The most commonly cited definitions relevant to the field of special care in dentistry are those of the World Health Organization in 1976 and 1980, which drew a distinction between impairment, disability and handicap. These were defined in 1976:
A handicap is a disadvantage for a given individual, resulting from an impairment or a disability, that prevents the fulfilment of a role that is considered normal (depending on age, sex and social and cultural factors) for that individual.
According to activists in the disability movement, the WHO definitions did not distinguish between the physical and social implications of the terms ‘disability’ and ‘impairment’. They maintained that impairment refers to physical or cognitive limitations that an individual may have, such as the inability to walk or speak. In contrast, disability refers to socially imposed restrictions, that is, the system of social constraints that are imposed on those with impairments by the discriminatory practices of society.
A disability is the disadvantage or restriction of activity caused by contemporary organisation, which takes no or little account of people who have physical impairments and thus excludes them from the mainstream of social activities.
Furthermore, according to the United Nations Standard Rules on the equalisation of opportunities for persons with disabilities, the term ‘disability’ summarises a great number of different functional limitations occurring in any population, in any country, of the world. People may be disabled by physical, intellectual or sensory impairment, medical conditions or mental illness. Such impairments, conditions or illnesses may be permanent or transitory in nature. The term ‘handicap’ means the loss or limitation of opportunities to take part in the life of the community on an equal level with others. It describes the encounter between the person with a disability and the environment. The purpose of this term is to emphasise the focus on the shortcomings in the environment and in many organised activities in society – for example, information, communication and education – which prevent persons with disabilities from participating on equal terms.
In view of the above, in 1980, the WHO adopted an International Classification of Impairments, Disabilities, and Handicaps, which provided a more precise and at the same time relativistic approach. WHO (1980) definitions then are:
An impairment is a loss or abnormality of structure or function including psychological functioning. Examples are • reduced visual acuity • diminished hearing capacity • lack of muscular control • decreased learning ability • an inability to concentrate.
A disability is a restriction or lack of ability to perform an activity within the range considered normal for a human being. Some prefer the term difficulty, as in ‘learning difficulty’. A person is considered to have a disability if there is a physical or mental impairment which ‘substantially’ limits one or more major life activities which include, but are not limited to: • breathing • caring for oneself • concentrating • hearing • interacting with other people • learning • lifting • performing manual tasks • reaching • reading • seeing • speaking • standing • thinking • walking • working.
This terminology recognises the necessity of addressing both the individual needs (such as rehabilitation and technical aids) and the shortcomings of the society (various obstacles for participation). In other words, an impairment is a loss or abnormality; a disability is a functional limitation of ability; a handicap is something which is imp/>