Healing Severe Facial Clefts with Bone-Growing Technology
How a groundbreaking surgical technique is using the body's own regenerative power to rebuild faces from within.
Imagine the intricate architecture of the human face—the subtle curves of the cheekbones, the strong bridge of the nose, the framework that allows us to smile, speak, and connect. For children born with severe facial clefts, this architecture is fundamentally disrupted.
A #7 facial cleft, also known as a Tessier #7 cleft, is a rare and complex condition where a split extends from the corner of the mouth towards the ear, affecting not just soft tissue but the critical underlying jawbone (mandible). Traditional surgeries often rely on borrowing bone from other parts of the body, like the hip or rib—a painful process with limited supply and significant recovery.
But what if surgeons could instead coax the body into growing new bone right where it's needed? A revolutionary technique is doing exactly that. It's called Distraction-Assisted In Situ Osteogenesis (DISO), and it's supercharged with a powerful biological signal: recombinant human Bone Morphogenetic Protein-2 (rhBMP-2). This isn't just repair; it's regeneration.
A #7 cleft is more than a gap in the skin. It represents a missing section of the mandible, the bone that forms the lower jaw. This absence can cause:
The gold standard treatment has been bone grafting. Surgeons harvest bone from the patient's hip (iliac crest graft), sculpt it to fit the defect, and fix it in place. While often successful, this approach has downsides:
The DISO procedure elegantly addresses these limitations by combining two advanced concepts:
This is the "scaffolding" phase. Surgeons carefully cut the existing, underdeveloped bone on either side of the cleft and attach a device called a distractor. Over several weeks, this device is slowly turned (like a tiny crank), millimeter by millimeter, gently pulling the two bone segments apart. This controlled tension triggers the body's natural healing response, stimulating new bone formation in the gap between the segments.
This is the "filling" phase. While DO creates bone in a narrow gap, the wider defect of the cleft itself remains hollow. This is where ISO comes in. Instead of taking bone from elsewhere, surgeons implant a special collagen sponge soaked with rhBMP-2 directly into the defect.
Bone Morphogenetic Protein-2 is a naturally occurring protein in our bodies that acts as a master switch for bone formation. It signals stem cells to become bone-forming cells (osteoblasts). Recombinant human BMP-2 is a lab-produced, pure version of this protein.
In the DISO technique, the rhBMP-2 is delivered using a Helistat-activated collagen implant. Think of this as a biodegradable "sponge" that serves two crucial functions:
The combination of the mechanical stimulus from the distractor and the powerful biological signal from the rhBMP-2 creates a super-charged environment for robust, high-quality bone growth exactly where nature intended it to be.
Recombinant Human Bone Morphogenetic Protein-2
Let's examine how this innovative technique was applied in a real-world scenario, as detailed in surgical literature.
To reconstruct a large mandibular defect in a young patient with a #7 facial cleft using the DISO technique with rhBMP-2/Helistat, avoiding a traditional bone graft.
The procedure was meticulously planned and executed in distinct stages:
Advanced 3D CT scans were used to create a precise model of the patient's skull, allowing surgeons to plan the bone cuts and the placement of the distraction device.
Under general anesthesia, a custom-designed distractor was fixed to the healthy sections of the mandible on either side of the cleft. A precise cut (osteotomy) was made in the bone to create a segment that could be moved.
The surgical site was allowed to rest and begin healing for 5 days.
The distractor was activated, moving the bone segments apart at a rate of 1 mm per day. This continued for 20 days, creating a 20 mm gap of new bone formation.
Once distraction was complete, the original cleft defect (now adjacent to the newly formed bone) was filled with the rhBMP-2-soaked Helistat collagen sponge.
The distractor was left in place, acting as a rigid stabilizer for 3 months as the new bone from both the distraction and the rhBMP-2 implant matured and solidified.
After consolidation, the distractor was surgically removed.
The results were striking and demonstrated the procedure's success both visually and functionally.
This case proved that DISO with rhBMP-2 is a viable and powerful alternative to traditional methods. It showed that the body can be guided to regenerate large volumes of functional bone without the need for harvesting from another site.
This breakthrough wasn't possible without a suite of specialized tools and biological agents.
| Research Reagent / Material | Function in the DISO Procedure |
|---|---|
| Recombinant Human BMP-2 (rhBMP-2) | The biological "instruction signal." It binds to cell receptors and directs stem cells to differentiate into bone-forming osteoblasts. |
| Helistat® Absorbable Collagen Hemostat | A biocompatible, sponge-like scaffold. It acts as a delivery vehicle for rhBMP-2, holding it in place and providing a matrix for cells to migrate into and form new bone. |
| Custom Mandibular Distractor | A mechanical device fixed to the bone with screws. Its slow, controlled expansion creates mechanical tension that stimulates the body's innate bone-growing capabilities. |
| 3D-CT Imaging & Surgical Modeling | Allows for precise preoperative planning. Surgeons can create 3D-printed models of the patient's anatomy to pre-bend distractors and plan osteotomies for perfect fit. |
The DISO technique, augmented with rhBMP-2, represents a paradigm shift in reconstructive surgery. It moves beyond the paradigm of "borrowing and patching" and into the future of guided regeneration. By harnessing and amplifying the body's own healing mechanisms—using mechanical distraction and powerful morphogenetic proteins—surgeons can now rebuild complex craniofacial structures with remarkable precision and minimal cost to the patient.
While further research and long-term studies are always valuable, this approach offers immense hope. It's not just about closing a gap; it's about building a foundation for a better life, one millimeter of new bone at a time.