Background:

Midface hypoplasia is a common finding in patients with syndromic craniosynostosis. Typically, midface hypoplasia is treated with a Le Fort III (midface) advancement.

 Objectives:

To examine the long term midface skeletal stability and growth following Le Fort III midface advancement in growing children (<12.5 years).

 Methods:

A review of 192 patients with syndromic craniosynostosis treated with a conventional Le Fort III advancement between 1973 and 1998 was performed. A total of 25 patients met the inclusion criteria: age at surgery of less than 12.5 years and cephalograms of diagnostic quality at pretreatment, post surgery, 1, 5 and 10 year follow-up. There were 11 males and 14 females. At the time of surgery, mean age was 5.8 years (range 3.8 to 12.5). Fifty two cephalometric anatomic landmarks were identified and digitized at each of the five time intervals (Dolphin imaging software). The X and Y displacement of each cephalometric landmark was serially examined.

 Results:

Immediately following midface advancement, point A advanced sagittally along the X axis an average of 10.72 mm and moved inferiorly an average of 3.62 mm along the Y axis. At one year, point A moved forward sagittally an average of 0.10 mm, and inferiorly an average of 0.47 mm. At 5 and 10 years following surgery, point A remained stable at -0.18 mm and 0.12 mm, respectively. During the same period, however, pogonion came forward an average of 5.72 mm and 7.32 mm, respectively.

Conclusion: The position of the Le Fort III midface segment in growing children with syndromic craniosynostosis is stable at one year following surgery. However there is minimum antero-posterior midface growth between postoperative years 5 and 10, whereas mandibular growth continues normally. Due to the average differential midface and mandible growth rates, the profile of patients in our study becomes concave, and they develop an anterior crossbite. Ultimately, these patients require secondary midface surgery at the completion of skeletal growth.