Cephalometric appraisal of post-treatment tooth eruption: a 20 year follow-up study.

Aim: To assess the amount of tooth eruption that occurs during 20 years after completion of orthodontic treatment and analyse possible correlations with age and mandibular growth pattern present.

Materials And Methods: A retrospective longitudinal cephalometric investigation of dento-alveolar changes was performed in 72 patients (50 women and 22 men). Two lateral cephalograms, taken at the end of orthodontic treatment and on average 20 years later, were available for each subject. The mean age at the beginning of the observation period was 21.5 years and the mean observation period was 19.7 years. Changes in the cephalometric measurements were evaluated statistically.

Results: For all parameters, there is evidence for an increase in tooth eruption parameters during the 20 year interval. Furthermore, a significant difference in change was found between different growth patterns for all parameters. For the majority of the parameters, the increase is higher for subjects being younger at the end of orthodontic treatment. There is no evidence for a difference in change between males and females.

Conclusion: Continued tooth eruption readily occurs after termination of orthodontic treatment in all patients. There is a correlation between the mandibular growth pattern present and the amount of tooth eruption in posterior and anterior regions in both the mandible and the maxilla after completion of the orthodontic treatment. These changes are more pronounced in patients treated orthodontically during adolescence.