Long-term changes in skeletal and airway dimensions in patients treated with headgear compared with untreated control subjects.

INTRODUCTION: The objective of this study was to evaluate the short-term and long-term skeletal and airway changes associated with the use of headgear and to compare these changes to a group of untreated control subjects. METHODS: The sample included 2 Class II groups: a group treated with cervical headgear and a group of untreated control subjects, with 30 subjects in each group. Lateral cephalograms were taken at 3 time points: pretreatment (T1), posttreatment (T2), and long-term postretention (T3), and a single examiner performed skeletal and airway measurements. Paired samples t test was used to compare T1, T2, and T3 skeletal and airway measurements within the groups, and independent samples t test was used to compare treatment (T2 - T1), posttreatment (T3 - T2), and overall (T3 - T1) skeletal and airway changes in the treatment group compared with the control group. RESULTS: There was a significant decrease in the SNA (3.1 degrees ) and an increase in the SN-PP (1.5 degrees ) in the treatment group at T2 (P <0.001), which remained significant at T3 (P <0.05). In addition, there was a significant short-term increase in the mandibular plane angle and a decrease in SNB (P <0.05). Paired t tests showed no significant change in airway width within the treatment group (P >0.05). The independent samples t test showed no significant differences in any of the changes in airway variables between the groups (P >0.05). CONCLUSIONS: The use of headgear did not result in any change in airway width, both short-term and long-term. A decrease in SNA and an increase in SN-PP were found with the use of the headgear, and these changes remained stable for up to 8 years posttreatment.