Secular trends affect timing of emergence of permanent teeth.

CONCLUSION:   The longer duration of mixed dentition in group 2000 than in group 1980 makes the duration of combined follow-up and active treatment longer, and should be considered in timing of efficient orthodontic treatment.
PMID: 25923246 [PubMed - as supplied by publisher]

Source: The Angle Orthodontist - April 29, 2015 Category: Dentistry Authors: Eskeli R, Lösönen M, Ikävalko T, Myllykangas R, Lakka T, Laine-Alava MT Tags: Angle Orthod Source Type: research