We encountered a patient with the completely impacted upper second premolar and completely impacted lower first molar with a follicular dental cyst, which were moved to normal dentition position by surgical and orthodontic treatment.
The patient was a 10-year-old boy, who was brought to our department with a chief complaint of delayed eruption of 6_??_, showing trasmissive X-ray images, in 6_??_, on December 8, 1999. Intra-ral findings showed that ED_??_were missing, part of the tooth crown of 5_??_erupted, and the second premolar was unerupted.
ED_??_were remaining, and 76_??_were unerupted. By panoramic X-ray, 5_??_was bucco-lingually impacted, and 6_??_was impacted in a low position with a slight mesial inclination, showing transmissive X-ray images containing the tooth crown of 6_??_. In January 2000, the cyst in 6_??_was excised, and fenestration was performed under local anesthesia. On the fifth month after fenestration, it was confirmed that 6_??_started to slightly move in the direction of the tooth crown. Since part of the tooth crown of 6_??_between 7_??_and 5_??_was confirmed approximately 1 year thereafter, after leveling 75_??_, and bending an over wire in which an open coil spring was incorporated using 0.16 and 0.18 round wires, 7_??_was distally moved, and a space for the eruption of 6_??_was maintained. Although the tooth crown of 6_??_was confirmed 2 months thereafter, since mesial inclination was marked, 6_??_was moved to almost the normal position by guiding with slight traction after placing brackets. Conventional orthodontic treatment was then performed to establish Class I occlusal relationship, with a combined used of Class II elastic. Two years after the first examination, although X-rays showed a slightly curved tooth root, a good stability of 6_??_in the jaw bone was obtained.
On the other hand, after fenestration in 5_??_, a plate was placed to maintain a space for the eruption of 5_??_. After observing the clinical course for approximately 10 months, 5_??_started to rotate in the normal eruptive direction, and when placement of brackets became possible approximately 1 year after, 5_??_showed the same condition as that of the normally erupted teeth. It is considered that after completing dynamic orthodontic treatment, a long-term course observation is necessary.
