Even if the pathogenesis of nonsyndromic sagittal craniosynostosis is univocal (i.e., premature fusion of the sagittal suture) and the deformation of the skull follows the Virchow rules, there are different skull shapes in scaphocephaly. The mechanism of deformation and sutural compensation is explained in part by Delashaw et al.,1 who refined the Virchow rules, but these authors did not explain the variability of the skull deformation secondary to premature fusion of the sagittal suture. Several explanations are possible, such as the timing of onset in utero, the site of initial fusion, the progression of the fusion, and the compensatory responses of unfused sutures to the continually growing brain. The variability of intracranial pressure in the nonsyndromic unique suture craniosynostosis2 may also be a factor responsible for the variability in skull shape seen in scaphocephaly. Thus the true explanation is unknown.
Schmelzer et al.3 stated that the spectrum of cranial dysmorphology of scaphocephaly has not been considered in any surgical outcome studies to date, but that is not completely correct. Jane and Francel4 described three patterns of calvarial surface dysmorphology in response to the site of the sagittal sutural fusion (anterior sagittal synostosis, posterior sagittal synostosis, and complete sagittal synostosis) and four degrees of severity. They modified and adapted their surgical procedure in relation to one of the 12 possibilities to improve their cosmetic results. So in the literature, the spectrum of skull dysmorphology, especially the calvaria, is also variable and not consensual. Schmelzer et al.3 showed four specific patterns of calvarial surface dysmorphology: bifrontal bossing, bitemporal protrusion, coronal constriction, and occipital protuberance. Montaut and Stricker5 observed two major patterns of skull dysmorphology in nonsyndromic sagittal craniosynostosis: sphenocephaly with a bifrontal bossing and leptocephaly with a bifrontal narrowing. Recently, my colleagues and I performed a morphometric retrospective study of calvarial dysmorphology using 42 three-dimensional computed tomography scans of nonsyndromic sagittal craniosynostosis.6 We observed, as did Montaut and Stricker, two major patterns of calvarial dysmorphology, bifrontal bossing (Fig. 1, above) and bifrontal narrowing (Fig. 1, below), with significantly different occipital deformation. In frontal narrowing, the squamous part of the occipital is rotated more backward and downward than in frontal bossing, and the metopic sutural adaptation seems to be impaired. For each group, we observed three subpatterns of calvarial surface dysmorphology: retrocoronal striction, prelambdoid striction, and the absence of striction (harmonious calvarial shape). So, in our morphometric study, my colleagues and I defined six specific patterns of calvarial surface dysmorphology (Fig. 1).
In conclusion, preoperative recognition of the calvarial dysmorphology in nonsyndromic sagittal craniosynostosis is necessary to adapt the operative technique and improve the overall result. Currently, however, the definition of calvarial dysmorphology in scaphocephaly and the best surgical procedure have not been clearly established.
Guillaume Captier, M.D.
Service de Chirurgie Plastique Pédiatrique
Montpellier F-34000, France
1. Delashaw, J., Persing, J., Broaddus, W., and Jane, J. Cranial vault growth in craniosynostosis. J. Neurosurg.
70: 159, 1989.
2. Renier, D., Sainte-Rose, C., Marchac, D., and Hirsch, J. Intracranial pressure in craniostenosis. J. Neurosurg.
57: 370, 1982.
3. Schmelzer, R. E., Perlyn, C. A., Kane, A. A., Pilgram, T. K., Govier, D., and Marsh, J. L. Identifying reproducible patterns of calvarial dysmorphology in nonsyndromic sagittal craniosynostosis may affect operative intervention and outcomes assessment. Plast. Reconstr. Surg.
119: 1546, 2007.
4. Jane, J., and Francel, P. The evolution of the treatment for sagittal synostosis: A personal record. In J. Goodrich and C. Hall (Eds.), Craniofacial Anomalies: Growth and Development from a Surgical Perspective.
New York: Thieme Medical, 1995. Pp. 15-22.
5. Montaut, J., and Stricker, M. Dysmorphies Craniofaciales: Les Synostoses Pématurées.
Rapport 27e Congrès sdndlf. Paris: Masson, Médecine, 1977.
6. Captier, G., Bigorre, M., Rakotoarimanana, J., Leboucq, N., and Montoya, P. Etude des variations morphologiques des scaphocéphalies: Implication sur leur systématisation. Ann. Chir. Plast. Esthet.
50: 715, 2005.
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