Abstract
Four cases of eruption failure of the first permanent molar were clinically examined for their causes and treatment of choice, course and duration.
1) The age of the patients ranged from 7 years 11 months to 9 years 6 months when diagnosed.
2) In all cases, there were existing masses above or around the crown of the impacted first permanent molars, that were considered to be related to eruption failure; they were diagnosed clinically or histopathologically as tooth-like structures, complex odontoma, compound odontoma and ameloblastic fibro-odontoma, respectively.
3) In three cases, the fenestration was made including the removal of the surrounding bone of the impacted tooth crown after a certain period from the initial treatment of the surgical removal of the causative masses, and the impacted first permanent molars successfully erupted thereafter. In another case, traction was tried as a treatment of choice 4 months after initial treatment composed of the surgical removal of the causative masses, but was discontinued after 3 months without the expected result. The impacted tooth, however, finally erupted after an additional observation period of one year.
4) Eruption guidance was successfully completed in all cases and the duration of guidance ranged from 7 months to one year and 7 months.
