Age is not a restrictive limit but proper diagnosis Based on mandibular position and condiles relationship is fundamental

Effectiveness of functional appliances when indicated is seen on the basis of peak pubertal growth status analysed on the basis of skeletal maturity indicators like CVMI and MP3. Normally this period is around 13 years in girls and 14 years in boys in our clinical practice

This is an interesting question, but there is no consensus on the definition of a "functional appliance" (Singh, 2010). Furthermore, there is a lack of information on the mechanisms by which 'functional' appliances achieve their (undoubted) outcomes (Singh, 2004). However, the use of 'functional' appliances has more recently been applied to older patients for a different reason, using a different name i.e. the use of mandibular advancements appliances (MADs) for the management of obstructive sleep apnea. Unfortunately (in this case) a significant number of adults present with late onset mandibular protrusion, presumably due to continued condylar proliferation, at least in part, resulting in a derangement of the occlusion and temporo-mandibular joint issues. At the Asia-Pacific Orthodontic Congress (Dec 2012) and at the recent meeting of the International Association for Orthodontics (March, 2013), we presented our findings of increased Maxillary bone volume in adults, using a "biomimetic" appliance to help re-coordinate maxillo-mandibular spatial relations. We were awarded a prize for this work, which will be appearing in an Orthodontic journal in their next issue (Singh et al., 2014; in press).

Singh GD. On Growth and Treatment: the Spatial Matrix hypothesis. In: Growth and treatment: A meeting of the minds. McNamara JA Jr (ed.). Monograph 41, Craniofacial Growth Series, Ann Arbor, USA, 2004.

Singh GD. Epigenetic orthodontics: Developmental Mechanisms of Functional (Formational) Orthodontic Appliances. J Am Orthod Soc. 2010; 10(6): 16-26.

Singh GD, Heit T, Preble D. Changes in 3D midfacial parameters after biomimetic oral appliance therapy in adults J Ind Orthod Soc. 2014 (in press).

I believe age is not really a limiting factor if cooperation is good, too. There are some studies (Pancherz, Ruf) that shows good results in Class II treatment using rigid fixed functional appliances even after 18 years of age. I have experience of treatment patients 21 - 25 years old with over 60% of the success. Older patients: most dental, less skeletal effects.

If your objective is the correction of a Class II with say, a Frankel or Bionator, then stick with the idea that it should be done during growth. If there is no growth, then your objective is a mandibular repositioning. This is where a neuromuscular diagnosis (Jankelson) is a must: you cannot reposition the mandible at your choice, only the muscles decide if it's ok. Extrusion of the posterior is more difficult in the adult.

Dr Fabio: It is now known that mandibular repositioning appliances can, in some cases inadvertently, induce mandibular growth in adults. The muscles are not IMHO the final arbitrator - it's the upper airway. The "neuromuscular response" in this example are the respiratory centers detecting oxygen desaturation (or hypercapnia). The muscles respond by changing posture in an attempt to open the airway; bone remodeling ensues, which can involve bone growth in adults, depending on genetic potential. I cover these topics extensively in my seminars on Pneumopedics(R), which is defined as non-surgical upper airway remodeling, as well as in my book "Epigenetic orthodontics". Best wishes -

Dear colleagues.Thank you all for your scientific comments. Based on my clinical experience in treating many cl ll adults for almost 10 years and following them for possible relaps of treatment it seems to me that age is not a limmiting factor if cooperation is OK and mandibular growth may take place and if good occlusin is attained at the end of treatment it is defenitely stable. The changes in my cases are both dental and skeletal.

Dear Dave Singh,

1) There is NO growth in adults but remodelling. The remodelling occurs when the use of the appliance stretches muscles on bone. 2) The upper airway is not an active element but a space. It is the result of many factors (epigenetic, genetic, etc.). It is true that the postural changes are adaptations for better airway freedom, but are more likely involved for the determination of mandibular posture, that is, modulation of the masticatory system. This is what we are talking about.

I understand you are promoting your book and seminars, as well as your publications, but it is the number of citations that makes the difference. I also understand that the idea of putting something new in our field is very tempting, although it must be said that there is very little to add to Solow, Bjork, and McNamara and so on. Best wishes.

Dr Fabio: We were awarded a prize at the International Association for Orthodontics (March 2013) for showing bone growth in adults. We measured bone volume prior to and after epigenetic treatment. The full paper is currently being published in an Orthodontic journal (JIOS). I'd be happy to send you a reprint once it has been published. In addition, we were also awarded a prize at the International Association for Orthodontics this year (March 2014) for showing increased airway volume in adults. We measured nasal cavity volume prior to and after epigenetic treatment. That paper has been accepted as a presentation at this year's medical Sleep (AASM) meeting, and is currently under peer review. I'd be happy to send you a reprint of that paper once it's been thru the peer-review process also. Best wishes -

Thank you Singh! I'd be happy to receive the papers from you. I do agree in increase in nasal cavity volume. What was the epigenetic treatment you did?

FS

Fabio: I will send the papers to you as soon as they're in print. The epigenetic treatment we did is called the "DNA appliance(R) system". Thanks and best wishes -

Dear Dr. Fabio Savastano, my objective is the correction of a Class II malocclusion. Mandibular repositioning is one of the main goals in Class II treatment. You are right! How we can make mandibular repositioning in the practice: stimulate the growth, eliminate functional factors or make surgical treatment. In Class II non growing patients (even after 21 years old, as I previously said) is possible to achieve forward mandibular advancement using rigid fixed functional appliances (e.g. Herbst appliance). TMJ remodeling is achieved during the treatment (Ruf, Pancherz…). The muscles are some of the main factors of relapse. That is why the recommendations of lifetime retention in some cases.

I think with current research, it is known that a change in the position of the mandible is associated with a change in the pattern of gene expression. We are talking about growth and development, which is followed downstream by remodeling, according to temporo-spatial patterning. As long as a population of stem cells exists, new tissues can be regenerated. This is true for the mandible, as well as any other bone in the body. We have been able to "re-grow condyles" in patients with hemifacial microsomia, which suggests that a population stem cells likely exists in the intermediate cell layer in the condylar neck. Our experience also appears to show that continued mandibular growth in some adult patients following treatment with mandibular advancement devices for the treatment of OSA.

Dear Prof Singh, Would you please send me a copy of your papers too. I need to refer to them for presenting my treated cl II adult cases.

Davood: Most of my papers are either uploaded on this RG website (or on my website dnaappliance.com under "Publications"). Thank you -

Sir

Although we have been taught that functional appliances work best in growing age, at peak pubertal spurt but personally, we at our university are treating lot of adult patients showing positive VTO with twin block appliance. They show good co-operation and yield good results (both skeletal and dental). Once occlusion gets established in fixed orthodontic appliances, their relapse is also minimal. We plan to publish this data soon. I strongly believe that functional appliances can work well in adult age group also keeping in mind their indications.

I agree that earlier the better...but I would recommend that you try not only fixed functional but removable functional appliances (twin block) in adult patients with positive VTO followed by fixed orthodontic treatment...they yield promising results...

Also ours is a developing country ... and sometimes patients are unable to bear additional cost of fixed functional appliance ...removable functional appliances are more cost effective and can be a good option.

Dear Davood Rowshan,

we are also treating cases with removable appliances and results are good. especially  those who are not able to afford for fixed functional appliances.

one more important point is that cooperation of the patient is very important for removable appliances.

Dear Dr Nirmala

How is your experience treating adult patients with removable functional appliances

Dear Group, I very much enjoyed this discussion and your input based on your personal outcomes with patients. Might any of you be interested in contributing to a journalistic article and documentary I will be making on the consequences of premolar extractions, and possible treatment plans to reverse the resultant narrow palate? If so, please write me at [email protected]. I am a professor and journalist, and wish to make the problem of extractions--and the viability of alternatives to surgery--known to a general public.

Skeletal age is more appropriate to formulate the treatment plan for growth modification rather than basing the treatment plan on chronological age. The peak growth occurs around stage CVS 3 which is when the functional appliances would be useful. Functional appliances used at a later age lead to mostly dentoalveolar effects, so should be used only when indicated