The sequence of eruption of the permanent dentition in a Chilean sample with Down's syndrome.

The eruption of the permanent teeth in Down's individuals is reportedly delayed. The extent of such delay in comparison to normal children has been little studied. The eruption characteristics of the permanent teeth in a sample of Chilean individuals with Down's syndrome were here compared with those of the normal Chilean population. The sample consisted of 240 Down's individuals (all with trisomy 21), 116 males and 124 females. The chronological sequence of eruption in Down's children was not completely different from the normal. The least affected teeth were upper and lower first molars and central and lateral incisors. Alterations of the eruption sequence were not necessarily a consequence of alterations in the time of eruption. Asymmetries between sides of the jaw were mainly in canines and premolars. Alterations in sequence timing and asymmetry seem to be age dependent, being less frequent between 7 and 9 yr of age and more frequent between 10 and 14 yr of age. This may also reflect the larger variances of age of eruption observed in Down's individuals. Despite this, Down's children maintained a certain similarity in sequence and symmetry in comparison to normals.