Further observations on lower third molar tilt

The angulation of lower third molars on opposite sides of the jaw was compared on 50 orthopantographic radiographs of children who had mesial migration of lower first permanent molars on one side only following unilateral extraction of lower second deciduous molars. On 36 films the lower third molar was less tilted on the extraction side. Applying a paired t-test this difference is significant (p less than 0.001). The distance of mesial migration was estimated, and the findings are discussed in relation to the hypothesis that early mesial migration of posterior teeth reduces the tilt of lower third molars.