Assessment of orthodontic treatment need: a comparison of study models and facial photographs.

OBJECTIVES: The current study aims to examine how orthodontic treatment need is prioritized depending upon whether dental study models or facial photographs are used as the means of assessment.

METHODS: A group of three orthodontists and three postgraduate orthodontic students assessed: (i) dental attractiveness; and (ii) need for orthodontic treatment in 40 subjects (19 males, 21 females). The 40 subjects displayed a range of malocclusions. Separate assessments were made from study models and facial photographs.

RESULTS: There was a bias towards higher scores for dental attractiveness from facial photographs compared with assessment of study casts, for all examiners. This was statistically significant for five of the six examiners (P = 0.001-0.101). The need for orthodontic treatment was rated as 20% higher from study models compared with facial photographs (P < 0.001); overall the level of need for orthodontic treatment was rated as 18.9% higher from study models compared with facial photographs (P < 0.001). Reproducibility analyses showed that there was a considerable variation in the intra- and inter-examiner agreement.

CONCLUSIONS: This study shows that a group of three orthodontists and three postgraduate students in orthodontics: (i) rated orthodontic treatment need higher from study models compared with facial photographs and; (ii) rated dental attractiveness higher from facial photographs compared with study models. It is suggested that the variable intra-examiner agreement may result from the assessment of orthodontic treatment need and dental attractiveness in the absence of any specific assessment criteria. The poor reproducibility of assessment of orthodontic treatment need and dental attractiveness in the absence of strict criteria may suggest the need to use an appropriate index.