Classification of mandibular shift by cluster analysis

Abstract

There are several varieties of mandibular shift. We attempted to classify mandibular shift cases that had mandibular protrusion, using frontal cephalograms and plaster models of the dentition. We measured indexes on cephalograms and oral models, and applied cluster analysis and statistical correlation. We found four groups of mandibular protrusion cases with mandibular shift, and applied correlation analysis to each group. Classified groups are fllowing. Group 1 is that Menton related with the position of the maxillary molars. Group 2 is that Menton related with few measurement index. Group 3 is that Menton related with AG line angle and Mo line angle. Group 4 is that Menton related with AG line angle. And AG line angle related with Zyg line angle, MX line angle, Cd line angle. We found that cases with mandibular shift could be categorized by cluster analysis and correlation analysis.