Changes in occlusal relationships in mixed dentition patients treated with rapid maxillary expansion
McNamara Jr, James A., Sigler, Lauren M., Franchi, Lorenzo, Guest, Susan S., Baccetti, Tiziano
1 Mar 2010
March 2010
The Angle Society
The Angle Orthodontist
80
2
230-238
10.2319/040309-192.1
Changes in occlusal relationships in mixed dentition patients treated with rapid maxillary expansion
<p>Objective: To prospectively measure occlusal changes in mixed dentition patients who underwent a standardized early expansion protocol. Materials and Methods: The treatment sample consisted of 500 patients who were assigned to three groups according to molar relationship: Class I (n = 204), end-to-end (n = 166), and Class II (n = 130). All patients were treated with a bonded rapid maxillary expander (RME) followed by a removable maintenance plate and a transpalatal arch. Mean age at the start of treatment was 8.8 years (T1), with a pre–phase 2 treatment cephalogram (T2) taken 3.7 years later. The control sample consisted of the cephalometric records of 188 untreated subjects (Class 1, n = 79; end-to-end, n = 51; Class II, n = 58). Results: The largest change in molar relationship was noted when the Class II treatment group (1.8 mm) was compared with the matched control group (0.3 mm). A positive change was seen in 81% of the Class II treatment group, with almost half of the group improving by ≥2.0 mm. The end-to-end treatment group had a positive change of 1.4 mm, compared with a control value of 0.6 mm, and the Class I group of about 1 mm compared with controls, who remained unchanged (0.1 mm). Skeletal changes were not significant when any of the groups were compared with controls. Conclusion: The expansion protocol had a significantly favorable effect on the sagittal occlusal relationships of Class II, end-to-end, and Class I patients treated in the early mixed dentition.</p>
Published
McNamara, James A. Jr. DDS, MS, Ph.D.
Tagged: Journal Article
posted by Shakir, Sheba
