2015 HSC Section 1 Book of Articles

premature suture closure causes predictable restric-

tion and compensatory growth was developed by

Virchow [6]. According to Virchow’s law, premature

suture fusion results in decreased growth perpen-

dicular to the suture and increased compensatory

growth parallel to it. The predictable clinical phe-

notypes of single suture synostoses are as follows.

Metopic craniosynostosis results in trigonocephaly,

a keel-shaped deformity with midline forehead ridg-

ing, and narrowed bitemporal distance (Fig. 1). Sag-

ittal craniosynostosis causes scaphocephaly, a long

‘boat-shaped’ head with narrowed interparietal dis-

tance and compensatory lengthening in the anterior

posterior dimension (Fig. 2). Unilateral coronal syn-

ostosis results in anterior plagiocephaly character-

ized by recession in the ipsilateral forehead; there is

accompanying displacement of the ipsilateral

superior orbital rim towards the synostotic suture,

known as the ‘harlequin deformity’ (Fig. 3). There is

compensatory contralateral forehead bossing and a

subsequent inferior displacement of the contrala-

teral superior orbital rim. Predictable facial deform-

ities also accompany unilateral coronal synostosis:

the nasion is deviated ipsilaterally, the ipsilateral

zygoma is displaced anteriorly and the chin point is

displaced to the contralateral side. Bilateral coronal

synostosis is more often associated with craniosy-

nostosis syndromes (Fig. 4). The resulting deformity

is brachycephaly, or short head. There is shortening

in the anterior–posterior dimension, bilateral reces-

sion of the superior orbital rims and excessive height

of the anterior forehead.

Lambdoid synostosis is the rarest form of syn-

ostosis, and can be mistaken for deformational pla-

giocephaly. In true synostosis, there is ipsilateral

occipital flattening, compensatory bulging of the

contralateral occiput, and a deviation of the petrous

temporal bone toward the offending suture, causing

the external ear to be malpositioned posteriorly

(Fig. 5). The head assumes a trapezoidal shape

viewed from above. In deformational plagiocephaly,

there is ipsilateral occipital flattening, but ipsilateral

frontal bossing and contralateral frontal flattening,

creating a parallelogram shaped head without defor-

mation of the cranial base.

In the last 15 years, we have expanded our

knowledge of the genetics of craniosynostosis.

KEY POINTS

The treatment of nonsyndromic craniosynostosis begins

with the proper diagnosis. Computed tomography

scans remain the gold standard imaging modality.

Cranial vault remodeling achieves the desired cranial

contour without relying on underlying brain expansion,

thus allowing treatment for older children.

Minimally invasive alternatives such as strip

craniectomy with helmet therapy are limited to patients

under 6 months of age, as they rely on rapid brain

expansion to achieve the desired cranial shape.

FIGURE 1.

6-month-old male with metopic synostosis.

Management of nonsyndromic craniosynostosis

Okada and Gosain

1068-9508 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins