The Oberg, Manske, Tonkin Classification of congenital anomalies of the hand and upper limb utilizes dysmorphological concepts to distinguish Malformations from Deformations and Dysplasias. Malformations are abnormalities of Formation and/or Differentiation of tissues. Deformations are abnormalities which occur after tissue is formed. Dysplasias are abnormalities which result from a lack of normal organization of cells into tissue. Malformations are sub-grouped according to whether the abnormality affects the hand alone or the whole of the upper limb; and according to which, if any, of the three main axes of development are primarily involved. It is not possible to satisfy all criteria which would define an ideal classification. However, this system is practical in that it retains the surgical diagnoses and sub-classifications familiar to surgeons and is easily utilized; it is expandable and may be modified without destroying its structure; it may be used to accumulate prevalence data; and, in the future, gene and chromosomal defects which are identified for specific diagnoses may be incorporated into the system.
Keywords: Classification; OMT Classification; congenital anomalies; hand; upper limb.