A long-term, follow-up, radiographic evaluation of asymptomatic impacted third molars in orthodontically treated patients.

Long-term follow-up orthopantomographs of 251 adult orthodontically treated former patients showed 113 clinically asymptomatic impacted third molars in 58 patients. Radiographic assessment revealed contact of impacted third molars with the second molars, resorption of maxillary and mandibular second molars, as well as pathologically widened pericoronal spaces of the maxillary and mandibular third molars. The comparison of the sagittal third molar position in 52 impacted teeth revealed a sagittal change in all third molars from post-treatment to follow-up: maxillary and mandibular third molars had rotated to a more upright position and showed an increase in mesio- or distoangulation or a change of axial inclination. The lack of predicting factors such as age, period of impaction, extent of space deficiency, developmental stage, level of eruption, and bone conditions leads the authors to recommend that former orthodontic patients be recalled at regular intervals for assessment of changes in the condition and position of erupting or impacted third molars.