Cardinal features of the syndromic cranial synostosis are:
- midface hypoplasia
- forehead retrusion
Most of these patients have bicoronal synostosis but multiple cranial sutures in different combinations may also be involved.
Most children therefore undergo frontal/superior orbital rim advancement in infancy with repeat advancement as needed. For the midface deformity, a Le Fort III or monoblock osteotomy is required.
The "standard" Le Fort III osteotomy is performed when the superior orbital rim and forehead are in a satisfactory position and it is only the midface that requires advancement.
A monoblock osteotomy done transcranially is utilized when the forehead, orbits, and midface all require a similar magnitude of advancement.
The Le Fort III osteotomy using conventional fixation and bone grafts is usually performed after craniofacial growth is complete, although some proponents do it during the period of growth.
More often the Le Fort III osteotomy is done via distraction osteogenesis in the younger patients in order to overcorrect the deformity, reduce complications, obviate the need for bone grafts, and hopefully reduce the total number of operations the child might need.
The conventional monoblock osteotomy can also be done as a single stage or via distraction in children up to age 6-8 years. Single stage advancements are not often done after this age due to the excessive risk of complications (infections, CSF leak, etc.).