Long-term maxillary behavior in treated skeletal class II malocclusion

ABSTRACT

Aim: To evaluate the post-treatment and long-term anteroposterior and vertical maxillary changesfrom the use of Kloehn cervical headgear in treated skeletal Class II Division 1 malocclusion.Methods: Using a longitudinal prospective study design, 90 lateral radiographs of 30 treatedpatients (12 male gender and 18 female gender) were taken at the beginning of the treatment (meanage = 10 years and 9 month), at the end of the treatment (mean age = 14 years and 6 months), andin the post-retention phases (mean age = 26 years and 2 months). Lateral radiographs of 30 adultspatients with Class II malocclusion, as control group (mean age = 24 years and 1 month) werecompared with lateral radiographs of patients in the post-retention phase in order to quantify thecephalometric measurements (5 angular and 2 linear) representing the maxillary position in theanteroposterior and vertical direction. Results: Under the effect of treatment, forward displacementof the maxilla was redirected in a downwards and backwards direction. When the means of thefemale measurements were compared between the two groups, only ANB was greater in the controlgroup. When the male measurements were compared, they presented a mean value of ANBgreater in the control group, and the mean of SNPP greater in the treated group. Conclusions: Inthe post-retention phase, maxillary displacement reverted in a downward and forward direction,confirming the transitory effect of the extra-oral action on maxillary displacement.