The question of bone versus soft tissue only

1) I know we have come a long way in bone regeneration but I was always taught that regenerating bone outside of the alveolar housing is very difficult and challenging. Over the last 20+ years I have experienced these challenges myself in my clinical practice. Why is it then that now with the POPA procedures we can add non-autogenous bone graft material (oftentimes without the addition of any biologics or membranes as in the original Wilckodontics technique) and have this  bone graft material turn into vital bone that can support moving teeth significantly outside of the alveolar housing? Do we actually have any evidence besides post-op CT scans (which may only be showing the non-resorbed bone graft material) that these facially and lingually applied bone grafts are turning into actual vital bone, i.e. that we are truly regenerating bone…..Or are they just turning into a thick encapsulated collagen matrix, a “glorified thick soft tissue”?

Firstly, I would highly recommend Brugnani's text for an excellent overview on this emerging and wonderful technology.  Quite frankly, I think that orthodontists not incorporating POPA into their daily schedule are not practicing at the level of care required today.  See Fig. 1 below.

Tom Wilcko elegantly demonstrates, histologically new bone, similar to GBR type bone at sites where bone was not previously present.   My experience is that we can adequately grow GBR type bone where root surface exposure has not occurred.  I have not been successful in demonstrating on follow up CBCT definitive bone on previously exposed root surfaces.  Therefore, the presence of an intact periodontium, albeit without alveolar bone,  for example a fenestration or dehiscence with intact untouched connective tissue attachment lends itself to this situation.

I have at least six re-entry cases demonstrating this phenomenon histologically. See one of my re-entry histological cases, Fig. 2, below.

2) For 3-4 decades clinicians have routinely done pre-orthodontic gingival augmentation AND root coverage procedures in Ortho and non-Ortho cases without adding any bone. But we have not experienced any significant recurrence of recession post gingival grafting (by whichever means). Clinicians have presented their long-term 20+ year results of stable soft tissue grafting results. Are they cherry picking and choosing what they show? Is post-operative recession indeed being experienced by all these patients and are we just sweeping these failures under the rug or are we not following these patients long enough to see these recurrences?

Difficult answer.  Some of our worst recession cases are post orthodontic.  Renkema, in a terrific Meta Analysis, demonstrates the risk of post orthodontic crowding 4x-8x greater in the treated crowded dentition than in the not treated dentition.  And of course, that makes sense that most orthodontic treatment for crowding is arch expansion, especially in the mandibular arch where we cannot gain space, as we do in the maxillary arch through SARPE's or other procedures.

However the cases that  these clinicians show are post recession.  The recession and particularly the relapse (up to 75% between 10-20 years is avoidable if hard and soft tissue grafting is completed before initiating orthodontic de-crowding treatment.

3.) Danny Buser very honestly points out that with his buccal bone grafting technique he is not expecting all his bone graft to turn into solid vital bone and that is the reason he calls it “Buccal Contour Augmentation” rather than “Buccal Bone Augmentation”. It is now apparently universally accepted that we need a 2mm thickness of bone circumferentially around an implant for a long-term stable result (BTW: Can someone please point me to the research where this 2mm number came from…I am sure it exists but I just don’t have it).

The bone grafting material that Buser uses for contour augmentation is the same as the material that many of us use currently for POPA, which includes a very slow resorbing Bio-oss.  So if you look at the GBT or contour augmentation histology in which Bio-oss is used by Buser, you will see remants of unresorbed Bio-oss granules.  The same appearance as the histology I have posted.

The essence of my questions was not really to question the benefits of the corticotomies but rather whether we need the bone augmentation or whether soft tissue augmentation alone is sufficient (or do we need both as you have advised)?

Bone grafting materials are Bio-Oss  + DFDBA 2:1. I typically use a thin Alloderm covering the graft, both as a barrier and also to  thicken soft tissue.  This is a hypothesis - no evidence to support the concept. I do not use biologics.

Again, the reason for bone is both for soft tissue support and to limit further recession, but also to enhance orthodontic stability in the long-term.  This has been well documented and demonstrated by Ferguson and Wilcko with up to 10 year follow up. See Fig 3 below.

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Fig.1

Fig. 2

Fig. 3

POPA and PRPA Overview

Substantial  evidence associating orthodontic crowding with the 'shrinking human jaws",  from the anthropological perspective,  is available.  The consequence of this malady is that gingival recession, orthodontic relapse, less favorable esthetic results,  and root resorption are common iatrogenic complications, frequently associated with orthodontically treated patients. These complicating factors may occur either in the short term or many  years following treatment.  Of course these problems are present in the non-orthodontic patients as well.

Today, procedures exist which predictably minimize these problems.  I have created the acronym (POPA), Pre Orthodontic Periodontal Augmentation, or (PRPA), Pre Restorative Periodontal Augmentation,  to  describe a modification of the original Periodontally Accelerated Osteogenic Orthodontic Procedure (PAOO).  The POPA procedure is less invasive and seems to offer the same advantages seen with the typical PAOO procedure.  We are also providing POPA  therapy to younger patients, almost prior to the initiation of orthodontic treatment, when it is determined that there is a risk for future gingival recession. These augmentation procedures are also being provided to non-orthodontic patients prior to the onset of substantial restorative endeavors.

Essentially, POPA is an augmentation procedure provided for teeth demonstrating periodontal  dehiscences, fenestrations and a thin phenotype.  A  secondary benefit of POPA, for the orthodontic patient, is that teeth move  quicker due to the RAP effect and tooth movement through thin cortical bony plates (e.g. B point, occurs more readily).

Case Study #5

16 year old pre orthodontic and pre orthognathic surgical treatment. Note severe in the crowding mandibular anterior segment and class 3 skeletal jaw relationship. 

 

 

Intra-operative view at time of localized POPA treatment for teeth numbers 21-28, facial surface only. Note ultrathin facial bone with early dehiscences and fenestrations.

 

Four months post treatment (and preceding orthognathic treatment). Note robust muco-gingival periodontal health.



Pre Orthodontic Periodontal Augmentation (POPA) vs. Periodontally Accelerated Osteogenic Orthodontics (PAOO™)

1. POPA (Pre Orthodontic Periodontal Augmentation) is a periodontal surgical procedure to augment facially deficient alveolar bone (dehiscences and fenestrations) prior to initiation of orthodontic treatment. (Ref. Richman, Compendium 2011).
2. This treatment modality has been shown to minimize the risk of post orthodontic gingival recession and post orthodontic tooth relapse. 
3. If the patient or orthodontist is seeking accelerated tooth movement as well, lingual treatment (corticotomies) is electively provided. This typifies PAOO. However, if augmentation is the primary objective, only the facial aspects are treated. Pre-treatment CBCT is essential to facilitate the diagnosis and treatment plan.
4. POPA precisely defines what we are trying to achieve -- pre orthodontic periodontal augmentation. It is less confusing terminology than PAOO, Wilckodontics, SFOT, Piezocision, etc.
5. In summary, POPA addresses only the biological need for alveolar bone augmentation. In contrast, PAOO is a more aggressive surgical intervention which addresses both the biological need for augmentation of deficient bone sites as well as the elective lifestyle desires for accelerated orthodontic therapy.

 

 

 

 

 

Case Study #4

This case illustrates the need for POPA or PAOO™. At the time of PAOO™ surgery, note the severely deficient facial bony plates associated with teeth numbers 22-26 inclusive. Also note the CBCT scan demonstrating missing facial bone (RSBI C, Richman 2011).



 

Case Study #3

This patient was referred for closure of #23 extraction space and 3mm of
mandibular incisor intrusion as well as Pre Orthodontic Periodontal Augmentation (POPA) for teeth 21-28 inclusive. We placed a KLS Martin bone anchor and completed POPA treatment including substantial grafting and began orthodontic treatment the same day as surgery. Tooth movement was completed in less than 3 months. The lower images depict the new bone growth around the anchor observed at the time of anchor removal.

Case Study #2

This patient underwent orthodontic treatment twice as a teenager. She presented requesting esthetic enhancement, an improved bite, and concern about multiple site of gingival recession.

The upper six images depict her pre-treatment status. Total treatment time was eight months following comprehensive PAOO™ treatment. The lower five images depict her post treatment status four years later. Note the robust muco-gingival complexes.

 

 

Of particular note:

• The extent of maxillary right arch expansion;
• Improved muco-gingival stability at all sites;
• Triangular spaces due to tooth shapes with coronal contact points;
• Residual minor resection 3 years post-treatment remains unchanged and is being monitored closely;
• Miller Class 3 recession lesions;
• Patient is extremely happy and faithful with maintenance care.