Objectives: 1) assess the relationship between a measure of condition-specific oral health-related quality of life (OHRQoL) and the related normative need for dental treatments, and 2) test the diagnostic validity of the condition-specific OHRQoL measure for specific dental conditions in a group of primary school children.
Methods: A cross-sectional study of all 11 to 12 year-olds carried out in a municipal area of Suphanburi province, Thailand. 1034 children (91.8%) were dentally examined to assess their normative needs for 6 types of treatment (dental caries, traumatic dental injuries, enamel defects, periodontal, orthodontic and prosthodontic treatment). OHRQoL was assessed using the Child-OIDP index and its Condition-Specific impacts measure for the 6 treatment types.
Results: The prevalence of specific types of normative needs ranged from 3.2% (prosthodontic) to 97.0% (periodontal) and for Condition-Specific oral impacts from 0.7% (prosthodontic) to 50.6% (dental caries). Despite their statistically significant relationship for every treatment type except for periodontal treatment when need was indicated by a CPI score of 1, there were large differences between measures of normative need and oral impacts. High proportions of children had normative need without impacts and vice versa. The biggest differences were for appearance-related conditions (e.g. enamel defects and orthodontic treatment). For every type of treatment, oral impacts poorly predicted the normative needs of individuals.
Conclusions: Although normative needs and OHRQoL are associated, when assessed appropriately, there was considerable discrepancy between them. OHRQoL measures cannot replace normative needs. Instead, both should be used in combination in order to cover different dimensions of oral health.