Physiological root resorption of primary molars.

Physiological root resorption of primary molars was assessed using bitewings and orthopantomograms. Thirty-six per cent of teeth examined demonstrated reduced root resorption of one or more roots. Excepting the lower first primary molar, the present study recorded a relatively high incidence of uneven root resorption during the exfoliative process, particularly evident for the upper second primary molar. Discrepancy in size between the premolar and its predecessor, as well as the position of the developing permanent tooth in relation to primary root structure influences the pattern of root resorption. Therefore, constant monitoring of teeth demonstrating uneven resorption is required to avoid the complications associated with over-retained teeth.