[A new technique for the treatment of ectopically erupting permanent first molars]

The problem and treatment of the ectopically erupting permanent first molars have been addressed by many authors since they were first mentioned in the literature by Chapman in 1923. Many treatments involve techniques using the primary second molar. It is better for correcting the eruption of the permanent first molar into normal occlusion to maintain the primary second molar in its normal position. However severe mobility and root resorption are often present when an ectopic eruption is found. An 8-year-old male with ectopic eruption of the maxillary right permanent first molar was examined and treated. The right primary second molar demonstrated severe mobility and root resorption, and therefore a new appliance using the primary first molar was designed. After 4 months from the beginning of the treatment the mobility of the primary second molar decreased, and after 6 months the permanent first molar almost erupted in its normal position.