Scoliosis prognosis of scoliosis depends on the likelihood of progression. The general rules of progression are larger curves carry a higher risk of progression than smaller curves, and thoracic and double primary curves carry a higher risk of progression than single lumbar or thoracolumbar curves. In addition, patients not having yet reached skeletal maturity have a higher likelihood of progression (i.e., if the patient has not yet completed the adolescent growth spurt). Scoliosis affects 2–3% of the United States population, which is equivalent to about 5 to 9 million cases. A scoliosis spinal column's curve of 10° or less affects 1.5%
Supernumerary body part Supernumerary body part Supernumerary body parts are most commonly a congenital disorder involving the growth of an additional part of the body and a deviation from the body plan. Body parts may be easily visible or hidden away, such as internal organs. Many additional body parts form by the same process as conjoined twins: the zygote begins to split but fails to completely separate. This condition may also be a symptom of repeated occurrences of continuous inbreeding in a genetic line. Specific types of additional body parts include: Vestigial structures are anatomical structures of organisms in a species which are