The periosteum is a remarkable tissue — very thin, yet surprisingly strong in addition to being packed with regenerative cells. The periosteum is responsible for healing all bone fractures, yet periodontics makes no use of this extraordinary tissue for healing periodontal lesions. First, we will look at the structure and cellular makeup of the periosteum and then we will introduce a surgical methodology for using the periosteum during periodontal surgery, followed by a few cases.
The Periosteum for Regenerating Periodontal Lesions
Typical orientation of the periosteum to underlying bone.
The periosteum is a nearly universal bonding agent between bone and the connective tissue that covers the periosteum. Tendons penetrate the periosteum, but the periosteum still exists in the area where the tendons attach to bone. However, the periosteum does not exist under the attached gingiva. This is a major factor in using the periosteum as an effective barrier membrane.
Another primary attribute of the periosteum is the very high concentration of regenerative cells. This histology of the periosteum shows collagen fibers stained green and regenerative cells stained red. The regenerative cells of the periosteum show cellular anastomoses that provide effective communication.
Most all dentists only see the periosteum when it is at rest. However, a tremendous proliferation of regenerative cells occurs when the periosteum is activated in a bone fracture and this proliferation of regenerative cells also occurs when the periosteum is used for regenerating periodontal lesions.
Twenty years ago, SteinerBio developed the Inverted Periosteal Graft to regenerate periodontal lesions. The periosteum is the only membrane we have used during that time for regenerating periodontal lesions. Let’s review the significant features of the surgery.
In this photo, a vertical incision has been made and a full thickness flap has been raised. Tissue pickups are holding the gingiva and where the vertical incision was made, a spoon was used to dissect the periosteum from the mucosa. The next step is to cut the periosteum at the base of the flap.
After root planing and grafting is complete, the apical extent of the periosteum in inverted and sutured over the grafted lesions. This photo shows the periosteum being sutured around the teeth. The gingiva that will be sutured over the periosteum can be seen at the top of the photo (white arrow). The periosteum is used and billed at a resorbable membrane.
This photo shows the surgical site after two weeks. One ideal characteristic of the periosteum is it is an absolute biological barrier to the gingiva. The gingiva will not approach the periosteum. The gingiva will not attach to the periosteum and all posterior papilla will appear like this at two weeks. The periosteum is also a very aggressive tissue and rapidly grows to surround the dentition. At this time, the regenerative cells of the periosteum recognize their surroundings and migrate into the periodontal defect.
A critical factor in tissue regenerative is that the regenerative cells must know where they are and what they are supposed to do. By placing the periosteum around the dentition over a periodontal defect, the regenerative cells have the orientation and guidance to migrate onto the tooth and into the bone lesion.
This patient presented with severe periodontal lesions.
Direct view of the furcation lesions.
The teeth were root planed and conditioned with EDTA. The bony lesions were grafted with Immediate Graft and the periosteum was dissected and inverted over the buccal, lingual, and distal surfaces of the affected teeth and then sutured in place. In this photo the periosteum is sutured over the lesions. Next the gingiva will be sutured over the periosteum.
Two months after surgery, all probings are within normal limits except the distal surface of the second molar, where calculus and a 7 mm probing exists. The decision was made to reoperate the site to resolve the 7 mm probing.
At the reentry surgery, the furcations were probed showing bone fill.
At the final evaluation, all probings were within normal limits.
Another case with severe lesions to the apex of the involved teeth. The distal molar was depressable with Class III mobility.
The lesions were root planed, treated with EDTA, grafted with Immediate Graft, and the periosteum was inverted and sutured over the grafted sites.
On the mesial molar, all probings were within normal limits. However, the distal molar again presented with a 7 mm lesion. The decision was made to reoperate to complete the regeneration on the distal molar. The reentry occurred 6 months after the initial surgery. During the reentry surgery, bone was removed from the mesial of the mesial molar.
The periodontal attachment is on the left. Its makeup and structure cannot be understood from this histology. The cancellous bone is composed of properly aligned trabeculae organized to carry load. There is no inflammation and a significant vascular supply is obvious. A few retained graft particles in the lower right section of this photomicrograph confirm this bone was taken from the grafted site.
Severe lesions allow us to see the potential of using the periosteum, but it also makes routine lesions more predictable. The first molar here presents with a common mesial Class II furcation.
Post-operative evaluation shows radiographic bone fill and clinically, probings are within normal limits.
The following patient presented with generalized periodontitis, poor oral hygiene, and a Type 1 diabetic. She received full mouth surgery under general anesthesia. The surgical therapy was full mouth inverted periosteal graft. The bone graft material was Socket Graft mixed with OsseoConduct βTCP perio granules in a one-to-one ratio.
Pre-op photos and probing.
Pre-op radiographs.
Post-op photos and probing.
Post-op radiographs.
While it is recognized that severe diabetics are more susceptible to disease, our experience is that they are respond equally to regenerative therapy.
The Inverted Periosteal Graft is a complex surgical procedure and requires training to achieve predictable results. The periosteum is not just a physical barrier, but a biological barrier. The periosteum and attached gingiva will not exist together. This is evident by the mucogingival junction. The same genetic determinants that stop the periosteum at the edge of the attached gingiva prohibit the attached gingiva from growing on top of the periosteum, thereby making the periosteum an ideal biological barrier to epithelium.
The periosteum is also a rich source for regenerative cells. The periosteum is composed of a dense fibrous layer of collagen and an inner layer called the cambium, rich in regenerative cells. One unfounded criticism of the inverted periosteal graft is that the cambium is inverted and when sutured in place will not face the lesion but be located on the outer surface of the periosteum. The criticism is unwarranted because all regenerative cells are mobile. The periosteum is a fraction of a millimeter thick and regenerative cell migration will happen quickly when placed near a periodontal lesion.
A caveat of using the periosteum to regenerate periodontal lesions is that you must use science based bone graft material that do not produce a chronic inflammatory response. As we discussed previously (link to article), for regeneration to occur, the site must move from acute inflammation to regeneration with no chronic inflammation. If you use materials, such as cadaver bone grafts, chronic inflammation develops and regeneration is blocked.
Periodontal therapy has not improved in 30 years since the development of the barrier membrane. Periodontists believe that cadaver bone grafts stimulate normal bone growth and as a result of this misinformation they have spent 30 years using these materials trying to improve periodontal outcomes to no avail. A complete generation of intelligent periodontists have failed to improve periodontal outcomes because they are misinformed and do not understand that cadaver bone grafts are blocking the regenerative process. Scientists in medicine and dentistry have abandoned research in cadaver bone grafts and have moved on to science based graft materials. Periodontal clinicians in both academia and private practice still hold onto the outdated theories about cadaver bone grafts. As a result, periodontics will fail to move forward with improved care until some in the profession have the courage to challenge the current dogma.
Please do not attempt to use of inverted periosteal graft in combination with any animal or human material. If you would like assistance in understanding this surgery and are interested in introducing regenerative medicine into your clinic, contact us as we are always willing to help.
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