Long-term stability of surgical open-bite correction by Le Fort I osteotomy.

Skeletal changes greater than those observed in untreated adults have been noted beyond 1 year post-surgery in adult patients who had surgical correction of a long face deformity. The stability of skeletal landmarks and dental relationships from 1 to >3 years post-surgery was examined in 28 patients who had undergone surgery of the maxilla only, and in 26 patients who had undergone 2-jaw surgery to correct >2 mm anterior open bite. Although the average changes in almost all landmark positions and skeletal dimensions were less than 1 mm, point B moved down >2 mm and face height increased >2 mm in one-third of the maxilla-only group and in 40% of the 2-jaw group (>4 mm in 10% and 22% respectively). Overbite decreased 2-4 mm in only 7% of the maxilla-only and 12% of the 2 groups, with no changes >4 mm, because in three-fourths of the patients with an increase in anterior face height, further eruption of the incisors maintained the overbite relationship. In the maxilla-only group, mandibular length (Co-Pg) showed >2 mm long-term change in 45% of the patients, two-thirds of whom showed an increase rather than a decrease in length. In the 2-jaw group, no patients showed a decrease in Co-Pg length and one-third had an increase. For both groups, changes in overjet were smaller and less frequent than changes in mandibular length.