S3-04 SESSION 3: FACIOCRANIOSYNOSTOSIS – PART I EARLY CRANIOFACIAL GROWTH IN SYNDROMIC SYNOSTOSIS: IMPLICATIONS FOR ADVANCEMENT PROCEDURES

Abstract

Introduction: As subcranial and transcranial advancements become possible at younger ages, it is important to better understand the growth profile of syndromic synostosis in the first years of life to influence decision-making on surgical timing. The objective of this study is to create a growth plot of midface and mandible growth in untreated Crouzon patients to determine if vertical and horizontal growth is linear or multiphasic. Methods: We performed a retrospective review of all patients who had CT scans performed in our Center with the diagnosis of Crouzon syndrome. Images after any subcranial or transcranial midface surgeries were excluded. Using custom Slicer software, we automatically aligned the scans to a Frankfort Horizontal plane (bilateral porion and left orbitale) and measured the orbital length (sella to orbitale), maxillary length (sella to nasal spine), maxillary height (nasion to nasal spine), and effective mandible length (sella to gnathion). Distances were plotted against age for linear regression analysis. Results: We included 24 patients with 57 scans at ages 0 to 8.5 years. On scatter plots of facial dimensions, the best-fit linear regression for variables were two age lines 0-2yr and 2-8yr (* p<0.05). Conclusion: The Crouzon cohort demonstrated both horizontal and vertical midface growth over the first two years of life. After two years, the rate of vertical growth continued but decreased, and horizontal growth plateaued. Of interest, mandible length followed the same abnormal growth profile of midface vertical growth, suggesting that growth restriction is bi-maxillary in these patients. Clinical midface deficiency resulting from deficient maxillary horizontal growth may mask absolute retrognathia. This work is continuing to include other craniofacial syndromes and to compare to age-matched normal controls to increase our understanding of differential maxillomandibular growth charts in these complex cases.