Distraction osteogenesis RED (Rigid External Distraction) of Mid-Facial Deficiency Dr. Aghyad al Mobayed Consultant Oral& Maxillofacial surgeon Al Shifa Hospital - Gaza ,Palestine

Distraction osteogenesis It is a biological process of new bone formation between the surface of osteomized bone segments that are separated gradually by incremental traction.

Distraction osteogenesis According to Arauson D.O is mechanically induced, intra- membranous ossification between two living bone surface acutely separated by low energy techniques undergoing gradual separation.

Distraction Osteogenesis Tension within the callus stimulates new bon formation parallel to the vector of distraction. Tension is created in the surrounding soft tissue leading to distraction histogenesis ( active histogenesis in skin ,fascia, blood vessels ,nerves ,ligament ,cartilage & periosteum ).

Illizarov 1951 Gavriil Abramovich Ilizarov Tissue engineering slow gradual distraction of osteomized bone fragment.

The clinician is able to guide the formation of New Bone without growth factor or other controlling agents.

Dentofacial Traction Fauchard 1728 : expansion arrches Wescott 1859 : correct cross-bite Angel 1859 :rapid palatal expansion Goddard 1893 : standarized the palatal expansion

Distraction Codvilla 1905 : first bone distraction femur Abbot 1927 : tibia Wassmund Rosenthal 1927 :first osteodistraction

Kazanjian 1937

Maxillofacial Region The cranio facial skeleton are much more suited for distraction: 1-Membranous in embryological origin. 2-Smaller dimension. 3-Richer blood supply.

Distraction can be done for various Cranio-Facial Structure like : 1- Mandible. 2- Maxilla. 3- Zygoma. 4- Cranium. 5- Alveolar Bone.

Biomechanics of Distraction Critical factors of the process: 1- Stability of fixation. 2- Rate of daily distraction. 3- Preservation of local soft tissue. 4- Vascular supply.

Classification of Distraction Pure lengthening procedure Corrective distraction osteo- tomies Transportation distraction Stimulation of growth

Target of Distraction Endochondral ossification Intermittent compressive Tensile stress Intramembranous new bone formation Constant compressive stresses Chondrgenesis Fibrous tissue formation High shear stresses

Stages of D.O Clinically , D.O consists of five sequential stages: 1- Osteotomy. 2- Latency. 3- Distraction. 4- Consolidation. 5- Remodeling.

Fracture Healing Fracture healing Impact Induction Inflammation Soft callus Gradual traction Hard callus Remodeling

Before After

Before After