An assessment of surgical and 10-year follow-up vertical changes after contemporary Class II and III orthognathic surgery

Abstract

There has been little quantification of long-term vertical facial changes that might occur after contemporary orthognathic surgery. The aim was to assess ≥10-year follow-up vertical facial changes in patients after Class II and III orthognathic surgery. Sequential lateral cephalograms of 162 former orthognathic patients had been gathered during routine clinical follow-up before any consideration was given to this current project. For this study, facial patterns were classified according to the Frankfort-mandibular plane and ANB angles and the horizontal distance from the pogonion to the nasion-perpendicular line. Chosen Class II and III groups were divided into longer and shorter-face subgroups on either side of the average FMP angle (longer face>25°). The assessment was made from already-available lateral cephalograms taken before treatment, at debanding, and ≥10-year clinical follow-up. After obvious improvement with orthodontics and orthognathic surgery, mean FMP angles seemed to move back toward the preexisting vertical dimensions in both Class II and III longer and shorter-face groups over the next decade. However, there was considerable individual variation around the means. Similar posttreatment changes were seen with the ANB angle and the distance from pogonion to the nasion-perpendicular line. Significant correlations were found between the amount of preexisting discrepancy for these variables and their changes during and after treatment. Significant planned vertical mandibular changes are achieved with Class II and III surgery. However, in the longer term, it would seem that, in general, there is a tendency for postsurgical vertical facial proportions to revert somewhat toward the pretreatment proportions. Wide individual variation in posttreatment musculoskeletal behavior should be expected. Despite these changes, it does not necessarily mean that there should be an expectation of long-term dentofacial collapse after such treatment.