[Loss of molar anchorage: quantitative evaluation with a method of structural superposition]

The goal of this study is to analyze using structural cephalometric superimpositions the quantity of mesial molar drift in the maximum anchorage cases, with mainly extractions of the first four premolars. Molar anchorage is appreciated in cases treated with or without use of directional forces. The influence of various parameters: age, facial divergence, discrepancy and incisor repositioning, on the loss of anchorage is also evaluated. The statistical study called upon the test of Student for independent groups. A value of the risk of first species p<0.05 was considered as significant. The loss of anchorage seems less important with the use of the directional forces. On the other hand it is raised in teenagers and the cases of important incisor repositioning.