Effects of different surgical techniques on cephalic index and intracranial volume in isolated bilateral coronal synostosis model

Abstract

Background: Bilateral coronal synostosis (brachycephaly) is the most common single-suture synostosis that may lead to functional deficits such as mental retardation. This increases the importance of volume gain during surgery. This study was designed to understand the differences in volume gain, cranial index (CI), and aesthetic outcomes when additional osteotomies or rotations are applied on the frontoparietal segment.

Methods: Acrylic brachycephaly models were prepared. Frontoparietal osteotomy was standard in all models. Frontoparietal segment was fixed: to the same position in surgical control model, after 1.2-cm advancement in advancement model, after 180-degree rotation without advancement in rotation model, after 180-degree rotation plus a horizontal osteotomy and 1.2-cm advancement in rotation plus angled advancement model, and after a horizontal osteotomy without rotation and 1.2-cm advancement and in angled advancement model.

Results: Intracranial volume changes (in milliliters) and CIs were as follows between groups: control group, 828/94.1; surgical control group, 830/93.8; advancement model, 900/84.5; rotation model, 834/89.1; rotation plus angled advancement model, 897/82.7; angled advancement model, 902/81.8.

Conclusions: Advancement of the frontoparietal segment is the keystone of surgery in brachycephaly treatment. Making an additional horizontal osteotomy can angle this segment and may supply additional volume gain. Rotation of the frontoparietal segment does not provide additional volume or CI gain but increase better aesthetic outcomes.