CLASS-III MALOCCLUSION IN THE DECIDUOUS DENTITION - A MORPHOLOGICAL AND CORRELATION STUDY

The craniofacial morphology of Class III children with a full deciduou s dentition was investigated by means of a cephalometric and correlati on study. A group of 69 Class III subjects was compared to a group of 60 Class I subjects during the phase of the primary dentition. Each gr oup was then divided into three age subgroups (4, 5, and 6 years) and a comparison was also performed between Class III and Class I subgroup s. According to the results, early signs of Class III skeletal disharm ony are present during the deciduous dentition phase. A larger mandibu lar body length (P<0.001), a greater value for the ratio between the e xtent of the anterior cranial base and the mandibular body length (P<0 .001), and a forward positioning of the mandible (<P0.01<0.001) were c onsistently found in Class III children at the ages of 4, 5, and 6 yea rs. A correlation analysis between all the cephalometric measurements in the Class III and Class I groups was then carried out, and the sign ificance of the differences between correlation coefficients of the tw o groups was calculated. A distinctive Class III pattern of non-topogr aphical associations between anterior cranial base and mandibular meas urements could be detected.