Internal Distraction Osteogenesis With Piezosurgery Oblique Osteotomy of Supraorbital Margin of Frontal Bone for the Treatment of Unilateral Coronal Synostosis

Purpose: To assess the utility of internal distraction osteogenesis with Piezosurgery oblique osteotomy of supraorbital margin of frontal bone for the treatment of unilateral coronal synostosis and to study the outcome and complications of this procedure. Oblique osteotomy allows for entry into the cranial cavity, and along with parallel cut to the roof of the orbit, avoids the need to cut into the orbit which forms the frontal flap. Methods: Oblique osteotomy was performed along the supraorbital rim to do a frontal suture of the glabella (ages of patients were less than 1 year) or on the opposite side of the supraorbital rim (ages of patients were older than 1 year) after performing a suturectomy of the effected coronal suture. Two internal distraction devices were subsequently placed across the osteotomized, fused coronal suture. Finally, the cranium pieces were divided in the middle and placed in the middle of the frontal bone using biological glue. Five days after the operation, a 0.6-mm distraction was done twice daily. The distraction was removed 6 months after reaching 2 to 3 cm. Results: Internal distraction osteogenesis with supraorbital oblique osteotomy was performed in 9 patients suffering from unilateral coronal synostosis. Eight patients had no postoperative infections around the shaft puncture wounds. One patient had infection in the rods around the distraction during the period of fixed, but was cured with antibiotic treatment. During a mean follow-up period of 12 months (5-26 months), all patients were satisfied with the cosmetic and functional results. No complications, including fixed screw displacement, penetration of the cranium and dura mater or retraction of distraction devices, occurred. The devices were exposed in 1 patient, resulting in a postoperative scar. Despite these complications, the cranium was successfully expanded in all patients. Conclusions: Use of this procedure avoids the need for frontal osteotomy to move the orbit forward. Adding 2 cranium strips can be used to reconstruct the frontal nodule to make up for inadequacy of the frontal nodules highlighting to distract operation. Retracting a separated cranium is not easy after it has been fixed for 6 months. Thus, the management of unilateral coronal synostosis using internal distraction osteogenesis with supraorbital oblique osteotomy is safe and effective.