Eruption speed and rate of angulation change of a cyst-associated mandibular second premolar after marsupialization of a dentigerous cyst.

The purpose of this study was to investigate the eruption speed and rate of angulation change of a cyst-associated mandibular second premolar after marsupialization of a dentigerous cyst in preadolescents. Premolars on the cyst and noncyst sides and size of the cyst were retrospectively examined with a total of 42 pairs of normalized panoramic radiographs in 20 patients who underwent neither extraction nor orthodontic traction of the cyst-associated mandibular second premolar after marsupialization. Sixteen premolars at the intraosseous eruption stage in a total of 9 preadolescents without cysts were also examined. The eruption speed and rate of angulation change of the cyst-associated mandibular second premolar were significantly faster than those of the premolars without cysts, and significantly correlated with the diminishing rate of the cyst size, which rapidly decreased for the first 3 months after marsupialization. In addition, the eruption speed of the cyst-associated mandibular second premolar correlated with that of the premolar on the noncyst side, and the rate of angulation change inversely correlated with the level of root formation. The results suggest that a cyst-associated permanent tooth erupts more rapidly regardless of the level of root formation and size and type of the cyst, and the abnormally tilted tooth axis improves more rapidly for the first three months after marsupialization of a dentigerous cyst in preadolescents.