Preferred Abstract (Original):
Background
Though the foramen magnum (FM) is often altered in complex
craniosynostosis, no study analysed the FM dimensions in patients with
brachycephaly specifically.
Patients and methods
We measured the FM area, sagittal and transverse diameters on preoperative
CT scans in patients with bicoronal synostosis (n = 40)
and age-matched control group (n = 18). Our
study included 16 children with FGFR3 p.Pro250Arg mutation (mean age
6.1 months), 10 with TWIST-1 mutation (mean age7.6 months) and 14
patients with isolated bicoronal synostosis (mean age 6.1).
Results
We observed a significantly smaller FM area in FGFR3 group compared to
control group and isolated brachycephaly group (p = 0.001
and p = 0.038, respectively). The mean
FM area in FGFR3 group was 426.13 mm2 (p = 0.001), while in TWIST-1 group
was 476.34 mm2 (p = 0.103), and
in isolated brachycephaly group 489.43 mm2 (p = 0.129) compared to control
group: 528.90 mm2. The posterior segment of the sagittal
diameter of the FM and its width as well as the bi-interoccipital synchondrosis
diameters were significantly smaller in FGFR3 group compared to control group.
In TWIST-1 group, the only altered dimension was the FM anterior segment of the
sagittal diameter (p = 0.008). We did not observe any
significant alteration of FM in patients with isolated brachycephaly compared
to control group.
Discussion and conclusions
The FM area is significantly altered in FGFR3-related
brachycephaly, whereas in patients with Saethre–Chotzen syndrome (TWIST-1
mutation) the mean FM area is similar to control group. This study confirms the
importance of FGFRs on FM growth whereas TWIST-1 seems to have a minor role.