Clinical investigatory and analysis of the second molar malocclusions

Objective:To investigate the prevalence of the second molar malocclusions in orthodontic patients and analyze the correlated causative agents.Method:The samples consisted of 5,012 patients.Analysis was performed by their models and panoramic radiographs.Result:There are 2,067 patients with the second molar malocclusion in all 5,012 cases,and the prevalence is 41.24%.The main clinical manifestations are buccal malposition,deep overjet,palatoglossal malposition,torsional malposition and buccal crossbite.41.07%,46.88%and 12.5% in Class Ⅰ,Class Ⅱ and Class Ⅲ cases are with the second molar malocclusions.And there is 83.58% second molar malocclusion with the third molar existing in the same quadrant.Conclusion:The second molar malocclusion occurs with the third molar exiting in the same quadrant.And with the high prevalence we should pay attention to these situations.