It is important that resources for orthodontic treatment within the Health Service Executive (HSE) are directed towards those children most in need of treatment. At present, children are referred using existing HSE guidelines.To assess the level of treatment need in a sample of patients on the orthodontic waiting list in the North Eastern division of the HSE using the Index of Orthodontic Treatment Need (IOTN) as an objective comparison. Also, to compare these results with the findings of a similar audit in 2003 and to assess the effectiveness of recommendations from the 2003 audit.Fifty models from each of two orthodontic units were selected. These were scored for the dental health component (DHC) and aesthetic component (AC) of IOTN by a calibrated examiner.In the 2005 audit, 100% of patients fell into DHC grades 4 or 5. These grades constitute a great need for treatment on dental health grounds. In the 2003 audit, 97% of patients fell into these two grades. The remaining 3% of children in 2003 were fostered and therefore entitled to orthodontic treatment under HSE guidelines. An average of 63.5% of patients fell into AC grades 8-10, i.e., deemed to be in great need of treatment on aesthetic grounds.The HSE screening guidelines identify patients in great need of orthodontic treatment using IOTN as an objective assessment of this need. The sensitivity of these guidelines requires assessment by measuring the level of unmet treatment need in 15-year-olds in the region. Recommendations arising from the 2003 audit relating to the filling of referral forms and the improvement of study model quality were found to have been effective.