Evaluation of orthodontists' perception of treatment need and the peer assessment rating (PAR) index

This paper examines the relationship between orthodontists' subjective asse ssment of treatment need and objective measurements obtained during standar dized intra- and extraoral examinations. Logistic regression modeling was u sed to develop predictive models of treatment need. Data were obtained from 1155 eighth-grade students by four orthodontists who used standardized exa mination forms to assess demographics, trauma, skeletal relationships, morp hologic malocclusion traits, and mandibular function. At the conclusion of the examination, the orthodontist rated the subjective treatment need as no ne, elective, recommended, soon, or immediate. For some analyses, the categ ories were collapsed to represent no need and need. The peer assessment rat ing (PAR) index (American validated version) was computed from the clinical exam findings and scoring of dental models; PAR scores were used to docume nt malocclusions severity and treatment difficulty. Spearman rank correlati on coefficients quantified the relationship between PAR scores and need cat egories. Logistic regression analysis modeled treatment need using componen ts of the PAR index as well as other variables. The components of these mod els, as well as sensitivity and specificity were compared with malocclusion severity/treatment difficulty scores obtained from malocclusion assessment s using the PAR index. The five subjective treatment need categories and th e PAR index scores were significantly correlated (rho=0.62, p<0.001). Signi ficant difference were detected between the need and no need groups for all PAR components (p<0.001). PAR index scores and predicted probabilities fro m logistic regression models performed equally well for classification purp oses (no need, need). The data suggest that the PAR index is highly correla ted with orthodontists' subjective assessment of treatment need when that a ssessment is made in the absence of financial considerations and patient de sires.