Distraction osteogenesis

Distraction osteogenesis (DO) is used in orthopedic surgery, and oral and maxillofacial surgery to repair skeletal deformities and in reconstructive surgery. From what they were able to generalize, the authors found there was significant relapse in the vertical plane for bone, and a higher risk of relapse when there was an initial high gonial angle or Jarabak ratio (sella–gonion/nasion–menton). This was not sufficient evidence from which to generalize, but the authors noted that while both procedures produced notable hard and soft tissue improvements, the DO group had greater advancement of the maxillary and less horizontal relapse five years after surgery. There was no difference in speech or nasal emissions outcomes nor in adverse effects; the DO group had lower satisfaction at three months after surgery but higher at two years. ==Procedure==

In the first phase, called the "osteotomy/surgical phase", the bone is cut, either partially, only through the hard exterior, or completely, and a device is fitted which will be used in the next phases. In the second phase, the latency period, which lasts generally seven days, the appliance is not activated and early stages of bone healing are allowed. In the third phase, the "distraction phase", the device, which is mounted to the bone on each side of the cut, is used to gradually separate the two pieces, allowing new bone to form in the gap. When the desired or possible length is reached, which usually takes three to seven days, a consolidation phase follows in which the device keeps the bone stable to allow the bone to fully heal. After the consolidation phase, the device is removed in a second surgical procedure. Advantages of this device are accurate deformity correction, low scar tissue formation, and reduced risk of infection. Furthermore, the patients describe the procedure as more comfortable than limb lengthening with mechanical systems. ==Risks==

Risks include infection (5% overall, with 1% of those requiring pin removal and the bone becoming infected in 0.5%), failure of bone to grow in the desired direction (between 7 and 9%), hardware failure (between 3 and 4.5%), failure to follow the distraction protocol (4.5% overall; too slow 2% and too fast 0.5%), 1% pain due to distraction ending the procedure; damage to the inferior alveolar nerve occurs in 3.5% of mandibular distraction, tooth bud injury in 2%, and facial nerve injury in 0.5% of cases. ==History==

The procedure was first proposed by Bernhard von Langenbeck in 1869, but the first publication of efforts to implement it clinically was by Alessandro Codivilla in 1905. His paper showed high levels of complications, including infection, tissue death, and bones that failed to join, and his methods were not adopted. ==Society and culture==

In India, cosmetic limb-lengthening surgery is of high demand but is also a unregulated industry. Height is considered highly attractive in India and cosmetic limb-lengthening has been used by young Indians to improve marriage and career prospects. Others have used it in preparation for a new job in foreign countries such as the United States. In 2006, limb lengthening was banned by China's Ministry of Health after a series of operations resulting in serious side-effects. The plot of the 1997 American dystopian science fiction film Gattaca involves one character assuming the identity of another and leg lengthening is depicted as part of the elaborate ploy to achieve this subterfuge, along with the use of various bodily fluids to avoid detection by DNA sequencing. ==Research directions==

As of 2013, work was underway on distraction devices using Shape-memory alloy that could precisely separate bone without the need for intervention, as well as springs and motors; the use of biopharmaceuticals like BMP in combination with devices was also being explored. As of 2016, work was underway developing devices and techniques that would allow DO in more directions simultaneously. == See also ==