Tooth morphology in Down's syndrome: evidence for retardation in growth

Two dental morphological features, lower incisor shape and Carabelli trait on upper molars, were studied in Down's syndrome (DS) individuals and control groups. Lower incisors were smaller in DS in absolute terms, but showed a relatively greater mesiodistal crown dimension than labiolingual, the opposite relationship to normal. Although the Carabelli trait was present in a high percentage of DS subjects, few showed the cuspal form. These findings are consistent with the concept of a reduction of cellular activity of tooth germs reflecting a general retardation in growth in DS. The altered shape of the lower incisors may influence the pattern of periodontal disease observed in DS subjects.