Efstratiadis S S, Kent R L, Lebret L M, Moorrees C F
Angle Orthod. 1984 Oct;54(4):271-82. doi: 10.1043/0003-3219(1984)054<0271:SPOMTM>2.0.CO;2.
Measurement of anterior and medial inclinations of third molars from 10 to 18 years of age in monozygotic twins finds a consistent pattern of uprighting, with high correlations within twin pairs indicative of strong genetic influence.