Over the past 18 years of oral maxillofacial surgery practice, Dr. Ramsey M. Fanous has developed a special interest in osseous (bone tissue) reconstruction. This article, written by Dr. Fanous, will focus on a simple and relatively atraumatic approach for lateral alveolar ridge augmentation, necessary to restore the lost bone dimension when the jaw ridge gets too thin to place conventional implants. Having sound osseous and soft tissue architecture for implant placement results in consistently aesthetic, predictable and long-lasting implants.
By Ramsey M. Fanous, DDS
Although guided bone regeneration (GBR) and block grafting have been in use for well over two decades, clinical studies have shown that these procedures do have their deficiencies. Many alveolar ridges augmented with block grafts have shown significant resorption 10 years later in spite of implant placement in the site. GBR is excellent for small lateral defects, but does not provide predictable results in large defects especially with vertical gain.
A simple technique that can be applied frequently is the alveolar split graft known as the book flap described by Ole Jensen, DDS*. We utilize this procedure for most lateral augmentations for maxillary and mandibular alveolar ridges with deficiencies. This technique differs from a traditional ridge splitting technique in that the mucoperiosteum (soft tissue attachment) is not dissected free from the facial/buccal alveolar plate to widen the ridge. Once the soft tissue is dissected free from the facial aspect of the alveolus and the ridge split occurs, the osseous site then essentially becomes a non-vitalized graft physiologically similar to a block graft. The book flap is used to increase alveolar width 2-5 mm and up to 6 mm in certain cases. This procedure can be used with immediate implant placement (2 mm of facial alveolar plate is required) or delayed implant placement. The relatively soft bone in the maxilla is amenable to this technique especially in the aesthetic zone. In the mandible, this procedure is more difficult due to the thickness of the cortical bone. From experience, a two-stage procedure is preferable in the mandible.
In experienced surgical hands, the procedure is relatively simple. A crestal incision is created in the desired edentulous space. This incision is palatal to the crestal midline with minimal soft tissue reflection to visualize the alveolar crest. A sharp osteotome or a piezo electrical saw is used to create a crestal osteotomy extending to a depth of approximately 10 mm. This osteotomy must be 2 mm away from the adjacent periodontal ligament spaces of the adjacent teeth. Next, the vertical component of the osteotomy is completed within the alveolus and extended through the facial plate. The facial segment is then spread to the desired width. Allograft with or without the BMP (bone morphogenetic protein) can then be packed in the osteotomy site. A collagen membrane is then placed over the site with resorbable sutures. Physiologically, this will heal very similar to an extraction site with allograft placement. In a staged procedure, the implant placement can follow this initial procedure three to four months postoperatively. In the mandible, and inferior horizontal osteotomy is always necessary in order to be able to spread the bone to the desired thickness. This is due to the thickness of the cortical bone. From Dr. Fanous’ experience at Texas Oral Surgery Group, he believes the two-stage procedure is preferable. Stage one surgery requires a soft tissue dissection followed by the vertical and inferior horizontal osteotomies. Dr. Fanous makes the crestal osteotomy to the desired depth. There is no mobilization of the osseous segment at this stage. The tissue is then primarily closed. Stage two surgery occurs at a minimum of 28 days following the initial procedure. This allows for revascularization of the surgical site. A minimally invasive second procedure is completed as described above in the maxilla. The bone segment with attached tissue and blood supply is easily spread to the desired width.
The book bone flap is simple and the complications are minimal. Potential complications can include infection or potential sequestration, however, these are rare. This procedure has great utility and versatility and can be used in all locations in the oral cavity. The advantage of this procedure is the ability to displace a solid plate of vital bone to restore a resorbed facial plate. This is a very important advantage when considering placement of implants in the aesthetic zone.
* Jensen OT, Ellis E. The Book Flap; a technical note. j Oral Maxillofacial Surgery 2008;66(supple):43-61.
If you would like to know more about ridge augmentation, possible complications or how to recover after surgery, call Texas Oral Surgery Group at 972-471-9596 to arrange an appointment or visit the website at www.texasoralsurgerygroup.com.
Texas Oral Surgery Group
Plano, Allen, Denton, Decatur, Gainesville, Texas