Corrected Cephalometric Analysis and hybrid Osteogenesis Distraction System to Control the Distance and Vector with Le Fort III Osteotomy for Syndromic Craniosynostosis

Background: The purpose of this study was to confirm the utility of corrected cephalometric analysis to facilitate the planning of distraction osteogenesis with Le Fort III osteotomy for syndromic craniosynostosis, and to evaluate the stability and/or resultant change in facial features after at least 1 year of follow-up (range, 1-9 years).

Methods: This prospective study involved 8 cases of Crouzon syndrome and 3 cases of Pfeiffer syndrome (types II and III) (age range, 4 years 6 months to 13 years 2 months) treated with primary Le Fort III maxillary distraction using corrected cephalogram analysis and a hybrid distraction system. Corrected cephalogram analysis involves superimposing a patient’s cephalogram onto that of a normal Japanese adult. Both cephalograms are then superimposed using the articulare for guidance to determine the distance and vector of distraction osteogenesis. The hybrid distraction system is composed of both a conventional external distraction device and a newly developed adjustable-angle internal distraction device. Postoperative control of the distraction vector is performed by pulling the midfaces using the external device, while control of distraction distance is done by pushing the midfaces with the internal device.

Result: Midfaces were brought close to the planned position from the corrected cephalometric analysis in Crouzon syndrome. Midfaces were advanced by 19.8±4.0 mm at Or and 29.4±4.1 mm at point A, but accurate alignment to the planned vector was difficult. Meanwhile, midfaces were not brought close to the planned position from the corrected cephalometric analysis in Pfeiffer syndrome. Midfaces were advanced by 32.0±2.1 mm at Or and 34.7±5.0 mm at point A, but accurate alignment to the planned vector was more difficult for Pfeiffer than for Crouzon. Facial features changed little on follow-up, 1-9 years after removal of the distraction device.

Discussion: Pfeiffer syndrome was more difficult than Crouzon syndrome to achieve results close to the planned position. This was because severe Pfeiffer syndrome requires advancement over a longer distance than Crouzon syndrome, and the nasal part of the soft tissue might be tighter in Pfeiffer syndrome than in Crouzon syndrome.

Conclusions: Using corrected cephalometric analysis, the distance and vector of distraction osteogenesis with Le Fort III osteotomy could be determined in patients with syndromic craniosynostosis. This distraction system offers the possibility of brining facial bones to the planned position using controlling devices. However, final long-term growth remains unclear.

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