Metopic Synostosis

Premature closure of the metopic suture causes a narrow and flattened frontal bone. There is temporal narrowing, recession of the superior orbital rims and varying degrees of hypotelor-ism (Fig. 25.2a). Often, there is a prominent metopic ridge. Compensatory growth at the coronal sutures occurs away from the metopic suture, expanding the parietal bones. Compensatory growth also occurs symmetrically at the sagittal suture and further enlarges the parietal bones.

The extent of the surgical correction varies greatly for this disorder. At times, when the compensatory growth and hypotelorism are mild and only a large metopic ridge is evident, the surgery involves only burring down the stenotic ridge. More involved techniques are required when the full range of primary and secondary effects of suture closure are evident (Fig. 25.2). Surgery must restore normal contour to the forehead, bringing the orbital rims forward, widen the skull in the temporal region and attend to the hypotelorism.

Children are placed supine and a bi-coronal incision is fashioned. To minimize blood loss, dissection is carried out in a supra-periosteal plane, to a level approximately 1 cm above the supraorbital ridges. A sub-periosteal plane is then developed in continuity with the perior-bita, exposing the supraorbital rims. The tem-poralis muscle is elevated and the frontal process of the zygoma and the inferior orbital rim are exposed. The hypoplastic frontal bone is generally addressed first. A bi-fronto-parietal craniotomy that includes the coronal suture is fashioned, with an attempt to remove the bone as a single unit (Fig. 25.2b). This flap is refashioned using radial osteotomies, controlled fractures and the Tessier rib bender.

To perform the orbital advancement, the orbital rims are removed in a single unit. Bilateral orbital osteotomies are fashioned through the orbital roof and the lateral-orbital wall below the fronto-zygomatic suture. Bone graft is used to refashion the orbital rims and to correct the hypotelorism (Fig. 25.2c and d). When advancing the orbital rims, it is important to re-attach the temporalis muscle anteriorly to prevent the appearance of temporal wasting post-operatively (Fig. 25.3e). The re-contoured frontal craniotomy is then fixed to the orbital rims. This flap is most often not fixed posteriorly, in order to allow the expanding brain to move the frontal bone and orbital rims as a single unit. If the skull continues to appear narrow, barrel-stave osteotomies may be out-fractured in the temporal bone.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

Get My Free Ebook


Post a comment