Root resorption and orthodontics

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

JCO, Miniscrew Loosening, Prof B.Melsen

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.

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

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.

DIOSPORT

Diosport is an intraoral device that serves to restore the muscle balance of the body and thus allow the athlete to develop their true high performance.

This device works by decompression and reposition of the mandible by means of high-tech electronic mandibular deprogramming, objective measurement of masticatory muscles using surface electromyography and mandibular kinetography.

In conclusion, the stability is achieved by repositioning the jaw, allowing the muscle chains to operate in perfect harmony and increasing the airway providing better oxygenation.

For those interested in this subject I recommend to search for publications in the website of Diosport

http://diosport.com.br

N.S.D.

Rheumatology Journal, 50 volumes celebration, key articles free access.

The Rheumatology journal, from Oxford Press, is celebrating with the current issue 50 volumes of the journal. The journal has been around since 1952. You can read further at the editorial of the current issue.

The editors of the journal have chosen an interesting number of papers which are characterized as "key articles" and are given free access for readers interested. You can find the list here.

Among those articles, "A simplified disease activity index for rheumatoid arthritis for use in clinical practice"

For the orthodontic world, rheumatoid arthritis and especially juvenile idiopathic, is of major interest. Some of those young patients either with oligo- or poly-arthritis, systemic or not, can have their first symptoms at the TMJ and the dentist or orthodontist might be the one to suspect and help to the diagnosis of the disease.

As such those interested in the field could go through the articles that the experts are referring as key articles on the subject, for a quick overview and update of the current knowledge and treatment approach.

D.G.

The stability of miniscrew placement, Editor's Corner, JCO Jan 2011

The Journal of Clinical Orthodontics published the results of an ongoing survey concerning the failure rate and the factors that are influencing the stability of miniscrew placement.


A wide number of editor contributors of the journal, and some widely known clinicians were given the above question. In other terms what is, in their clinical experience, that matters for the stability of miniscrews.


A number of factors were mentioned:

• Experience of the operator
• Primary stability - Stable insertion
• Self drilling mini-screws
• Loading perpendicular to the long axis of the tooth and avoiding unscrewing moments
• Quality and thickness of cortical bone, along with wise insertion site selection
• Avoidance of root proximity

A wide range of failure rate was suggested, from 5% up to 20% by other clinicians. The whole pdf can be downloaded for free at this link

A Closer Look at Stem Cell Treatments

The International Society of Stem Cell Treatments launches a new website to shed some light on the stem cell treatments available right now. The website is called "a closer look at stem cell treatments", and this is the link: 

• http://www.closerlookatstemcells.org/

After the society 8th annual meeting on the 16-19 of June, a review of the status quo right now worldwide on stem cells is attempted through this new website. 

• 10 most frequent questions on stem cell treatments
• types of stem cells
• how clinical trials work

Are only a few of the information that can be found on this new website. Stem cells are of great interest in the field of orthodontics and dentistry for the future of restorations and transplantations of dental tissue, and it is thus worth a closer look, for the options that arise for the clinician.

Cell Homing, Regeneration of Pulp Like Tissue in Root Canal Treated Human Teeth.

Lately there has been articles and posts around dental blogs, with pictures of this tooth shape scaffold.


From the University of Columbia Dr. Jeremy Mao et all have published an article in May 2010. On this article root canal treated, real size human teeth are transplanted to the dorsum of mouses and were injected on the internal dentin surface of the root canal treated teeth with human bone marrow stem cells, and growth factors (VEGF and/or bFGF) and nerve growth factors (NGF)

Angle Classification Today, and Post-treatment Stability.

Edward Angle is considered the father of modern orthodontics. He classified malocclusions by the relationship of the mesio-buccal cusp of the upper first molar and the mesio-buccal groove of the lower first molar.

• Class I: When the mesio-buccal cusp of the upper molar sits in the mesio-buccal groove of the lower first molar.
• Class II: When the upper molar cusp is placed anteriorly and there is an overjet (div1) or there is a compensatory retroclination of the upper incisors (div 2)
• Class III When the lower molar is anteriorly displaced, with or without a negative overjet (mandibular prognathy or maxillary retrognathism)