POSTERIOR CROSS-BITES IN DECIDUOUS AND MIXED DENTITIONS

In this study, 515 children 3 to 9 years of age were examined and forty were found to have posterior cross-bite in the deciduous or mixed dentition, for an over-all prevalence of 1:13 or 7.7 per cent. It was evident from the observations of treated and untreated cases that posterior cross-bite is not self-correcting, that untreated deciduous-dentition cross-bite is followed by mixed-dentition cross-bite, and that treatment of deciduous-dentition cross-bite favors development of normal occlusion in the mixed dentition. The diagnosis of unilateral and bilateral cross-bite remains largely empirical in the absence of reliable reference points for determining the correct lateral position of the mandible. The use of interincisal midlines for this purpose is questioned. © 1969.