Does impacted lower third molar exert a forwardly directed pressure?

Background and objectives: Impacted lower third molar has been blamed for lower incisor crowding. The aim of this study was to measure the amount of pressure exerted by lower third molar. Method: The study was conducted on 62 patients who underwent surgical removal of impacted lower third molars. The mean age of the subjects was 25.4 years with a range of 18-37 years. Interdental frictional strength was measured between posterior teeth, before and one week after lower third molar removal, using 0.05 mm stainless steel strip and digital force gauge. Results: No significant difference was noted in interdental frictional strength before and after lower third molar removal. The depth of impacted lower third molar and proximity of impacted tooth to the adjacent second molar has no significant influence on the interdental frictional strength. Conclusion: Impacted lower third molar does not exert any significant force on the teeth and should not cause lower incisor crowding.