Investigation of Impacted Permanent Teeth Except the Third Molar in Chinese Patients Through an X-Ray Study

Purpose: To investigate the incidence and the local factors of impacted permanent teeth except for the third molar, in Chinese patients through an x-ray study. Materials and Methods: A total of 548 impacted permanent teeth from panoramic radiographs were studied and recorded according to the patients' gender and age, tooth position, and classification of impaction. The local factors contributing to impacted permanent tooth were also investigated. Results: The incidence of impacted permanent teeth in the Chinese was 6.15%. The impacted tooth showed a predilection for women and was more common in the maxilla. The impaction of the canine had the greatest occurrence, 28.10% of all impacted teeth. Vertical impaction was most common (49.09%). The chief local factor for impacted teeth was the lack of interdental space (49.64%). Conclusions: All permanent teeth can occur with impaction in Chinese patients. Dentists should perform a thorough evaluation before planning suitable treatment. (C) 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 68:762-767, 2010