Lengthening limb bones

Distraction osteogenesis
The periosteum appears just below the skin.
bone marrow
Anatomical terminology []

Distraction osteogenesis (DO), also called callus distraction, callotasis, and osteodistraction, is a process used in orthopedic surgery and oral and maxillofacial surgery to repair skeletal deformities and in reconstructive surgery. The procedure involves cutting and slowly separating bone, allowing the bone healing process to fill in the gap.

Distraction osteogenesis (DO) is used in orthopedic surgery and oral and maxillofacial surgery to repair skeletal deformities and in reconstructive surgery. It was originally used to treat problems like unequal leg length but since the 1980s is most commonly used to treat issues like hemifacial microsomia, micrognathism (chin so small it causes health problems), craniofrontonasal dysplasias, craniosynostosis, as well as airway obstruction in babies caused by glossoptosis (tongue recessed too far back in the mouth) or micrognathism.

In 2016 a systematic review of papers describing bone and soft tissue outcomes of DO procedures on the lower jawbone was published; the authors had planned to do a meta-analysis but found the studies were too poor in quality and too heterogeneous to pool. 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). For soft tissue, little evidence was available regarding the vertical dimension, while a 90% correspondence between skeletal and soft tissue was found for sagittal positioning; the dental-to-soft tissue agreement was around 20%.