Long-term Evaluation of Treated Class II Division 1 Malocclusions Utilizing the PAR Index

The PAR Index was used to evaluate treatment and long-term post-retention results obtained from 50 Class II division 1 malocclusions. Dental casts were used to record the occlusions pre- and post-treatment as well as 1 and 10 years post-retention. The results suggested a high treatment standard, as indicated by mean percentage PAR score reduction.

However, maintenance of post-treatment results 1 and 10 years post-retention was only achieved in 60 and 38 per cent of cases, respectively. The major factor involved in this deterioration appeared to be late lower anterior crowding.