[Shape of dental arches and their dimensions in children without malocclusion aged 3 years]. / Ksztalt luków zebowych i ich wymiary u dzieci 3-letnich bez wad zgryzu.

The dental arches were analysed in 3-year-old children without malocclusion evaluating the shape of arches, measuring their with, length and depth. The index of the dental arch and the palatal index were calculated. In children aged 3 years the shape of the upper dental arch was in most cases similar to a semi-ellipse and that of the lower arch approached parabole. This suggests that the semicircular shape of dental arches is not characteristic of this period of occlusion development.

[Diastemata in 3-year-old children without malocclusion]. / Szpary miedzyzebowe u dzieci 3-letnich bez wady zgryzu.

In children aged 3 years without malocclusion the dental arches were studied for the occurrence, position and size of diastemata (interdental clefts). In the studied children most arches had diastemata (in 95% of cases in the upper arch and in 80% in the lower arch). It is concluded that the behaviour of the contact points between teeth is not a characteristic feature of the teeth of children aged 3 years. It seems that the presence of "closed" dental arches--without diastemata, and "open" with diastemata, confirms the presence of two types of dental arches of milk teeth.