A cephalometric study to compare the effects of cervical traction and Andresen therapy in the treatment of Class II division 1 malocclusion. Part 1--Skeletal changes.

Lateral cephalometric radiographs at the beginning of treatment, end of active treatment, and post-treatment of 30 Andresen and 40 cervical traction patients were analysed, and compared with those of a control group of 22 untreated cases. The cervical traction group was divided into a non-extraction group and an extraction of maxillary second molars group. A clinically significant reduction of ANB was achieved, mainly by mandibular changes in the Andresen group and by maxillary changes in the cervical traction groups. Cervical traction was associated with a small distal positioning and anterior downward tipping of the maxilla during treatment. A more favourable sagittal position of the mandible was achieved in the Andresen group compared to the cervical traction groups, particularly the non-extraction group, where a greater transient backward rotation of the mandible occurred during treatment. A significant, but clinically small increase in mandibular body length occurred in Andresen patients compared to the control. However, in both treatment groups this was due to an increase in growth of the vertical ramus. The lower face heights, both anterior and posterior, increased in all groups, with the anterior upper face height also increasing in the cervical traction group.