THE RELATED-FACTORS OF MALOCCLUSION OF LOWER SECOND PERMANENT MOLARS

Objective To investigate the types of malocclusion of lower second permanent molars and their related factors,in order to provide a reference for orthodontic procedure.Methods This study was conducted in 105 patients who met the orthodontic requirement,their models and panoramic radiographs were measured,recorded and analyzed.Data obtained were analyzed by software SPSS 13.0.Results The rate of the lower second permanent molar malocclusion was 40.95%.Thelower second permanent molar malocclusion was significantly correlated with the width of lower alveolar arch at the lower second molarlevel,deficiency in space of posterior lower alveolar arches and the classification of Angle Ⅱ malocclusion(OR=4.621,0.745,0.914;P0.01,0.05).However,the malocclusion of the lower second permanent molars was not correlated with the width of lower alveolar arch at the lower first molar level,lower third molar and classification of Angle Ⅲ malocclusion(P0.05).Conclusion Clinically,the width of lower alveolar arch and the space of posterior lower alveolar arches should be considered in malocclusion correction.