Mesial migration of lower molars in relation to facial growth and eruption.

Mesial migration of teeth in the buccal segments is a well recognised phenomenon in the human dentition. Its aetiology is not fully understood. It has been suggested that it is, to some extent, dependent on growth changes in the lower face. The purpose of this investigation was to examine mesial movement of first molars in the intact lower arch in relation to the amount and direction of facial growth and eruption of teeth. Mesial migration of lower first molars between 13 and 18 years was measured on 60 degrees cephalograms of 22 males and 29 females with intact lower arches. Correlation analyses were used to examine the relation between mesial migration and tooth eruption, growth changes in mandibular length and anterior face height and direction of growth. There was, on average, forward movement of first molars of 2.0-3.0 mm and eruption of 2.0-4.0 mm. No relation was found between forward movement of first molars and their eruption or the amount and direction of facial growth.