6Witsenburg B, Boering G. Eruption of impacted permanent upper incisors after removal of supernumerary teeth [J].Int J Oral Surg, 1981,10(6):423-431.
7Bullen C, Saravia ME, Steinberg B. Conservative mangenent of an impacted incisor [J]. Oral Surg Oral Med Oral Pathol,1986,61(6): 564-567.
8Kohavi D, Becker A, Zilberman Y. Surgical exposure,orthodontic movement,and final tooth position as factors in periodontal breakdown of treated palatally impacted canines [J].Am J Orthod, 1984,85:72-77.
9Vanarsdall RL, Corn H. Soft-tissue management of labially positioned unerupted teeth[J]. Am J Orthod Dentofac, 2004, 125: 284-293.
