Uprighting Severely Impacted Lower Second Molars Prior to Class II Correction with Upper Second-Molar Extractions

摘要

Although the prevalence of impacted mandibular second molars is less than 1%, the problem represents a major challenge to the orthodontist.1 The etiology of second-molar impaction can involve lack of space in the mandibular arch, early eruption of the third molars, loss of the first molars, alteration of the dental follicle, and other factors.2 The only viable alternative to extraction of the impacted molar is orthodontic relocation, the success of which depends on the anguiation and inclination of the impacted teeth and the positions of the adjacent third molars.