1249 A 3D Morphable Model of the Apert Mandible

Aim Assess the three-dimensional Morphable Model (3DMM) of the Apert mandible, investigate differences between sex and age, and characterise growth by age. Additionally, compare with a healthy mandible 3DMM. Method High-quality CT scans of children with Apert’s Syndrome (without previous mandibular surgery) between November1987-January2020 were sourced from Great Ormond Street (GOSH) and Necker Hospitals. DICOM files were constructed to 3D meshes through isolation of mandibles and artifact removal (MeshMixer, Mimics) and annotation using standardized landmarks (Wrapped). A 3DMM was constructed using an existing pipeline, and experiments performed to compare with the healthy mandible 3DMM, investigating differences between sex and age, and to characterise growth by age. A healthy mandible 3DMM has been created by our team using healthy mandible CT scans sourced from a GOSH database. Results A 3DMM of the unoperated Apert mandible was successfully constructed from 276 Apert CT scans, male=137 (aged0-20), female=139 (aged0-23), and the first components of the morphable model identified. Conclusions Apert’s Syndrome is a rare genetic condition, with characteristic extremity (syndactyly) and craniofacial features (craniosynostosis), however breathing problems, sleep apnoea, relative prognathism and Angle class III malocclusion have been reported. Few studies have analysed the potential role of the Apert mandible. 3DMMs are statistical tools used to represent 3D shapes and have been used to create shape and texture parameters for anatomical areas. The 3DMM of the unoperated Apert mandible has potential applications for further understanding of Apert’s Syndrome, diagnostic purposes and may be used to develop further management of these patients, such as surgical planning.