[Spontaneous correction of the rotation of the permanent central lower incisors]

On the basis of a series of dental models from children between five and nine years (twice-yearly examination) with final models being made of 319 of these children at the age of 16, determinations were made of the rotation of the permanent central lower incisors 'shortly after complete eruption of the cutting edge' at the age of 16. The study showed that spontaneous correction amounts to 53% and 60% respectively for an original mesio-lingual rotation (type less than 90 degrees) and for an original disto-lingual rotation (type greater than 90 degrees).