Objective To evaluate the change in mandibular second-molar (M2) angulation in orthodontic treatment with premolar extraction and lower third molar (M3). Study Design Panoramic radiographs were evaluated in 3 groups of 129 participants: (1) control, no orthodontic treatment (n = 65); (2) extraction, orthodontic treatment with premolar extraction (n = 30); and (3) nonextraction, orthodontic treatment without premolar extraction (n = 34). The angular difference and ratio of M2 to the first molar (M1), the change in the angulation of M2 between pre- and postorthodontic treatment, and the distal bone level of M2 were assessed. Results The angular difference and ratio of M2 to M1, the angulation change of M2 between pre- and postorthodontic treatment, and the distal bone level of M2 were higher in the nonextraction group than in the control and extraction groups. Conclusions The successful orthodontic alignment of the M2 may not be achieved in nonextraction cases when the M3s are present.
|Number of pages||6|
|Journal||Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology|
|Publication status||Published - 2014 Sep|
Bibliographical noteFunding Information:
This work was supported by the research fund of Yonsei University College of Dentistry for 2012 (6-2012-0089).
All Science Journal Classification (ASJC) codes
- Oral Surgery
- Pathology and Forensic Medicine
- Dentistry (miscellaneous)
- Radiology Nuclear Medicine and imaging