and as such this meeting will be dedicated to him.

Ravindra Nanda and Dirk Weinchmann are just a few of the many names lecturing this year.

This is the link for downloading the program pdf

The online registration is open

D.G.

Comparison of Untreated and Treated Subjects, Occlusal Changes.

2012-07-30T10:07:00.000+02:00

Post-Treatment and Physiologic Occlusal Changes Comparison. TheAngleOrthodontist, early online access.

The article compares the occlusal changes during retention of (PAR and Little indexes):

97 cases 4 premolar extraction cases and
58 non extraction cases, versus
114 untreated subjects.

What was found is that:

The treated groups showed more changes according to PAR and Little maxillary indexes than the untreated group in the observation period.
The post-treatment change of the mandibular anterior crowding of the treated extraction group was greater than the mandibular crowding caused by physiologic changes in the untreated group.

An article is published at the European Journal of Orthodontics, from a Finish group, "Dental arch width, overbite, and overjet in a Finnish population with normal occlusion between the ages of 7 and 32 years"

In this article there is a series of dental casts of Class I, Untreated Subjects, been analyzed:

18 women and 15 men
at age 7, 10, 12, 15 and 32 years old

What was found is that:

Both arches at canine and molar region increase from 7-15 and decrease from 15-32 years of age.
Overjet and overbite changes are also noted from 15-32 years, as well as attrition and tooth wear that plays a role to the above mentioned occlusal changes.

Discussion:

Physiological changes in the occlusion is a major subject, that even though there are some very important studies been published in the past, we still do not know that much about.

It should be mentioned strongly to our patients that your dentition and your soft tissue for that matter WILL deteriorate with age, and whenever it is possible the orthodontist should be in doubt of what he/she sees and how it is explained to the patient.

An example could be of course secondary mandibular crowding and the role of wisdom teeth eruption which is so effortlessly blamed by the orthodontist to be the cause of this crowding development. When we know or should know that canine width DOES decrease with age, especially in the lower jaw and that the contact points become surfaces (are worn out) and teeth tend to slowly migrate mesial with age...

Suggested previous literature:

Sinclair PM, Little RM. Maturation of untreated normal occlusions. Am J Orthod. 1983;83:114– 123.
Thilander B. Orthodontic relapse versus natural develop- ment. Am J Orthod Dentofacial Orthop. 2000;117:562–563.
Al Yami EA, Kuijpers-Jagtman AM, van’t Hof MA. Stability of orthodontic treatment outcome: follow-up until 10 years postretention. Am J Orthod Dentofacial Orthop. 1999;115: 300–304.
Bishara S E, Jakobsen J R, Treder J, Nowak A 1997 Arch width changes from 6 weeks to 45 years of age. American Journal of Orthodontics and and Dentofacial Orthopedics 111: 401–409
Henrikson J, Persson M, Thilander B 2001 Long-term stability of dental arch form in Norman occlusion from 13 to 31 years of age. European Journal of Orthodontics 23: 51–61
Thilander B 2009 Dentoalveolar development in subjects with normal occlusion. A longitudinal study between the ages of 5 and 31 years. European Journal of orthodontics 31: 109–120

D.G.

Mini-screws is just a tool among others!

2012-07-04T17:35:00.000+02:00

With Dr. Kokich at the EOS 2012

Driven from the recent editorial article of Dr. Kokich at the AJODO, I would like to emphasize what this article was all about.

TADs have been around for some time now in the orthodontic field, and have changed the approach we follow at a number of cases.

This is all wonderful but we should also remember that mini-screws are just a tool among others.
What is really important is correct diagnosis, individualized treatment planning and well designed biomechanics applied to the right patient.

PURE intrusion of anterior and/or posterior teeth for example, is a tooth movement that can be achieved ONLY when the reacting force is not applied to the dentition. A clean way of doing that is bone anchorage.

However we don't want to intrude the anterior too much especially when treating adolescence, where a gummy smile of 4mm IS very normal for their age!
Let alone the issue of muscle adaptation when intruding posterior teeth and altering the vertical height of open bite patients...

It feels good to read what I was taught in Aarhus, been repeated by someone like Dr. Kokich and at the AJODO, because unfortunately when you say these things to a group of fellow orthodontists, people tend to look at you a bit strange. Marketing you see...

Thank you ;)

p.s. Here you can find the pdf of the AJODO Editorial

D.G.

Clustering In Orthodontic Trials

2012-05-30T11:53:00.002+02:00

Long time no see! I was very much pre-occupied with the change of my professional career. I have moved back to Crete and set up my private office which is a few months now ready and working (http://www.orthocorner.com). The web site is mainly in Greek for now as I am creating it myself both design and content so it takes time.

Now to our subject, clustering in orthodontic trials:

First of all clustering is mainly when there are several measurements are taken from the same individual, e.g. measuring inclination of different teeth at the same jaw...
The issue here is that those measurements are not independent and "might" have similarities due to the fact that it is the same subject with individual factors that apply to all those teeth (of the above example).
As such, this has to be taken to account when calculating the sample size for example, and more-over in deciding what kind of statistical analysis of the data gathered, will be performed to reach safer and more useful conclusions.

I will not get into any further detail in order not to bore you, but whoever is interested in reading a bit more about this very interesting and so widely talked about subject there are two articles at the online early of the European Journal of Orthodontics:

p.s. Do not forget the EOS this June at beautiful Santiago de Compostela, Spain

D.G.

Management of unilaterally deep impacted first, second, and third mandibular molars.

2011-10-16T19:57:00.000+02:00

This is indeed a difficult and rare case of deeply impacted 1st mandibular molar, treated to a very satisfactory result, by finally uprighting the 2nd mandibular molar and extracting the 1st one. In addition one upper premolar on the same side was extracted in order to move the upper midline on to the facial.

Initial panoramic view

Final result

Read the case presentation at the Angle Orthodontist

D.G.

Root resorption and orthodontics

2011-09-20T15:07:00.000+02:00

A Swedish prospective clinical trial (Gothenburg), of 152 orthodontic patients, is published at the current issue of The Angle Orthodontist. The study is performed on CBCT data collected at baseline, 6-months in treatment, and treatment finish.

CBCT allows for differentiation of the exact root surface that has been resorbed, such as lingual/palatal, buccal, or mesio-distal. This cannot be differentiated by conventional 2D radiographs.

A case of severe root resorption

As expected up to 91% of all teeth showed some degree of root shortening.
7% of the sample had at least one tooth with more than 4mm of root shortening (however no more than 3 of those teeth per patient)
The root shortening rate/month, was significantly larger for the period after the 6 months in treatment when compared to the first months.
The upper dentition was affected more than the lower.
Lastly, the palatal surface of the upper centrals and laterals was the most affected region (that could be associated with the compression of those regions when torquing moments, or intrusional forces are applied at the bracket level)

Here is the link to the original article.

D.G.

Academic Orthodontic Opportunities, USA

2011-09-05T14:13:00.001+02:00

Academic positions listing in the US, for those interested...

Taken from the Angle Orthodontist, you can download the PDF here

Twin Block, with or without upper labial bow? Angle Orthod, ahead of print.

2011-08-28T17:45:00.000+02:00

One of the most read posts of this blog, is the recent W.Clark article at the JO. The Twin Block is a widely used functional appliance, and its creator advocates that his 30 years experience has taught him, that there is no need for a facial bow at the upper plate of the appliance.

A group of scientists from King's College university, have performed a RCT, to test the above hypothesis. What they find is that indeed the use or not of a facial bow at the upper plate of the twin block, does not seem to influence significantly the treatment results.

Construction of the Twin Block with and without a facial bow.

For further information please refer to the ahead of print of The Angle Orthodontist, at this link

D.G.

Anterior open bite and tongue positions, DPJO

2011-08-03T13:14:00.001+02:00

A very interesting article can be found at the current issue of the Brazilian journal. The anterior open bite patients are among the hardest ones to treat, and the most common complication is the relapse of the treatment result even after complete closure of the open bite.

By looking a little more into the reason that created the malocclusion we can try to enhance our treatment results. The equilibrium theory is know from Proffit, and from studies of researchers like Thüer in the 80ies. It is according to those beliefs that the equilibrium between the tongue function and position, and the lips assures a perfect inter-incisal angle and stability at the front region.

Take a look at this scheme of different tongue positions, taken from the article:

The first one is the normal position of the tongue, showing the forces exerted upon swallowing.

This is how it may look when a high tongue position is established.

This is how it may look when a horizontal tongue position is established.

Now why is it important to differentiate between those positions?

-Well, obviously because there are different approaches to treat depending on where the tongue position is and how we are going to try and change it.

There is one small point to be made regarding the change of tongue position. That is that it is extremely difficult to alter the tongue function permanently (for some researchers this is not possible). Very impressive results have been shown by many clinicians (first and foremost it was Dr. Frankel) but unfortunately the treatments needed are long, and quite often those patients relapse again to an open bite.

That been said, please have a look at the link of the article at the Brazilian journal, it is definitely worth the read:

Link to the pdf of the article.

D.G.

JCO, Miniscrew Loosening, Prof B.Melsen

2011-07-31T12:13:00.001+02:00

Prof. B. Melsen talks in simple words about miniscrews and the reasons behind failure.
First of all the failure of miniscrews can be seen immediately (in the first couple of weeks) or later.

A summary of some of the points given in this article:

Early Failure:

Insufficient primary stability (wrong site selection, due to insufficient bone quality, or quantity)
Iatrogenic failures (jiggling during the insertion, over-screwing)
Magnitude and direction of the force loading (high magnitude of force, it is advised to start with around 50cN and increase the force gradually, also unscrewing moments should be avoided)

Later Failure:

Change of the local environment (inflammation due to root proximity, or change of the local bone turn over, e.g. in relation to resorption of the root of a deciduous tooth)
Systemic factors (such as smoking, alcoholism, and medication that influences bone turnover have been proven risk factors for implant failure in general)

In any case when a miniscrew fails, the new insertion site has to further away from the old one, at least twice the diameter of the screw. In addition choosing to change the site and use the screw with an indirect loading instead of direct could be advised if a screw fails more than once at the same patient.

This is the link of Prof B. Melsen's article at the current issue of the JCO.

References:
Clinical Guide
Clinical Applications

D.G.

Hebrew University-Hadassah Orthodontic Program

2011-07-25T15:00:00.005+02:00

For those interested, please take advantage of the time left for submitting applications for the IPOP (International Postgraduate Orthodontic Program) in Hadassah School of Dental Medicine in Israel. The deadline is the 31st of August 2011.

Being a Postgraduate Student in Orthodontics at TAU (Tel Aviv University) I am aware of the high level of education offered in Israel. For this reason, and as Ambassador of EPSOS (European Postgraduate Students Orthodontic Society) for ISRAEL, I advice all the European Dental Students interested in Orthodontics to apply to this 3 year Orthodontic Residency Program in Hadassah School of Dental Medicine in Jerusalem.

Nuno Sousa Dias

Prevalence and severity of vestibular recession in mandibular incisors after orthodontic treatment.

2011-07-18T18:27:00.003+02:00

An interesting large sample, retrospective study can be found at the "ahead of print" at the Angle Orthodontist website.
The study is from Oslo University, Norway, and it is a collaboration of the perio and orthodontic departments.
A sample of 588 patients was analyzed, with intraoral photos, plaque accumulation, inflammation, and cephalometric measurements (A-Pog, Incisors inclination, ML-NSL, NL-NSL) regarding the mandibular incisors recessions. The Miller classification was used.

Conclusions:

10,3% of the cases were found with recessions: 8,6% Miller Class I and 1,7% Miller Class II. That is not a very large prevalence.
In the presence of gingival recession, retroclination of the mandibular incisors in cases of mesial basal relation (Angle Class III) seems to increase the risk of a more severe gingival recession.
Keeping the gingiva in the mandibular frontal area as healthy as possible during orthodontic treatment appears to be the determinant in the development of gingival recession. Inflammation seems to be a contributory factor for this condition. A careful examination of the buccal gingiva in the lower incisors, before deciding the amount of movement of these teeth, seems important.

Link of the study

D.G.

Upper bonded retainer failures, AngO ahead of print

2011-07-09T20:30:00.006+02:00

The Angle Orthodontist, at it's online ahead of print, has published an interesting retrospective study of Dr Sabine Ruf of Giessen University, Germany.

466 consecutive upper bonded retainers were checked and surprisingly a 58.2% of the patients experienced failures of their retainer.

Click to enlarge

Now that's plain a lot. Looking at the graph above:

The retainers that fail at the first 6 months are due to detachments. The incidents of detachment reduce over-time.
The complete loss of the retainer has more or less the same probability of happening over-time.
Lastly the fracture of the retainer, as expected is something that happens more often after a year or two.

Abstract link

D.G.

Cite while you write, in Apple, Pages (iWork 09) with Endnote

2011-07-09T12:46:00.001+02:00

When I started my thesis I wanted to write it in Pages (iWorks 09). The university librarian initially told me that it was not possible to cite and write natively with the Mac's iWorks suite. However we soon found out that you actually can.
Having finished writing without using Microsoft Word at all I would like to share a small video for all those Mac people who would like to know how to write scientific papers in Pages. If I might say it works pretty smooth, and it is quite versatile as you can see at the following:

D.G.

Force extension relaxation of medium force orthodontic latex elastics, AngO June 2011, early access

2011-06-28T19:30:00.001+02:00

The Angle Orthodontist of June 2011, has a very interesting article concerning the forces of latex elastics, over time.
The elastics is one of the few tools so widely used and so little studied in orthodontics.

The graph on the left shows for three commercial latex elastics, that for the first 3 hours there is a decrease of force.
This force increases for the next 3-6 hours and decreases again up to 12 hours of stretching.

The link of the article which is ahead of print (early online access for those subscribed to the journal).

The study was made, with continuous loading of several latex elastics of three different companies. The stretching was performed for 24hours and the elastics were embedded in saliva at mouth temperature during those 24 hours.

Reference:
Force extension relaxation of medium force orthodontic latex elastics
Daniel J. Fernandes^a, Gisele M. A. Fernandes^b, Flavia Artese^c, Carlos N. Elias^d, and Alvaro M. Mendes^c

D.G.

Birte Melsen: How has the spectrum of orthodontics changed over the past decades?

2011-06-26T14:34:00.001+02:00

The Journal of Orthodontics of this month has invited Prof. DrOdont, B.Melsen from the university of Aarhus Denmark, to write an article about orthodontics today.

This article is in a form of a lecture. Dr. Melsen talks about almost every aspect of orthodontics today.

From "fast food orthodontics", self-ligating, "intelligent wires and brackets", "no bending orthodontics" to individualized treatments for adults with periodontal and degenerative diseases. TADs and digital orthodontics (digital casts, computerized treatment planing) are a field of interest for the future, and push the limits of orthodontics according to Prof Melsen.

Along the caustic comments about the industry, the marketing of new wires and brackets, it is reminded to everyone, that orthodontics is all about treatment planning and goals orientation. There is no cook book in orthodontics, and this article is certainly worth of your time.

A short abstract of the article follows:
"Three aspects have had a significant impact on orthodontics during the last few decades: the appliances being used, the anchorage being used and finally the distribution of patients being treated.

Firstly, the marketing of appliances is increasingly leading the orthodontist to outsource important aspects of treatment such as wirebending and bracket positioning. Brackets and wires are being presented as the solution to all problems and metaphysical terms such as ‘intelligent design,’ ‘working brackets’ and ‘intelligent wires’ are dominating advertising and reducing the impact of evidence-based treatment approaches.

Secondly, the introduction of skeletal anchorage has potentially widened the spectrum of orthodontics, allowing for treatments that could not be done with conventional appliances. Biomechanical knowledge is, however, mandatory if we agree that the system should not be abused.

Thirdly, the orthodontic population comprises an increasing number of adult patients, many of whom are characterized by a degenerated dentition. The treatment of these patients requires a thorough knowledge not only of biomechanics but also of the reaction of the periodontal tissues to various types of loading. They can be treated only with custom-made appliances adapting the force systems and magnitude to the patient-specific treatment goal.

In summary, the orthodontic world is being split between ‘appliance-driven fast-food orthodontics’ where the results to a large extent are dependent on both growth and function and ‘orthodontist-driven’ ‘slow-food’ treatments attempting to push the limits of the possible in relation to complicated problems and reversal of degeneration in adult patients. The latter treatments are performed with individualized appliances adapting the force system to the patient.

prof, DrOdont, DDS, Birte Melsen"

D.G.

Growth Charts, 5-20 Years of Age

2011-06-16T22:43:00.003+02:00

Another short post of an iPhone, iPad app. Growth charts of an unlimited number of patients, height, weight, BMI. Those charts can be valuable for the orthodontist to analyze the growth before and during dentofacial orthopedic treatments.
The application uses the database of the World Health Organization (WHO) for 5-19 years of age, with separate charts as well of 5-10, 10-15 and 15-19 years for further analysis.

A screenshot (height for age 5-10):

iTunes link

D.G.

p.s. We have 3 promotional codes for this app. For those interested post a comment below.

Dental Prescriber, iPhone app

2011-06-14T21:19:00.000+02:00

Just a short post for an interesting application I found at the app store for iPhone. It is a prescriber application tailored to the needs of the general dentist.

A screenshot:

iTunes Link

D.G.

Gnathology

2011-06-11T15:51:00.007+02:00

For those of you interested in Gnathology here is an opportunity to assist a fantastic scientific program organized by the International Academy of Gnathology – American Section in an outstanding location (San Antonio, Texas).

Some of the most relevant presentations for orthodontists are presented bellow:

Dr. Barry Glassman – Allentown, Pennsylvania

Functional diagnosis of the TMJs using joint vibration analysis

Dr. Mariano Rocabado – Santiago, Chile

The craniovertebral centric relation concept, synovial TMJs, and occlusal prevention

Dr. Larry Wolford – Dallas, Texas

Examination, diagnosis and treatment of retrognathic mandibles with TMJ derangements

Dr. Ron Verrett – San Antonio, Texas

An update on oral appliances in the treatment of sleep apnea

Dr. Markus V. Troeltzsch – Ansbach, Germany

Stomatognathic Etiologies of Headache and their Treatment

For more information please visit the website

http://www.gnathologyusa.org/

N.S.D.

OrthoVoice 2011

2011-06-02T17:13:00.000+02:00

The OrthoVoice meeting, as shown above, happens this year October 20-22 at the Planet Hollywood Resort & Casino in Las Vegas. The meeting has some interesting keynotes starting Dr William Profit, Dr. M.Apern, Dr. R.Scholz and many more. Here's a link of the schedule.

For those interested for a clinical and practice management meeting, mark your calendar.

D.G.