El-Mangoury N H, Gaafar S M, Mostafa Y A
Angle Orthod. 1987 Jan;57(1):33-8. doi: 10.1043/0003-3219(1987)057<0033:MACAPD>2.0.CO;2.
A short-term longitudinal study of the role of mandibular anterior crowding in inflammatory periodontal diseases. Crowded dentitions show more periodontal involvement, and the improvement after scaling disappears more rapidly.