Skeletal changes after midface surgery in patients with craniofacial deformities: a three-dimensional quantification method.

To determine the skeletal changes after midface surgery in patients with syndromic craniosynostosis who underwent Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB). This was a retrospective study including 75 patients: 33 treated by LFIII, 29 by MB, and 13 by FB. Twenty-five had a diagnosis of Apert, 39 Crouzon, and 11 craniofrontonasal syndrome. A three-dimensional mesh was created from the preoperative scan and registered to the postoperative scan to visualise the advancement. LFIII at age 7-12 years effectuated a higher mean advancement in the maxillary (15.5 mm) and zygomatic (7.6 mm) regions when compared to ≥13 years (10.2 mm and 5.5 mm). After MB, mean advancement of the fronto-orbital region was higher at <7 years (16.4 mm), and similarly lower at ages 7-12 (13.8 mm) and ≥13 (12.5 mm). The mean preoperative inter-dacryon distance (34.4 ± 4.4 mm) was reduced by 8.7 ± 4.2 mm after FB without distraction (n = 10). More advancement was seen when midface surgery was performed at a younger age, due to more severe cases and a desire for overcorrection. The highest mean advancement was observed in the fronto-orbital region. Antero-inferior rotational movement was seen after all three techniques.