Abstract
Purpose：A cross-sectional study was performed to clarify the relationship between mandibular anterior crowding and gingival
recession in adult patients aged over 40 years．
Methods：Data was included the mandibular anterior crowding, bleeding on probing（BOP）, pocket depth（PD）, clinical attach-
ment loss（CAL） from 55 patients over 40 years who started orthodontic treatment, except smokers, diabetes, and other general
diseases.
Results：There was a significant difference （P=0.0000371） in gingival recession between the group with over 5 mm and less
than 5 mm. There was a correlation between the amount of gingival recession and the amount of crowding （Spearman correla-
tion coefficient 0.528）.
Conclusion：This study suggests adults mandibular anterior crowding may be one of the causes to happen gingival recession at
the same site．
