Objectives: This study aimed to examine the relationship between socio-economic status and both normatively assessed and self perceived need for orthodontic treatment.
Methods: More than six thousand 14-year-old children were assessed for orthodontic treatment by trained and calibrated examiners. The Index of Orthodontic Treatment Need was the measuring instrument along with a questionnaire which asked: "Do you think your teeth need straightening?"
Results: Normative need for orthodontic treatment (IOTN >3) was more common amongst deprived children than among their affluent counterparts. The same was found for perceived need. However, the children who wanted treatment were not necessarily those who needed it and vice versa.
Conclusions: Socio-economic status affects normatively measured orthodontic treatment need through, as yet, undefined mechanisms. It also affects a person's perception of need for orthodontic treatment, but these two associations are separate. The mismatch of need and desire for treatment is a problem for orthodontists.