Agreement and association between normative and subjective orthodontic treatment need using the Index of Orthodontic Treatment Need.

Aims: To determine the association and level of agreement between young adults' perception of orthodontic treatment need (subjective need) and the orthodontists' assessment of treatment need (normative objective need).

Methodology: For this study, 670 students [280 males and 390 females; mean age (standard deviation) of 15.32 (1.81) years] were selected from public and private schools from different demographic areas of Jeddah city, Saudi Arabia, and divided into two age groups (12-15 years) and (16-19 years). All the participants were examined, and the Index of Orthodontic Treatment Need (IOTN) components [dental health component (DHC) and aesthetic component (AC)] were recorded.

Results: Kappa statistics showed a statistically significant but fair agreement between clinician AC (CAC) and student AC (SAC) assessments in both age groups ( = 0.343 and 0.334, respectively; < 0.001), whereas Spearman's correlation coefficient showed a statistically significant but moderate association ( = 0.487 and 0.517, respectively; < 0.001). The degrees of agreement were 76.4% and 76.7% at the no-need and mild-need levels of treatment, respectively. There was a statistically significant but weak association between the subjective and normative needs (SAC and IOTN-DHC) in both age groups ( = 0.336 and 0.360, respectively; < 0.001). However, the degrees of agreement were 58.9% and 61.5% at the no-need and mild-need levels of treatment, respectively.

Conclusion: Significant but weak positive association was found between the normative and subjective orthodontic treatment needs, indicating a lack of understanding of the nature of malocclusion and its consequences. Thus, promoting further knowledge and awareness of malocclusion are indicated.